From: jobst.brandt@stanfordalumni.org
Subject: Re: Repost: tire rotation direction?
Newsgroups: rec.bicycles.tech
Date: Sun, 16 Sep 2001 04:41:00 GMT

Van Bagnol writes:

>> I would like to repost this question as I did not get any
>> responses.  After reviewing Sheldon Brown's site I believe that the
>> correct answer is "NO" it does not matter which way the tire tread
>> pattern faces but I am still unsure.

> I think the general rule of thumb for mountain bike tread patterns is
> that the "V" should point in the direction of rotation for the front
> tire, but opposite the direction of rotation for the rear tire (as
> evidenced by treads on tractors). Rear tires, however, typically have a
> "ladder" tread rather than a "V" tread.

Tractor treads are intended to dig but cleanse themselves by pushing
soil to the side as they 'spin' in soft terrain.  This occurs only if
the chevrons of the tread slide pointed end first.  Therefore, I think
you have the directional notation reversed.  However, all this does
not effect bicycles because they do not dig in wheel slip mode as a
tractor.  This analogy is as out of place as the acceleration of
rotating mass in wheels, because on a bicycle there is no net long
term acceleration.  Likewise there is no long term wheel slip as on a
farm tractor.  Bicycles don't sit in place and dig.

Let's use a rule of thumb or a general rule, but not both.

Jobst Brandt    <jobst.brandt@stanfordalumni.org>

From: jobst.brandt@stanfordalumni.org
Subject: Re: Continental Top Touring 2000 Tires - Mounting Direction Question
Newsgroups: rec.bicycles.tech
Message-ID: <ug32e.12539$m31.128272@typhoon.sonic.net>
Date: Tue, 29 Mar 2005 02:42:34 GMT

George Karabotsos writes:

> I bought two Contis Top Touring 2000 tires and I have a question on
> the direction I should mount them on the rims.  On the left side of
> the tire there is the following inscription: REAR WHEEL <-- | -->
> FRONT WHEEL.

> In other words there is an arrow pointing counter-clockwise to the
> right of "REAR WHEEL" and another arrow pointing clockwise to the
> left of the "FRONT WHEEL".

> Now to the question: What does this mean?  Does it mean I have to
> mount them on the direction of the arrow based upon which wheel I
> place the tire?  I know it seems obvious, but I just want to make
> sure.  This is the first time I have seen such a tire inscription.

Just forget the whole thing.  This is a gimmick of the tire folks who
introduce this concept at various times.  That agricultural tractor
tires have a preferred direction of the chevrons is clear.  It only
has an effect if the tractor spins its wheels in soft dirt where
orientation of the V-shaped tread helps clear soil from the tread by
the chevrons digging point first.

Directional tread was touted for motorcycles about 30 years ago, cars
have done it recently with V-shaped "water displacement" grooves, so
bicycles have picked that up, not to be left behind in a good ploy.
It has no beneficial effects on cars according to independent test
done by Auto Motor & Sport magazine, and because I followed that when
motorcycles did it, I am sure it has no effect on bicycles either.

Jobst.Brandt@stanfordalumni.org