Newsgroups: rec.bicycles.tech,uk.rec.cycling
From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Respoking wheels
Date: 5 Jan 1996

Roger Marquis writes:

>> Butted or swaged spokes have an advantage for wheels durability
>> because the highest stress is not in the elbows and threads but in
>> the midspan where it has little effect on spoke failure.

> Actually the worst enemy of wheel strength is cause by spoke stretch,
> which occurs along the entire length of the spoke.  Butted spokes
> reinforce the failure points but straight, 2.0mm spoke will build a
> stronger, if heavier, wheel.

What does spoke stretch do to wheel strength that is a "worst enemy"?
Your use of the term "stronger wheel", unqualified as it is, is
misleading.  I don't disagree that straight gauge spokes produce a
wheel with a higher collapse force but most wheel failures are spoke
failures and these are the rider's worst enemy.

Swaged spokes are commonly used in industry in the form of "strain
bolts" or studs that are similarly thin in their midspans.  Without
these, many high performance engines could not perform safely as they
do in racing cars and aircraft.  The effect is that cyclic loads cause
strain in the thinnest cross section, a cross section should not be in
threads and other features, that would additionally concentrate
stress.

Classic for such failures was the VW beetle when strain studs were no
longer used for their cylinder heads.  They promptly began blowing out
head gaskets because the threads pulled out of the engine block.  The
blop...blop...blop exhaust blast from the head joint was a common
sound among the last of their numbers.  This shows that there also are
people in Wolfsburg who do not understand the concept.

Jobst Brandt      <jbrandt@hpl.hp.com> 

Newsgroups: rec.bicycles.tech,uk.rec.cycling
From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Respoking wheels
Date: Mon, 8 Jan 1996 22:52:20 GMT

Melissa G. Kepner writes:

> I guess I'm not sure what you're referring to here.  The air-cooled
> VWs haven't used head gaskets since the demise of the 36 hp engine in 
> "59 or so.  The 36 hp and under engines were underpowered for sure,
> but would run forever with normal maintenance.  They never had a head
> gasket problem.  Studs pulling out of cases started in 68 or so with
> the larger 1600 cc engine and the higher heat load that came with
> pollution controls.  VW attacked this two ways: they introduced
> smaller diameter studs (and steel case inserts) in '73, and a
> different case alloy (still magnesium based) a couple of years later.

The blowout occurs there where the cylinder barrel seats on the head
and it was caused by thermal stress that exceeded the strength of the
threads because there was insufficient elasticity in the studs.
Porsche and older VW's used strain studs in this application.
Aircraft engines still do.  These studs are about the same diameter as
the root of the thread.

> If I understand your point correctly, you would call this late stud
> a "strain stud."  In this case it is thinner so it can stretch
> elastically as the engine warms up while still putting less stress on
> the case.

Yes, the slender section protects the threads from peak stress because
the slender shaft permits safe strain without overloading the critical
points.

>> The blop...blop...blop exhaust blast from the head joint was a
>> common sound among the last of their numbers.  This shows that
>> there also are people in Wolfsburg who do not understand the
>> concept.

> I think you have underestimated them.

I don't think so.  I worked in Stuttgart in the R/D department at
Porsche for four years fighting just such problems that came to us
from Wolfsburg.

Jobst Brandt      <jbrandt@hpl.hp.com> 

Newsgroups: rec.bicycles.tech,uk.rec.cycling
From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Respoking wheels
Date: Fri, 12 Jan 1996 01:05:41 GMT

Jim Adney writes:

>> I don't think so.  I worked in Stuttgart in the R/D department at
>> Porsche for four years fighting just such problems that came to us
>> from Wolfsburg.

> Just curious.  Which 4 years?

1960-1964, the 804 F1 and 904 GT years.

Jobst Brandt      <jbrandt@hpl.hp.com> 

Newsgroups: rec.bicycles.tech,uk.rec.cycling
From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Respoking wheels
Date: Mon, 15 Jan 1996 16:15:57 GMT

Melissa G. Kepner writes:

>> 1960-1964, the 804 F1 and 904 GT years.

> For VW these were the first years for the 1200 cc/40 PS engine.  As
> I recall they had a problem with cam followers and valve guides in
> that era.  Can you shed any light on their efforts?

I'm not sure there was any special time for difficulties, they
occurred all the time because practically everything on the car was
marginally designed.  You'll note that the pushrods (and the tubes)
angle upward to the rocker boxes, indicating that they are not 180
degrees apart as is necessary to run two valves from a common lobe of
the cam (one of the many 'clever' ideas).  The tappets were originally
angled upward, keyed against rotation, and had large-radius angled cam
following faces to affect the 180 degree orientation.

Non rotating (keyed) tappets gall easily, and as the valves and rpm
increased with larger bore engines, cams failed regularly.  At this
time the rotating tappet was introduced with its flat mushroom head.
These tappets were horizontal (180 degrees apart) but the pushrods
remained angled, thus putting a side load on the tappet that
subsequently made the classic VW clank and valve rattle as the tappets
canted in their bores.

Valve guide problems always plagued these engines because their air
cooling could not adequately the heads to assure lubrication.  The
whole engine was a mix of motorcycle design features and badly
transferred techniques that, at first glance, have some appeal but
were not used by any reliable engines even at that time.  Valves
of cylinder #3 left front burned regularly because the oile cooler
(air preheater) blocked air flow to that part of the head.

You may recall that one of the great VW adds claimed they could pull
the engine out in 13 minutes.  Well, they had to.  Any VW shop you
visited had most of the engines out of the cars being worked on.  I
have never had the engine out of my 100,000 mile cars I have owned
since... or needed to pull off the head.  

The whole VW aura was kept alive by CEO Nordhoff who seemed to believe
that the car was handed to him on Mt. Ararat from the heavens by
Ferdinand Porsche and was infallible.  I believe, had he lived another
five years, the company would not have survived.  It was a close
scrape with death anyway when Fiala came on board, scrapped the
beetle, its air cooled rear engined follower and turned to the
Golf/Rabbit that had been developed in their special products
department for theoretical projects.

Although Porsche used essentially the same engine in the 356 cars,
substantial modifications were made to keep the engine together.
Nordhoff rejected nearly every one of these changes although most
could have been introduced at no cost when design changes were made.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Facts, Statistics, and Lies
Date: Thu, 21 Nov 1996
newsgroups: rec.bicycles.misc,rec.bicycles.tech,rec.bicycles.racing,rec.bicycles.off-road

Bruce Hildenbrand writes:

> Yeah, kind of like last year when you, Jobst, were talking about how
> dangerous Campy Deltas brake were and you basically said that you could
> get seriously hurt by using them.  This point was in direct contention
> with the fact that nobody stepped forward to give first, second or
> even the dreaded third-hand accounts of *any* serious bike accidents
> directly attributed to using Campy Delta brakes.

I stand by my description of the design error of this brake for good
reason.  Having worked in the development of brakes and understanding
the nature of variable ratio, I have no reason to believe otherwise.
If you choose to descend mountain roads with it, that's your
prerogative.  The sponsored teams chose not to, and Campagnolo
ultimately withdrew the product.  They did not redesign it.  As I
said, I wrote an article about the problems of this brake years ago
when Modolo first presented it as the Chronos.

> Furthermore, it was pointed out that at least four(4) Tours de France
> were won using Campy Delta brakes and that the brakes were available
> on the market for over 5 years.

It has also been won by Oakley glasses.  If that's your measure.

> Still, you continued to support your claims with such incredibly
> powerful statements like:

>    "That the Delta brake was a hazard was not apparent to Campagnolo
>    or the riders until the results were in.  They are and the brake
>    is out."

That is correct.  Please explain what you know to the contrary about
the response of this brake.  Do you believe that a variable ratio
brake is acceptable for descending mountain roads?  If so, you have
different criteria than the brake industry.  That Campagnolo has been
in mechanical doldrums is apparent by their lack of innovation and
following of trends set by Shimano.  The Delta apparently was to be a
counterattack that failed.

> Gee, it sure took a long time to get the results given that the brakes
> were on the market for over 5 years.  You would think if the brake was
> really a hazard, Campy, et. al. would have realized it right away and
> done a product recall.  I never saw a product recall of this Delta brake.

You don't know how soon individual riders decided to use other brakes
after undesirable performance.  That they did so was corroborated by
others who joined the discussion.  On the other hand there are many
riders who never press the limits of cornering.  As we have seen, tour
winners like Bahamontes were such poor descenders they lost several
minutes on mountains where they had been KOM on the ascent.  Not all
riders are in a position to know how bad a brake is, never using them
to such limits.

If you think Campagnolo took long to admit the error, how about
Porsche taking 30 years to give up on air cooling.  In the 1960's it
was known in the racing department that without water cooling, they
would never match the power of the Climax V8's.  First water cooled
heads then at long last the water cooled engine.  It was a long hard
battle and heads rolled for suggesting a change.  You see what
happened to Dr Fuhrman and his water cooled 928.  The ax.

> So, Jobst, what's your point?

What's yours?  I didn't realize you felt so strongly about that brake.
If you had access to someone from the brake industry, you could ask an
impartial expert about the relative merit of a brake with the variable
ratio like the Delta, and hear the same thing.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.misc,rec.bicycles.tech,rec.bicycles.racing,
	rec.bicycles.off-road
Subject: Re: Facts, Statistics, and Lies
Date: 26 Nov 1996 00:28:44 GMT

Kyle Disque writes:

>>>> If you think Campagnolo took long to admit the error, how about
>>>> Porsche taking 30 years to give up on air cooling.  In the 1960's it
>>>> was known in the racing department that without water cooling, they
>>>> would never match the power of the Climax V8's.  First water cooled
>>>> heads then at long last the water cooled engine.  It was a long hard
>>>> battle and heads rolled for suggesting a change.  You see what
>>>> happened to Dr Fuhrman and his water cooled 928.  The ax.

>>> Folks, please understand that this is absolute crap, hooey of the
>>> first order.

>> Please present a thread of evidence for this contention.

> The move to water cooling was not an "admission of a error", it was 
> necessary to support the increased horsepower gained from tuning and
> increased displacement.

Cooling has always been necessary in engines and air cooling has
always been a fetish with some designers who had a problem with water
somewhere along the way.  It cost Porsche extreme effort to keep air
cooled vehicles running in races to the extent that they were to a
large degree oil cooled engines putting a large part of their cooling
through the oil cooler.  Cracked heads and burned valves were common.
The problem of a piece by piece assembled engine of crank housing,
cylinders, heads, cam chambers and interconnecting oilways was an
uncalled for expense that gained nothing in reliability.

> Maybe your contention that the Porsche racing effort was greatly hindered
> by this "error" is supported by their poor results in the 60s?  NOT.
> I recall that the Holberts earned the title of "World's most winning
> sports car racer" in those very "underpowered" cars.  This is, in the end,
> a matter of opinion.  I doubt that either of us will change the other's
> mind.  Let's get back to the purpose of this thread.

Porsche, through their years of rear engine cars had developed a great
understanding of chassis design that was in ways ahead of some
competitors mainly because these cars were so difficult to handle.  As
a reaction, much effort was expended in that field to good advantage.
Intense effort and good teamwork made the effort successful, not air
cooling.  You'll note that the TAG V-6 was not air cooled nor were
subsequent racing engines.  There never was a good reason for air
cooling nor the torsion bars and swing axles other than they were the
rage when the VW was conceived.  The success of the VW made many
people believe that this was the way to build cars.  They were labor
intensive and required individual craftsmanship make them work.  Most
companies, other than the ones who felt it part of their identity, got
off that track in a hurry.  Porsche even used mixed cooling with water
on the heads, air on the cylinders and oil, to bridge the gap.

> Jobst, you sound like what you are; a bitter ex-employee.

You may see it that way but I enjoyed the time I spent there because I
learned much.  If you don't make mistakes you don't learn.  I came
into the job believing in the excellence of the concept and gradually
learned about the problems they had and how they were solved.

> Please stop diminishing the value of your contributions in order to
> maintain your exaggerated ego.

You may be expecting more value from my contributions than is there at
the expense of the ones with which you disagree.  I haven't changed my
assessment of engineering as I see it, be that brakes, press fits,
patching tires, drifting bicycles on pavement, or about the traditions
at Porsche KG.

> Your advise and opinions are more often than not helpful and
> correct.  It's your inability to accept that these contributions
> might be less than perfect that we're objecting to.  I, for one,
> would not prefer that you go away, but that you lighten up.

I suspect you hold Porsche engineering in unduly high esteem and that
I am an iconoclast.  Over the years I have heard the tone of reverence
by the followers, and understand that questioning any of these beliefs
is blasphemy.  Engineering efforts are often formed by personalities
that have their fetishes.  At Porsche the sacred cow was the VW Beetle
and it was a long time in vanishing.  The VW Company was saved only by
Dr Fiala axing everything that was left of the Beetle, all at once.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: History of Campy Delta Brakes
Date: 10 Oct 1996 02:49:11 GMT

Chris Fabri writes:

> I was trying to point out that while having the exact same handling
> characteristics, the Corvair garnered the (unearned) reputation of
> "unsafe at any speed," while the 911 is regarded as one of the best
> performing sports cars in the world.

There is little parallel between a Corvair and a Porsche, because they
use a completely different geometry.  The Corvairs that earned the
reputation were those that had the original rear axle that changed the
tread of the car substantially when in a turn, and had no equalizing
spring that was offered only as an option.  That the rear engined
Porsches oversteer is evident but its response is nothing like a
Corvair.  In fact a skilled driver trying for a good lap time in a
Corvair on any race course would avoid the attempt because it is so
risky.

> As you pointed out, it's the driver, not the car.  And, just like
> with the Campy Deltas, if you don't know the limitations of your
> machine, you're going to get yourself in a heap of trouble. 

That is wishful thinking.  Enough ordinary drivers rolled their
Corvairs doing nothing more than driving around a highway on-ramp.
That is not "the driver".  The same is true of a bicycle brake with a
accelerating mechanical advantage as the Delta brake has.  Without
realizing it, the user can suddenly find 30% more braking occurring
than was anticipated.  That is not the rider.  It's the brake.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: Sep 04 1997
Newsgroups: rec.bicycles.tech

Aaron Byerley writes:

> I am developing a new course which uses bicycles to introduce the main
> topics that constitute the discipline of mechanical engineering
> (statics, dynamics, material science, fluid mechanics, machine design,
> etc.)  As a part of this course I plan to have each student team
> "dissect" a bicycle for much the same reason that biologists dissect
> frogs (to study, sketch, understand the component purpose and
> relationship to other components,etc.)

As you may have noticed here, much of what a bicycle does is not well
understood even by those who build them, and design components for
them.  Classically, the workings of the wire spoked wheel were not
understood or analyzed before I published my book on the subject.
Even professors of mechanical engineering doubted the concept that
wire spoked wheel stand on their bottom spokes, by relaxing their
tension while adding no stress to any other spokes.

> I suspect that something like this has been done before.  If anyone
> knows of such a course, I would greatly appreciate some info.  Many
> thanks.

I find the Volkswagen Beetle a far better instrument for this
exercise, because it is a compendium of all the things one should not
do in designing a car.  You can start at the front bumper and work
back through the suspension, steering, ventilation, door hinges, seat
supports, and finally the disaster of the engine and drivetrain that
are full of selective fits and mechanisms that have a high maintenance
factor.  The gear box, differential, axles, and hubs are all designs
that had long since been discarded by other manufacturers for obvious
reasons.

Of course the idea of rear engine, air cooling, and the use of torsion
bars, should not be overlooked.  There are many reasons why no one
else does this.  Porsche belatedly gave up on air cooling today,
years after they were the only holdover.

For students to study these components and write essays on why one
should not do this or that found in the VW would be useful.  Much of
the bicycle, in contrast, is fashion and is difficult to separate
from function because so many bicycles are owned but not operated.

The owners will lie about their prowess and use, so they are no help.
Professional racers are not engineers, so they are mostly no help, and
they ride anything the sponsor offers, that works, fits, and doesn't
get in the way.  Therefore they ride many fragile parts that are
replaced on a regular basis by team mechanics.  Meanwhile the gullible
public buys the stuff that "works" without failure because they
mostly don't subject it to its supposed design loads and duration.

If you attend the annual Interbike show in Anaheim CA this week, you
will see many examples of this syndrome.  It is an inventor's paradise
with the whackiest contraptions, some of which go to market for years.
The Centerpull brake was one of these.  It had NO advantage over
existing caliper brakes of the day, had the same mechanical advantage
but was heavier, harder to adjust, and had severe cosine error as the
pads wore, requiring repeated pad adjustment, something that sidepull
brakes never need.  Campagnolo with the Record caliper (side pull)
finally displaced it and it never returned.

The Modolo Chronos, later brought to market by Campagnolo as the
Delta, was a similar blunder that went away after years of problems
but many believers.  Today this brake is admired by many who have
never used it at the level where it becomes dangerous through its
variable ratio linkage that changes ratio from zero to infinity at the
extremes of motion.  It has vanished and we'll never see it again.

> Aaron R. Byerley, Assoc. Prof., Mercer University School of
> Engineering

Where is Mercer?

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: 8 Sep 1997 19:23:38 GMT

Stella Hackell writes:

>> I find the Volkswagen Beetle a far better instrument for this
>> exercise, because it is a compendium of all the things one should not
>> do in designing a car.  . . .

>> For students to study these components and write essays on why one
>> should not do this or that found in the VW would be useful.

> They could also study the remarkable longevity of VW Bugs and
> try to figure out how a car with so many lousy designs can last
> so long. Here in northern Calif., I see many 20- to 35-year-old
> Bugs on the road, and not all of them are owned by shade-tree
> mechanics. I'm not qualified to judge their engineering; I
> just see a lot of them chugging along.

Yes and they all fail to meet minimum performance standards that
people who drive cars require, like for instance the blown head seals
that occur because cylinder #3 gets hardly any cooling air, being
hidden behind the oil cooler, and because head studs, not being strain
screws, pull out of the motor block.  The list is long.  Had Nordhoff
(first director of VW) not died when he did, the company would have
gone bankrupt.  In the last moment his followup beetle was canceled
in favor of the Golf that had nothing in common with the Beetle except
that it was a car.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: Sep 08 1997
Newsgroups: rec.bicycles.tech

Brad Anders writes:

> Jobst, exactly what did they do to you at Porsche? :-) 

I worked on that stuff and it was a constant fire drill where you were
not allowed to put water on certain places (subjects) that were sacred.

> You imply that all of these ideas are gigantic failures, but if so,
> why is the car that they were implemented on one of the most successful
> sports car of all time  (911 series)? A car with countless wins in 
> competition, dozens of top ratings from enthusiast magazines, and 
> a rabidly devoted owner base? Wouldn't you agree that in the final 
> evolutions of the 911 (say, from about 1980 onwards) that most if not 
> all of the problems with the engine, configuration, and suspension were
> solved? 

Per mile driven and the base price of the car, it could be one of the
most expensive medium production cars.  That people like mystique is
shown in the bike industry even more.  There are believers in products
like the Pedersen bike or certain saddles that are shunned by the
mainstream.  Porsche is a religion and an image.  I for one would
feel a bit silly driving around in a car with a huge aerodynamic
device on the rear and tires wide enough for a dragster.  The success
of this car is more its exclusivity than any technical aspect.  The
rear engine car is not found anywhere else in racing for good reasons.
Mid engine, yes, but rear engine is a dud.

> Before I left the Bay Area, I finally found a good Porsche mechanic to 
> work on my car (914 with ancient D-Jetronic injection). I will make no
> attempts to defend the problems with my 914 from a design standpoint, 
> BTW :-). He was an experienced mechanic who had been trained by Porsche
> and Audi, and his shop worked only on air-cooled Porsches. I asked him 
> why he didn't work on 924/944/928's and his response was that they were
> a maintenance nightmare in comparison to 911's.

So he didn't know how to care for these cars.  I recall that most of
the cars in the service bays at Porsche had their engines out and even
transmissions.  The one I once had suffered similar needs.  The amount
of deep maintenance was impressive.  My Volvo has never had the motor
out or for that matter opened.  No one has adjusted the overhead cam
valves since 1978.

> The later 911 engines were amazingly reliable (according to him) and
> the bottom ends were 100% bulletproof (he had customers with 250K+
> on untouched cases).  Given Porsche's record with water-cooled
> street cars, and the limited experience with the promising Boxter
> engine, what gives you great confidence that Porsche's move to all
> water-cooled engines will be an improvement?

The immediate jump in power that was realized without effort when
switching to water cooling is one item.  The other is that the 928 was
probably their best car and was always a stepchild because it violated
the unspoken rules that I mentioned before.  At the factory when
taking a company car, the 928's were always in high demand because
they were relaxing and comfortable to drive in contrast to the twitchy
rear engine 911's and derivatives that also had an unacceptable noise
level.

> In contrast, other high performance cars comparable to 911's have
> horrible reliability and maintenance records (anything Italian, for
> example...). I would agree that Japanese sports cars (NSX, recent
> Supra Turbos) are far more reliable. Isn't all of this issue not so
> much a matter of a particular design, but the proper and
> well-engineered implementation of the concept?

The air cooled concept cannot be well implemented.  If I give you
several heat sources and one fan to cool them you can imagine how hard
it would be to bring them to a continuous and desirable temperature.
With water they can easily be held at 200 degrees F with little
difficulty.  That's only one part.  Just imagine casting a motor block
and cylinders and sealing all the joints.  No one has seriously
thought of doing that in many years except Porsche.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: Sep 08 1997
Newsgroups: rec.bicycles.tech

Mike Kohlbrenner writes:

[about the VW beetle]

> With all due respect, I find it somewhat ironic that you have chosen
> the automobile which not only has the record for most units of a
> single design sold, but was designed in the 1930's (!) and is STILL
> built and sold in Mexico.

This car was a monument to the service network and size of the car
that filled a much needed gap in the automotive inventory.  The
service network above all was its greatest selling point.  It came
along after the WW-II and as most of us who recall that era will
recall, boiling radiators were the norm when traveling over any
mountains.  The air cooling appealed to people who suffered the steam.

I worked on these cars, both the boiling cars of the 30's and 40's and
the VW Beetle.  This is one of the ways I developed my engineering
skills.  I could find hard proof that these cars had fatal flaws.  The
boiling cars had no reasonable water pump seal and were always low on
water, something that became apparent only when driving to the beach
over the hills around here.  Our mountains, as the Alps, still have
roadside springs with pipes sticking out, for radiator service.

The VW was the first postwar car to advertise "no more geysers",
something that appealed to most people, and they had a terrific service
network that fixed your car in a short time.  In fact they were in the
shop so often that major problems were often caught at inspections,
something most people didn't do then.  Of course that the carbon seal
water pump was invented during the military buildup was not known, so
we had a solution to a problem that had gone away with the war and
didn't come back.

> I do completely agree with you that the Bug design does not meet many
> of the design constraints one would place on an automobile TODAY, but
> if measured by the design constraints and technology of the period in
> which it was designed, it was actually quite a good design, as
> evidenced by the number sold and its reputation as simple, reliable,
> inexpensive transportation.

It did not meet manufacturing goals for that time either.  The car
came from Czechoslovakia, Ferdinand Porsche's native country, where it
had served as a non spectacular vehicle.  It had many unconventional
design features that are to be found nowhere today and hardly at that
time because they had been found wanting.  This includes parallel
tailing link front suspension, diagonal swing axles ion the rear,
torsion bar springs, engine behind the rear wheels, air cooling, and
what appeared to be an aerodynamic form, which it wasn't, but because
it had a heavy rear end and the incompatible front and rear
suspension, it was dangerous in even slight cross winds.  To compound
that, it was a dangerously oversteering car that magnified any
steering motion by having the rear swing out in a curve.

> If you are to use the Beetle as a design example, I would suggest
> rather writing essays on just why such a reputedly poor design could
> have lasted so long.

It had great public appeal for going against what Americans had become
to accept as the status quo from Detroit.  There was no other small
car that would keep on running and the Germans made sure they kept on
running.  That was the great feature.  I once had engine problems for
which the shop needed a week.  They stuck a loaner engine in my bug
and I missed only a couple of days.  Service was everything and to show
what the opposite is, look at FIAT aka "Fix It Again Tony" they never
had parts and there was no service net, while VW had Tschermans
behind the counter.  FIAT pulled out.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: 9 Sep 1997 22:32:39 GMT

Mike Kohlbrenner writes:

> My only point was that for all the imperfect designs in the history
> of the automobile, you happened to select the one with the most
> sales and the longest continuous build history as the one to use
> as an example of bad engineering.

It was maybe that although I am not sure that is accurate since no
other car company focused on one model as long and hard as VW.  The
car achieved its fame in spite of its mechanical problems, many of
which I was employed to correct when I worked at Porsche.

For instance, it is hard to understand how a car without a heater was
sold so widely.  In cold weather there was no heat and all available
warm air was piped to the windshield to develop a 3x6 inch viewport
in the ice (on the inside).  The temperature rise across the engine
was the same in hot or cold weather, so a 20C rise was still below
freezing on a cold day.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: 9 Sep 1997 00:26:04 GMT

Mike Kohlbrenner writes:

>>> You imply that all of these ideas are gigantic failures, but if
>>> so, why is the car that they were implemented on one of the most
>>> successful sports car of all time (911 series)? ...

>> ...  Porsche is a religion and an image.  I for one would
>> feel a bit silly driving around in a car with a huge aerodynamic
>> device on the rear and tires wide enough for a dragster.

> And yet it IS a sports car and both of those features have very
> sound reasons for their existence.

Oh, at what speed do you think these devices come to play and why do I
need them when other cars on the road seem to to lift off in the
curves as I drive to the beach in my station wagon behind one of these
sport wagons?

>>  The success of this car is more its exclusivity than any
>> technical aspect.

> I will certainly not deny that many Porsche purchasers are more
> poseur than anything else, but you cannot deny that the 911 in
> atmo or turbo form is one formidable performer as a sports car.

Not the ones that cruise around here.  They do best on the main street
roaring by at 20mph in low gear... stuck in slow traffic.

> > ...  The other is that the 928 was probably their best car

> Best car for what?  Certainly not racing.  The 911 is a true sports
> car.  The 928 is a grand touring car.  Completely different beasts.

It was a comfortable and well balanced sports car.  As I said, it was
a step child, never accepted by the inner circle, and it also lead to
the dismissal of Dr Fuhrman who was responsible for it coming to life.
He was the man who, in his early days at Porsche, headed racing and
developed the 550 RS Porsches that made this small company world
famous.  The car that James Dean had.  As I see it, the front water
cooled V-engine and rear drive was too much for the company to swallow
and they seemed to take it personally.  The car was never raced or
modified for private competition, It languished in the background in
promotion as well, with back handed compliments like, "the 911 a REAL
Porsche" that had enough implications for anyone to notice.

>> and was always a stepchild because it violated the unspoken rules
>> that I mentioned before.  At the factory when taking a company car,
>> the 928's were always in high demand because they were relaxing and
>> comfortable to drive in contrast to the twitchy rear engine 911's
>> and derivatives that also had an unacceptable noise level.

> Some would consider that "noise" music -- I do.  But I tend to
> agree that for a blast down the autobahnen, the 928 is probably
> more relaxing.  For a blast at the Nurburgring, it would be 911
> all the way.

Yes the Tifosi do that, and they are complaining that the whining
thrash of the "true Porsche sound" has been destroyed.  Most of these
people do not drive one of these beasts, but adore the image.  I put
away enough miles in both Porsches and VW air-cooled cars and I don't
care to hear any more of it.

> It is true that the 911 is a design long held over from days gone
> by.  But they still seem to sell pretty well, so why not keep
> building them?

The Tifosi even complain about the new styling of the water cooled 911.
I think it's beginning to look more civilized but it's still a rear
engine car, for which there is no excuse.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mesh. engr. topics
Date: Sep 09 1997
Newsgroups: rec.bicycles.tech

Brad Anders writes:

> Meanwhile, air cooled Porsches continued to win every conceivable kind of
> endurance race. The success of the 904 (your baby), 906, 908, 911, 914/6,
> 917, 934, 935, 956, and 962's against every conceivable kind of water
> cooled opposition is well-documented. Many of these wins were not from
> sheer speed, but were due to the high reliability of these cars. If these
> problems were so intractable, how did these cars continue to defeat  all
> opposition for nearly 30 years?

Then Porsche is making another huge mistake by dropping air cooling by
that measure and the F1 cars are missing a good thing by using water
cooled cars.  I don't believe it.  These were the last air cooled cars
and then there were none.  We'll have to see what they accomplish with
the new medium.

> Look, Jobst, I know you dislike the 911 design and air cooled engines in 
> general. But to write these cars off as immense engineering failures is
> to ignore the current state of the cars and their competition record. 

Well someone changed subjects in the middle of the stream, and I think
it was you.  I said the VW Beetle was a design blunder from front to
rear, and that each of its "features" would be good experience for
students looking into a career as mechanical designers.  

When I was in high school, I worked on Model-A Fords and discovered
that they were much like the Beetles I ran into years later.  The A
was a derivative of the excellently engineered T, but with all the
concepts divorced from their function.  This resulted in major part
failures that I only discovered when searching the junk yards for
spare parts.  All of them were broken and in the same place.  Most
people assumed the A was just a newer T, but the similarity was only
visual.  Mechanically A's were terrible duds in contrast.

The reason we relive history is that we don't learn from it.  The same
goes for mechanical designs, of which air cooled cars were dead horses
in the 1920's and came back for all the wrong reasons with the VW.
Porsche could have done well regardless of whether they had ever
considered air cooling or not.  That is not where their expertise is
based.  In the years that I worked there and talking to my old cronies
over the years, I realized they operated somewhat like a startup
company in the R&D department.  Lots of enthusiastic young car buffs
with the right background.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mech. engr. topics
Date: Sep 18 1997
Newsgroups: rec.bicycles.tech

Charlie Rockwell writes:

> Now let me see.... I have owned two Beetles, three Lotuses, one Mini,
> and three Fiats and all of these have been trashed in this thread....

You seem to have a knack for choosing losers.  The VW and FIAT lie at
opposite ends of that spectrum, the VW a poor design with excellent
parts availability and service, the FIAT a good design with no parts
availability and terrible service.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Using bicycles to introduce mech. engr. topics
Date: Sep 22 1997
Newsgroups: rec.bicycles.tech

Neil Maffenbeier writes:

> I read your rantings. You seem to have some good hands on experience,
> but your statement wrt the quality of engineering is totally baseless.

Thanks for the compliments.  Maybe you should point out what you know
about that car that was high quality engineering instead of throwing
out a blanket statement with a catchall qualifier of compromise.

> I don't know what other credentials you have but this thread hardly
> passes for a discussion on the merits of the various engineering
> ideologies.  Rather as I suggested in my initial post the ranting of
> someone involved with the inappropriate use of a design.  All
> engineering involves compromises. To determine whether
> compromises were good or bad first you'd have to know what they were
> and why they were made.

So how about explaining what great accomplishments they had that
weren't better done by other cars of the day, except price.  Take for
instance their claim that their car was so air tight that you had to
open the window to close the door.  In fact they placed their rubber
seal on the leading edge of the door to make a piston of it instead of
having a rubber seal at the closure point as all other cars do.  The
car is full of such basic errors from top to bottom.

The transmissions were in a housing split lengthwise so that each half
has almost no torsional strength a channel sections normally don't.
The joint between the halves had gasket shellac that slipped and
caused endless drips.  This feature was one that Porsche corrected
because with higher torque the cases even broke.  I can recite a long
series of such blunders, quite aside from the human comfort problems.

Jobst Brandt      <jbrandt@hpl.hp.com> 

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Using bicycles to introduce mech. engr. topics
Date: 23 Sep 1997 21:40:25 GMT

Neil Maffenbeier writes:

>> All engineering involves compromises. To determine whether
>> compromises were good or bad first you'd have to know what they
>> were and why they were made.

> ... not a small cycle car but a full-size, reliable family
> car,although he proposed lighter construction techniques than normal
> in those days.  It should hold four people, have a top speed of 100
> kph, be able to climb a 30- percent hill and be built in various
> body configurations..  Herr Porsche original concept as quoted from
> VW & Porsche Mag Oct 81 issue This is the 1934-38 origins of the
> beetle. I don't know to which "day" you are referring but I would
> suggest that cars of 1934 to 1960 were not as simple reliable or
> advance as the beetle.  The beetle seems to have met this design
> criteria and the fact that the basic design survived into the 80's
> would be a testament to a good design.  Granted it didn't meet all
> the diverse requirements of north America but if we consider other
> designs of the 30' and 40's how would they compare to 70 and 80's
> autos.

The car was built in the 1950's in large production.  None of the original
problems that existed during the military production were improved and
most cars of the day had performance and comfort features that the beetle
did not.  What it had was a large German labor force that worked at tiny
wages to put out a car that stood alone in its price range.  In the USA,
where it made its big entry, it was the second car.

Prof. Porsche did not design the car nor did he invent it.  It came
from his native country, Czechoslovakia where it caught his eye and he
sold the concept to Hitler as a good propaganda item... the peoples
car.  Effectively none of the cars reached the people until after the
war, when the Western alliance helped get the factory back on its feet
and the people off the bread-lines.


>> Take for instance their claim that their car was so air tight that
>> you had to open the window to close the door.  In fact they placed
>> their rubber seal on the leading edge of the door to make a piston
>> of it instead of having a rubber seal at the closure point as all
>> other cars do.  The car is full of such basic errors from top to
>> bottom.

> From what I've read this was intended.

It was a design error that was not fixed.  What advantage do you
perceive in a car whose door cannot be closed without opening the
window?

> The fact that you don't like doesn't make it a poor design.  I
> wouldn't consider door seals to be a basic design characteristic.
> "well Ferdinand before we get going on this design we have to decide
> how were going to seal the doors" I doubt it.

Most other cars make that seal in the last moment as the latch
engages.  You may doubt this but as an engineer who worked there I
know that these were problems that were regular internal jokes.  I
have a company newspaper full of cartoons about them.

>> The transmissions were in a housing split lengthwise so that each
>> half has almost no torsional strength a channel sections normally
>> don't.  The joint between the halves had gasket shellac that
>> slipped and caused endless drips.  This feature was one that
>> Porsche corrected because with higher torque the cases even broke.
>> I can recite a long series of such blunders, quite aside from the
>> human comfort problems.

> I would hardly call this a blunder how much "torsional strength"
> would you build into a transmission designed to take 40 hp? This
> "endless dripping" out of the 15 + million or so beetles made since
> 1945 how many had this problem.

All of the ones with the the split transmission housing.  After
switching to the tunnel-housing, the thrust bearings were located in
the wrong end of the magnesium alloy box so that thermal expansion
caused havoc with the ring and pinion at the other end of the box.

> How long before it showed up. My father was a mechanic for 10 years
> for VW and 10 for Chrysler. So I have an idea of where your coming
> from.  But mechanics dentist, doctors, and police are all exposed to
> the bad cases of society the good seldom visiting them so there
> views tend to be skewed by this constant bombardment of problems.
> Which in fact may only represent a lesser portion of what is
> actually going on.

So how about torsion bar suspension?  That is a hard one to justify,
considering that no one else uses it and those who did, scrapped it in
a hurry once its vagaries were discovered.  I had to use torsion bars
in several designs and was immediately impressed with the expense and
difficulty of these springs.

> Finally you made some statement about how I had made a broad
> generalization. I may have. My point in all this is that your
> statement was also very broad based and from what I can tell you
> don't have the background to back up the statement.  Granted there
> may have been some flaws with the designed you mentioned but you
> have not provided design criteria to show that the problems you
> mention are in fact design problems.

It is not "some flaws" but a compendium of flaws in design, some of
which were ameliorated by skilled craftsmen who could make these
things work.  However, why don't you point to some high points that
made the car so great, ones that were not related to the best serviced
car and excellent parts supply?  What technical excellence comes to
mind?

> At the very least you should qualify your statement.

I think I have done so extensively.  How about pointing at where you
want more supporting evidence or detail.

> There are many "designs in making an automobile that effect the
> final product".  Whether it has to do with basic design, the
> individual component design, the manufacture design/limitations to
> generally say a design is poor you have to do a little more research
> than what you have.  Well your hands on experience is certainly a
> part of the experience it is in the end a small part in the design
> of a complex machine.

What are you getting at?  Individual design and complex machine?

> If you never tried to actually manufacture something from scratch
> you really can't appreciate the amount of compromise and process
> restriction involved.

I was involved with the design of three different cars while at
Porsche.  The 804 F1 car in a small design team in which we were held
to tradition, using air cooling, torsion bars, non roll steering rear
suspension, although we as a team would have liked to build something
else.  The 904 got coil springs and the 911, although saddled with
torsion bars got McPherson struts.  I don't know what you mean
by "never tried to actually" but I think I have enough experience to
comment on designs.

> I was involved with the CF5 wing manufacturing program in the early
> 90's it is quite surprising the amount of work required to
> manufacture something from drawings.  The wing is relatively simple
> to build compared to an auto.

So what has this to do with designs that are misplaced and known to
have problems that have no visible solution?  That air cooling was a
pain in the neck was apparent with each of the engines Porsche built.
VW, with Tony Schmuecker, dodged the air cooling battle long before
Porsche had to give it up.  It's not as though the rest of the auto
industry is full of idiots who don't recognize that the features in a
VW Beetle are superior.  The Beetle was not and only Chevrolet was
foolish enough to try to elbow in on a poor concept by going to rear
air cooled engine and swing axles in the rear.

> Well put that in your pipe and smoke it.

What are you smoking anyway?

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Using bicycles to introduce mech. engr. topics
Date: 25 Sep 1997 23:49:15 GMT

Neil Maffenbeier writes:

>> The car was built in the 1950's in large production.  None of the
>> original problems that existed during the military production were
>> improved and most cars of the day had performance and comfort
>> features that the beetle did not.
>
> This still doesn't address design issues. Were the flaws related to
> production constraints of the era?  Looking at a country that would have
> been extensively bombed what do you think the priorities of the
> people/managers/engineers of the day would be fine tuning or getting
> production initiated to making some money.

That may be an excuse, but the things I mention are design features
that had solutions in other cars built at the time.  There was a
religious zeal among the VW faithful who believed it sacrilegious to
alter anything that Prof Porsche handed down.  In fact he did not
design it nor did he design anything.  He was a concept man and and
organizer who promoted ideas that appealed to him.  His favorite was
electric drive war machines.  There are several biographies that
detail these aspects.

>> What it had was a large German labor force that worked at tiny
>> wages to put out a car that stood alone in its price range.
>
> would you have a reference I'd be interested in reading more about
> this.

I have several books at home about the old guy and his accomplishments.

>> In the USA, where it made its big entry, it was the second car.
>>  Prof. Porsche did not design the car nor did he invent it.
>
> Again a reference would be nice unfortunately I don't have the close
> association you have with the company and most of my interest was a
> few years ago and based on enthusiast sources but from what I
> remember Mr Porsche is credited with design of the beetle.

An enthusiasts club is not the place to hear about the story behind
the Volkswagen.  No wonder you are skeptical.

>> It came from his native country, Czechoslovakia where it caught his
>> eye and he sold the concept to Hitler as a good propaganda item...
>> the peoples car.
>
> There existed an automobile that was the same as the beetle that he
> copied?  Or he got an idea from something?

He brought it complete from there.  Today, VW went there to build a
production line there.  The German auto press covered it at length
citing that the circle had finally been completed.  They don't build
beetles.

>> It was a design error that was not fixed.  What advantage do you
>> perceive in a car whose door cannot be closed without opening the
>> window?
>
> I understood it had to do with sealing the door so that water wouldn't
> enter the vehicle.  A military requirement that carried through.  Once a
> design is established it often cheaper to carry on characteristic even
> if they are no longer relevant.

No, the door is no more water proof than most others.  It is the floor
of the VW that is more water proof than others, the biggest leak being
at the pedals.  The sealing lip at the leading edge of the large door
of a two door sedan with a small interior volume does this.  The trunk
of most cars is open to the air of the interior and the floors leak
considerably so other cars hardly show this problem.  Most cars have
the seal on the door jamb while the VW had it on the edge of the door
as a wiper instead of a compression seal.

>> Most other cars make that seal in the last moment as the latch
>> engages.  You may doubt this but as an engineer who worked there I
>> know that these were problems that were regular internal jokes.  I
>> have a company newspaper full of cartoons about them.

> most 50's cars I'm familiar with don't do a very good job of sealing
> period.  What era would u say that this practise became prevalent.

That doesn't change this problem that the others didn't have.

>> All of the ones with the the split transmission housing.  After
>> switching to the tunnel-housing, the thrust bearings were located in
>> the wrong end of the magnesium alloy box so that thermal expansion
>> caused havoc with the ring and pinion at the other end of the box.

> This was corrected in the 60's though if memory serves me.

That happened because at Porsche, where the same box was used, the
cases began to fail from flexing in torsion so much that not only did
the case leak oil, but it loosened the bearings that were retained
between the two halves.  Just imagine the manufacturing problems of a
split case with all the bearings in the split line.

>> So how about torsion bar suspension?  That is a hard one to justify,
>> considering that no one else uses it and those who did, scrapped it in
>
> This comment highly full of shit. You seem to be talking in
> generalities here so I feel this comparison is justified although
> the suspension system are not identical.  Chrysler used a torsion bar
> suspension for about 30 years in all manner of autos and Datsun also
> for I think about 10 years.  Again from reading I understand that
> the torsion bars suspension is light weight, compact, simple and
> transfer loads better than a coil spring suspension. hence allows a
> lighter body building techniques aka the Chryslers cars of the 60's
> and 70's.

All use of torsion bars in car suspension is without merit.  It is
conceivable that some day someone might come up with one but none
exists today.  I have had the opportunity to design such systems for
several cars and have investigated their predecessors.  Torsion bars
belong, if anywhere, in armored vehicles such as tanks, whose armor can
carry the loads at the critical places.

>> a hurry once its vagaries were discovered.
>
> Again you have strayed in the context of the Beetle and the design
> parameters of the Beetle how is the use of torsion bars a poor design.

You probably have no idea what the torsion bars in a Beetle look like.
However, the front bars of both VW's and Porsche 356's all yield the
first time the car hits the bumper pads.  Thereafter they slope forward.

> Sure for what ever race car you may have been building they may not have
> been appropriate but thats not what you have been trying to defended you
> said that the Beetle is poorly design.  So given the previously quoted
> design constraints (from my last post) or perhaps with your connection
> you have access to more accurate statements, why is this a poor design?

I worked on that as well and the Porsche 356 that is a direct
derivative of the VW 411 (Beetle).  How about you telling me what was
good about it.  You are the one who is defending its excellence.  Show
cause.

> not having design anything with a torsion bar suspension I haven't
> examined the design constraints to the obvious depth you have but its
> sound to me that you were maybe pushing limits for this application
> which is a separate issue.  As an engineer surly you realize that what
> will work beautifully in one situation will not always scale or adapt to
> other situations.

They don't work anywhere.  Show me a production car that uses them.

> The execution of the torsion bars suspension on the beetle seems to
> worked quite well. Cheap to manufacture, compact didn't take up as much
> space as leaf spring or coil spring suspension. Do you believe that you
> could build as rugged and dependable system with coil springs that would
> have worked as well in that vehicle?

It was not cheap to manufacture.  That was the main problem with many
of the designs of the VW.  When German labor costs approached those of
competing nations, the high labor content of these designs killed the
car.  Marketing was ready to go for more but there was no way to continue
with these parts perfected through German industriousness.

>> in several designs and was immediately impressed with the expense and
>> difficulty of these springs.
>
> I don't know what expense you are referring. Is it engineering expense
> to adapt it for your usage, production expense because of small
> quantities such a broad unsubstantiated statement.  How does it relate
> to the Beetle.  I have no figures but I have examine the front
> suspension on the Beetle and it looks to me to be a simple well designed
> mechanism that would be easily and economically manufactured and
> installed.

The torsion bars required needle bearing supports in the body,
something that is done by a rubber support in other suspensions.  The
outboard end had double swivel joints, one for each torsion link and
one for steering, on each wheel.  The torsion bar assembly had to be
machined as a unit after welding fabrication to make the bearings run
parallel and square.

> (again I would be Quite interested if you had some facts that refute
> this.  besides the dogma you've been spouting)

What's this "spouting" stuff.  Is that the usual way you discuss matters?

> How is that a poor design constraint?

Cost.

>> It is not "some flaws" but a compendium of flaws in design, some of
>> which were ameliorated by skilled craftsmen who could make these
>> things work.  However, why don't you point to some high points that
>> made the car so great, ones that were not related to the best serviced
>> car and excellent parts supply?  What technical excellence comes to
>> mind?

> Come on its nit picking you presented a lot of interesting agruements
> but they don't substantiate your claim that the Beetle was poorly
> designed.  Mostly what you've presented is dogma and unrelated facts
> that are disguised as an expert opinion.  Big words and jargon to bully
> your opinion through.

I don't hear anything!  Did your dogma eat your homework?

> The basic fact is that for what the beetle was designed for it was
> an excellent execution of design simple, torsion bar suspension, air
> cooled engine, modular chassis.  Simple that makes it cheap reliable
> easy to repair when problems occur.  Problems no worst than many
> higher priced cars of the eras 50's,60's, and 70's.

That is not a fact.  Besides, BioPace was equally successful and
accomplished the same thing in bicycling.  Do you defend it also?

>> I think I have done so extensively.  How about pointing at where
>> you want more supporting evidence or detail.

> See above

Oh oh.  As they say in programming, I think we are in an infinite loop.

>>> There are many "designs in making an automobile that effect the
>>> final product".  Whether it has to do with basic design, the
>>> individual component design, the manufacture design/limitations to
>>> generally say a design is poor you have to do a little more research
>>> than what you have.  Well your hands on experience is certainly a
>>> part of the experience it is in the end a small part in the design
>>> of a complex machine.

>> What are you getting at?  Individual design and complex machine?

> yes

So, what does that mean?

>> I was involved with the design of three different cars while at
>> Porsche.  The 804 F1 car in a small design team in which we were held
>> to tradition, using air cooling, torsion bars, non roll steering rear
>> suspension, although we as a team would have liked to build something
>> else.  The 904 got coil springs and the 911, although saddled with
>> torsion bars got McPherson struts.  I don't know what you mean
>> by "never tried to actually" but I think I have enough experience to
>> comment on designs.
>
> I see where you attitude come from.  My apologies wrt to "never tried to
> actually"  but from the timber of your comments you appeared to be
> unfamiliar with the process.  I still am doubtful about any production
> experience which would be more relevant in this discussion about a mass
> produce vehicle.

How can you judge from what I said whether I was involved in the
process or not?  Besides, you seem to be one who believes an auto
mechanic rather than an engineer.  Better yet, a bike racer knows more
about frame design and fabrication than a frame builder because he can
ride faster.  What sort of credentials do you seek?

>> So what has this to do with designs that are misplaced and known to
>> have problems that have no visible solution?  That air cooling was
>> a pain in the neck was apparent with each of the engines Porsche
>> built.
>
> I would argue that earlier in the development of the automobile that an
> air cooled engine would offer many advantages.  For instances less parts
> less fluids to look after and accomedate in the chassis, less things to
> go wrong, greater reliablity.

You may be surprised but air cooled engines have more and more complex
parts than a water cooled on.  Just consider individual cylinder
barrels and heads to match.  With overhead cams, they have additional
cam boxes and four valve technology is not practical.  Cooling is so
poor that rebuilds are required at unacceptable intervals and oil
management becomes the alter ego of water with an oil cooler that
other cars don't have.

> Know you have to consider that in the context of the operating
> environment.  As I said my father worked on Beetles for many years
> in Saskatchewan Canada and the hot summer and cold winter played
> havic on the engines but if you consider the environmental extremes
> of germany the engine was very well suited.

Oh, I'm sorry that your father got caught between these wheels, but I
understand how you want to defend his choice of car to work on.  The
environmental extremes made it a freezer in the winter and an
overheated in the summer.  Detuned as it was, it just wore out rapidly
instead of blowing up.  Burned valves were a first foot of clay.  The
valve stems on these 1 inch diameter buttons were as fat as those of
valves four times that big elsewhere, to no avail.  The heads got to
hot just the same.

>> VW, with Tony Schmuecker, dodged the air cooling battle long before
>> Porsche had to give it up.

> I suspect these choice were made because of the incresing diverse
> nature of operating perameters VW choose to design for but if we
> consider the orginal Beelte again I have no data but I suspect that
> the orginal design did not include Saskatchewan winters and summers.

The car could no longer be built competitively and the Beetle was no
longer alone in the small car field.  It had to put up or shut up.
The VW company was on the verge of bankruptcy and no more bail out
money was available.

>> The auto industry is not full of idiots who don't recognize that
>> the features in a VW Beetle are superior.  The Beetle was not and
>> only Chevrolet was foolish enough to try to elbow in on a poor
>> concept by going to rear air cooled engine and swing axles in the
>> rear.

> Why do you suppose Chevrolet attempted it in the first place?  I suspect
> that they felt the premise had sum merit.  Wouldn't you?  The swing
> axle( a poor engineering choice) was soon replaced by a " not sure of
> the name but it corrected the jacking problem with a joint at both ends
> of the half shafts"

They made that decision on the same principles for which you admire
the Beetle and did not analyze the significance of their problems.  GM
did lots of things that brought their downfall.  If you follow their
response to liability suits, you see how their management stone walled
the whole car in and effort to not admit they were wrong.  They made
these decisions about five years before... 1955, when VW still looked
like they were the only game in town.

> In the end the later model Corvairs were good handling and generally
> good cars but public opinion was so against them that they couldn't
> recover.  Didn't you make a comment about having no respect for
> people spewing legends perpetuated by the media.  A number of you
> comments seem to fall into this category.

That was retrograde maneuvering from the guys in charge.  The Corvair
lost money all the way out the final door after that debacle.

>> What are you smoking anyway?

You were the one who brought up smoke.  So how about furnishing some
reasons to support your claims.  I'm not going to write the VW and
Porsche history here on this subject for you.  Stop repeating urban
legends.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Torsion bars; was: Re: Using bicycles to introduce mech. engr. 
	topics
Date: 29 Sep 1997 03:54:11 GMT

Mike Kohlbrenner writes:

>> The SUV syndrome will open automotive design to new heights of
>> gratuitous equipment, be that huge knobby tires that never see dirt,
>> gigantic ground clearance, black windows, rumbling multi-pipe exhaust
>> systems and other non functional, non economical features.  I think
>> that falls in the same category as the $200 Nike shoes that must be
>> worn with open laces.

> OK, but what does this have to do with whether or not torsion bar
> springs are valid on this vehicle?  Care to analyize the design
> rather than making judgements on the owners of the vehicles?

Because you are considering a vehicle where image is all and gimmicks
are the routine.  If I took these vehicles as a model, I would have
six inch diameter chrome exhaust pipes on my car.  They must be good,
I saw them on a Jimmy!

> And BTW, Honda also used a torsion bar spring in the front end of
> the Civic.  Why?  Well, since they were using a strut with a coil
> spring, either the geometry would be poor or they would have to
> raise the height of the cowl just for the strut/spring clearance.
> They went to a torsion spring mounted under the chassis and got
> the best of both worlds.

> Why, do you ask, did they stop using it?  Well, they went to a
> double arm front suspension design which meant the shock/spring
> location did not effect geometry so they could implement a coil
> spring without having to raise the cowl height.

The McPherson Strut doesn't like to accept a front drive without a
height penalty.  I am not a fan of front drive for several reasons,
both functional and the way it feels to drive.  It is the most
economical as far as space goes but it costs.  It avoids a front to
rear drive shaft and allows a flat rear floor with no straight through
axle and differential.  CV joints and front end suspension takes it on
the cost chin.  Even big cars, like Cadillac are front drive, which I
think is unfortunate.  They have the space and steering a rear drive
front engine car is more natural.  The complete use of power steering
is supposed to overcome that but I find that in itself a pain in the
neck.  Most people have no feel for what a car with manual steering
is.  Most cars used to be manual until the torque exceeded a
threshold, so that on the highway you had good steering feel but no
load.  That's mostly gone now.

> And why, do you ask, did they move to the double arm suspension
> design?  Well, to get rid of that terribly archaic strut design,
> of course -- yes that's right -- the strut, the tried and true
> front suspension design for decades is suboptimal.  It certainly
> worked quite well for many years and many lauded its brilliance
> as a very simple, cost effective, design.  But the fact is that
> technology has moved on, and the limitations are evident.

I never liked it because it asked too much from a shock absorber.
Because the piston rod carries the car, it is so big that its seals
were a drag and the units don't last as long as a regular shock, but
to make up for that, they cost more than ten times as much.

> I guess now, we can start saying how all of those BMWs are poorly
> engineered because they used struts and now we know better...

> And BTW, aren't the vast majority of anti-roll bars in automobiles
> torsion bar springs?

All. But they are under no load except in curves so they can have
rubber bushings, something that you can't get a way with on a load
bearing joint, because it will extrude under the load.  Rubber creeps.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Torsion bars; was: Re: Using bicycles to introduce mech. engr. 
	topics
Date: 2 Oct 1997 20:07:23 GMT

Doug Milliken writes:

>> The torsion bar has a unidirectional load that is constant while
>> control arms have loads in random directions.  Rubber extrudes
>> plastically under long term unilateral loads.  That is why these

> Jobst -- I believe that your general statement about rubber
> extruding/creeping under constant load needs some more clarification.
> While I'm not a rubber expert, I believe that this must depend on the
> stress and the type of rubber.

The type of rubber used for suspension is the one that creeps and
flows.  Classically, air conditioning pumps are mounted on such rubber
and because the fan belt load is constant, the belt becomes slack and
squeals when the engine accelerates.  The belt is then tightened and
the now sagging pulley of the air conditioning pump runs out of plane
and causes the ubiquitous belt murmur common to many cars.  I cite
this example because it can so readily be observed.  Suspension joints
that suffer this problem are less visible but they creep the same way.

> For example, the springs on the original British Austin Mini (with the
> levered rubber-cone-spring suspension) do not have creep problems.  These
> rubber springs hold up the weight of the car continuously, operating with
> the levers at about a 1:4 lever ratio (spring sees ~4X the force that the
> tire does).  The factory has found samples >10 years old, with perhaps
> 300,000 - 400,000 miles on the car.  When the rubber springs are tested
> they meet the original production specification, ie, no creep or change in
> spring rate.

I am not familiar with these units.  Are you saying the car is
suspended on rubber springs, no steel?  This seems unusual because
rubber has such a relatively low specific energy capacity.

> Perhaps you are generalizing about German rubber <grin>...  In my
> limited experience (60's and 70's VW's) this tended to have a very
> limited life, when compared to rubber parts on cars from other
> countries.

The rubber used in isolating the VW engine and transmission was
another engineering problem that went unsolved.  Because the tracking
of the rear wheels depended on the accurate location of the
transmission, the wheels being guided by axle tubes that articulated
from the case, the location of the box was critical.  Therefore, it
could not be adequately shock mounted or the car would fishtail worse
than it already did, being and oversteering car.  Thus the
transmission, even on Porsches was rigidly attached to the central
chassis that is part of the front end and dashboard.  The engine that
is bolted solidly to the transmission, telegraphed its every
breathing, knocking, sound to the driver.  Porsche used large rubber
mounts that degraded handling so much that they were subsequently
encased in steel cups that rendered them inert, rubber being
incompressible.

> All the VW rubber - wipers, hoses, door gaskets, window surrounds,
> etc, seemed to crack or fail often.  I always wondered if there was
> some "secret ingredient" that the German chemists didn't know about
> or couldn't get.

The Trico or Anco replacements didn't last much longer.  The wiper
mechanism was mainly at fault because it requires a stiff blade unlike
the well sprung wipers that work.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: drela@mit.edu (Mark Drela)
Newsgroups: rec.bicycles.tech
Subject: Re: Torsion bars; was: Re: Using bicycles to introduce mech. engr. 
	topics
Date: 2 Oct 1997 22:57:26 GMT

In article <610utr$42g@hplms2.hpl.hp.com>, jbrandt@hpl.hp.com (Jobst
Brandt) writes:

> I am not familiar with these units.  Are you saying the car is
> suspended on rubber springs, no steel?  This seems unusual because
> rubber has such a relatively low specific energy capacity.

I don't know what kind of rubber you are referring to,
but pure gum rubber can store more than 10000 J/kg
of strain energy.  This is about 20 x more than steel
with a 200 ksi ultimate.  I'm sure even synthetic rubber
with carbon black and other fillers blows away any metal
in this regard.

                   Mark Drela
             _______________________________
    o/LO  .'
     O  .'  Gravity-Powered Technologies Lab
      .'  MIT Aero-Astro Department  37-475
     '

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Torsion bars; was: Re: Using bicycles to introduce mech. engr. 
	topics
Date: 3 Oct 1997 02:18:55 GMT

Matt O'Toole writes:

>> The type of rubber used for suspension is the one that creeps and
>> flows.  Classically, air conditioning pumps are mounted on such
>> rubber and because the fan belt load is constant, the belt becomes
>> slack and squeals when the engine accelerates.  The belt is then
>> tightened and the now sagging pulley of the air conditioning pump
>> runs out of plane and causes the ubiquitous belt murmur common to
>> many cars.  I cite this example because it can so readily be
>> observed.  Suspension joints that suffer this problem are less
>> visible but they creep the same way.

> I've often wondered about this one.  The problem always seemed
> obvious to me.  It's good to hear my suspicions confirmed by an
> automotive engineer.  So, why do they still use the damned things?
> GM cars in particular seem to always have noisy belts.

Because they've always done it that way and so do the others, Volvo
is no exception.  They're jerks.

> The Mini had a bumper suspension, like a simple elastomer bicycle
> fork.  The rubber bumper served as both the spring and damper.  I
> find it hard to believe that kind service life is typical, though.
> There are enough agents in the air and being splashed up from the
> road that could cause the rubber to deteriorate.

Then in so many words, it used the tires as springs and the rubber
as a large progressive bumper.  I suppose that would work if you
wanted to do it on the cheap.  That doesn't ask much from the rubber.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: Pete Albrecht
Newsgroups: rec.crafts.metalworking
Subject: Re: Those who KNOW use anti-sieze
Date: 30 Oct 1997 07:14:30 GMT

The Global Village Idiot, altavoz, had to dazzle us with his self-perceived
 brilliance re automotive suspensions:

>>No , tell it to 911 Porsche DUMB SHIT !!!!! Mac takes up much more room than
>> Porsche ( they use Tor'  bars) !! IDIOT

Idiot and dumb shit yourself.
1) Porsche 911 has always had MacPherson struts at the front. Still does. They
 got rid of front torsion bars more than 33 years ago when they phased out the
 all-torsion-bar 356.
2) Porsche no longer uses torsion bars on any of their cars, not even at the
 rear of the 911.
3) The rear of the 911 (Type 993, internally) has had MacPherson struts (or
 Chapman struts in this case, if they're at the back) since late 1994.

Torsion bars have a few advantages but many more disadvantages. For example,
 the village idiot's statement that ride height is easily adjustable could only
 have been made by somebody who never had to adjust ride height at the back of
 a torsion-bar Porsche or VW. I could list other drawbacks but I doubt if it
 would do any good, what passes for a brain in Altadipshit has already been
 made up.

>> Your last 3 sentences are incoherent .

Altaidiot, your LIFE is incoherent.

Pete Albrecht
former Porsche engineer
present Porsche owner, torsion bars and all

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Plain, Anodized or ceramic coated rims??? (WARNING--NON-BIKE STUFF 
	THIS POST)
Date: 31 Mar 1999 18:14:09 GMT

Tim Smith writes:

>> This is similar to the popularity of the air cooled car in the 1950's
>> when people remembered boiling radiators of pre WWII vintage.  What
>> they didn't notice is that the military perfected the water pump seal
>> during the war and post war cars didn't boil over anymore, yet one of
>> the main sales points was originally "-air cooling-",... something no
>> car should have anyway.

> Popularity? So how many air-cooled cars were ever on-sale in the US?
> Three, maybe? VW, Porsche, and the car-that-never-should-have-been:
> the Corvair.

The desire for air cooling in cars was always driven by a loathing for
geysers at the radiator (convection heat exchanger) or blowing out a
hose.  What went unnoticed was the cause even to the bitter end of air
cooled cars, and that was the pump seal.  That Porsche had air cooling
came from the name or its heritage.  If Ferdinand Porsche designed it
(and he didn't) then it must be right.  That is why the Porsche had a
rear engine and torsion bars, two other anomalies not seen on cars.
That Corvair imitated the VW was a belated "me too" attempt and I
think the man responsible for that one should have been fired for the
many failings of that car that were previously known for other
attempts.

> Don't remember that VW ever tried to make a marketing/advertising
> point of the lack of liquid--perhaps they did.

That was a major part of the initial sales pitch.  With a car so
different, Madison Avenue had a field day coming up with wacky ads
that made features of many of the failings of the car.  They
advertised how easy it was to remove the engine... it needed it.  VW
shops always had engines standing around for one repair or another.

> I always thought that it was "not there" as a  simplicity/cost-cutting
> measure in the peoples' car (water pumps, radiators, liquid,
> weight).  Interesting that the other European rear engine cars of
> the 50s (Fiat 600s, Renault 4CVs, and their ilk) were water-cooled
> (barely, in the 4CV case).

That was the pitch but it isn't cheaper at all.  The motor block is
made of two halves and four cylinder barrels whose thermal expansion
is a major failing of the engine.  Besides, it is partly oil cooled,
having an oil cooler that sits inside the fan housing.  This oil
cooler blocks air from reaching the left front cylinder and the air it
gets is pre-heated by the oil cooler.  Hence, burned valves and scored
cylinders in CYL-3.  The litany of blunders in that engine is lengthy.

> But you've been there, and would know the reason for it. I'm not so
> sure it was marketing, but enlighten those of us who suffered 1950s
> cars with more info.

The VW is the perfect vehicle to teach automotive designers what not
to do.  It has inappropriate concepts from the tip of the front bumper
to the rear one.  What made the car what it achieved was a dedicated
staff and a great service network with a nation of eager workers who
believed in their product.  What they didn't have in the product they
had doubly in commitment at a time when the US auto industry was smug
in having won the war.  Let them eat cake! was their motto.

Jobst Brandt      <jbrandt@hpl.hp.com>

From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: Tie and Solder Revisited
Date: 13 Sep 2000 21:28:51 GMT

Mark Hickey writes:

> As far as the T&S'd wheels - if you need to do a true blind test,
> simply wrap string around the "non-T&S'd" wheels, and put a dab of
> opaque glue on each.  Now they're identical in appearance.

Let me suggest using two sets of wheels, both of which have the spoke
crossings covered with electrical tape so that what is or is not on
the spoke crossing cannot be seen.  Then you could do as was done with
CEO Nordhoff, who said anti-sway bars made no improvement in handling
of the VW beetle.  One car had no anti-sway bar, the other did, except
tht it was disabled by a saw cut through its center.  Nordhoff knew
where to look in the wheel well to detect the presence of the
anti-sway bar and promptly said after test driving that the car
handled more poorly.  No one mentioned the circumstances to him but
from then on he was not invited to comment on comparative hndling or
much of anything else developed in the lab.  So much for testing with
non believers.  You gotta be careful, they cheat.

Jobst Brandt      <jbrandt@hpl.hp.com>