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From: jbrandt@hpl.hp.com (Jobst Brandt)
Subject: Re: Why knee probs. with clipless pedals?
Date: Wed, 6 Sep 1995 16:59:29 GMT

Jesse Sheidlower writes:

> With the toe straps tightened down--i.e. most of the time I'm
> riding--my feet are locked into my pedals far more rigidly than with
> any clipless pedal: there's no rotational movement at all, and you
> can't even get your foot out without loosening the toe strap. So why
> on earth would a clipless system, with various amounts of
> flexibility and movement built in, be _more_ prone to any sort of
> pain? 

There are many people who have taken up bicycling and have bad knees
anyway today than in the past.  Formerly anything more than a slow
jaunt down a city street was done only by the athletically inclined.
Today many people who had little exercise take up bicycling for health
and run into their various frailties. They would not do well with the
cleat and strap system either.

Bicycling is an unusual exercise for most people because articulating
the knee under load seldom occurs otherwise.  Even climbing stairs
involves only a six inch rise instead of a rise more than twice that
on a bicycle.  It was not all that long ago that the US military
discovered they were producing a large number of 4F (physical fitness
failures) by their "squat jump" exercise that was subsequently
deleted.  Bending the knee under load is not acceptable to the knees
of many people, and no manner of pedal rotation or high RPM pedaling
will materially help them.

Jobst Brandt      <jbrandt@hpl.hp.com> 


From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.racing
Subject: Re: Keep knees covered in cold weather
Date: 7 Jan 1999 23:14:47 GMT

Gil Ormerod writes:

> Back in the 60s I had an ex-German national team member for a coach.
> He insisted that his riders all keep their knees covered until it
> was at least 70 degrees.  He stated that the cold air on the knees
> would lead to knee problems.

Likewise Eddy B (Borysevitch) had admonitions and rules, some of which
were generally applicable and others not.  I don't believe all riders
have knees that are as sensitive to cold as the 70 deg rule implies.
I have watched and read about many pro cyclocross races in the snow
with riders in shorts.  I ride in freezing weather with exposed knees
with no problem.  It's the cold feet and hands that bother me.

> I was riding the other day in 45 degree weather and saw another
> cyclist doing hill repeats on this chilly but sunny day wearing
> shorts, no knee or leg coverings.  It got me thinking... I usually
> keep my knees covered until about 60 or 65 degrees (sorry Werner!),
> but I'm not sure if it really matters.

I don't think you can deduce that the rider is damaging something just
from the temperature.  I have ridden in cold weather with no knee
protection for many years without ill effect.  In fact on most of my
Alpine tours, I have often encountered snow and cold on the higher
mountain passes in July.  The Iseran, Stelvio, Bonette and Gross
Glockner come to mind most readily.

> Does anybody have any scientific or medical reasons to support what
> the temperature should be before you uncover those knees?

I'm sure there are people who do not do well in cold weather but
probably just as many who do.  I fear that any blanket pronouncement
may lead to some ritual of correctness of which bicyclists have too
many already.  I already meet too many riders advise me that I will
soon be an invalid because I don't spin enough, wear enough clothes,
don't have the right tires to ride in the woods, need more gears and a
slew of other things that they know of from such strictures about
which they read somewhere.

Jobst Brandt      <jbrandt@hpl.hp.com>



From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: What is a good cadence?
Date: 15 Apr 1999 21:21:39 GMT

John Verheul writes:

> Cycling hard on knees? What does this guy do when he has to walk up
> or down any stairs, crawl? How macho is that?

As I have often mentioned, bicycling is like taking two stair steps at
a time, and then some.  Standard stairs have a six inch rise, a
bicycle has about 13.5 rise.  People who start riding bicycles late in
life (post teen) are often in trouble because their joints have not
articulated that far under load in ages.

Unfortunately these oldsters make up the majority of riders and they
all know that what's good for them is good for you.  Not only that,
most are not aware of what effect they are trying to ameliorate with
their preoccupation with RPM.  They often advise me on how to ride a
bicycle, being oblivious to the obvious age and use of my bicycle and
that I know how to ride it.  They'll tell me of the dangers of riding
no hands as I occasionally do, dodging holes in the road, while they
are too busy with their tutorial to avoid them themselves... and some
wonder why my patience gets thin at times.

Jobst Brandt      <jbrandt@hpl.hp.com>



From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech
Subject: Re: What is a good cadence?
Date: 16 Apr 1999 01:41:58 GMT

David T. Blake writes:

>>> Cycling hard on knees? What does this guy do when he has to walk up
>>> or down any stairs, crawl? How macho is that?

>> As I have often mentioned, bicycling is like taking two stair steps
>> at a time, and then some.  Standard stairs have a six inch rise, a
>> bicycle has about 13.5 rise.

> Right.

> But in bicycling, the load is pseudo-sinusoidal with a peak in the
> center of the range of movement. The rider can use gears to achieve a
> suitable load for a given grade.

I think you'll find that climbing hills, the leg force is applied as
soon as the pedal comes over TDC, the duty cycle being longer than in
the flats to avoid "roll-back" pulsation in motion.  Although riders
claim they spin up hills, these people are riding in such a low gear
that they are climbing far below their ability and are optionally
going slower.  This is usually what I observe when on a rare occasion
I come across a recumbent going up hill.

> In climbing stairs two at a time, the loads are peak at the beginning
> of the step while the knee is fully flexed. The load is fixed at the
> (usually) overly heavy weight of the climber.

It took the military many years to discover that the "squat-jump"
exercise was giving them the most physical discharges from service.
It's probably a good destructive test of who is and who is not a good
bicycling prospect.

> These factors mean that a somewhat experienced cyclist could have no
> problem with his knees on the bike, but large difficulty in climbing
> stairs two at a time.

As I said, I don't think they are as far apart as you suggest, because
power on the flat is applied during a different part of the stroke
than climbing.  Next time you're out on a hill, have another look at
it.

Jobst Brandt      <jbrandt@hpl.hp.com>


From: jbrandt@hpl.hp.com (Jobst Brandt)
Newsgroups: rec.bicycles.tech,rec.bicycles.racing
Subject: Re: another knee soreness question (please help)
Date: 15 Aug 2000 01:04:29 GMT

Dan Carwin writes:

> I've increased my weekly mileage significantly in the last few months,
> having taken delivery of my new custom bike, and my legs are generally
> fine, but I am getting some knee soreness as I ride on longer rides
> and after.

> The soreness is right above both kneecaps, in the area between the
> kneecap and the start of the main (quad?) muscle. This is in the
> front, and on the top.

That's the spot and it is common for folks who did not ride between
the 8th grade and later in life.  The cause is atrophied ligaments
that have not been operated under load with that large a stroke.  The
most that people generally do is climb stairs and stairs have a rise
of a bit over 6 inches per step. Bicycles have a step height from
bottom to top, the equivalent of stepping of on stair and loading the
other foot, of about 13.8 inches, more than taking a stairway two
steps at a time.  Even a Stairmaster doesn't do that.

> (I wouldn't think so) I run the saddle as high as I think it should be
> without hip rocking. Is it a saddle front-to-back question? Saddle
> tilt?

It's a knee problem.  You hips should not swivel when riding or you'll
have other problems.  You might try shorter cranks.  They are
available but they aren't much shorter.

> The change to a road bike, longer rides and higher gears has probably
> triggered the condition.  I only started to get knee pain when I began
> 60-70 mile Sunday rides."

> Is this my problem?

> All replies appreciated, please cc me via email if you can.

Your knees don't like to ride bike but if you are careful, you might
be able to get them up to snuff if you don't ride as far but ride
faster.  Just enough to get exercise but not wear out what's happening
to the sheaths around your tendons.  There are no short cuts.

Jobst Brandt      <jbrandt@hpl.hp.com>

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