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Posting-Version: version B 2.10.2 9/18/84; site gatech.UUCP
Path: utzoo!linus!decvax!harpo!whuxlm!akgua!gatech!mark
From: mark@gatech.UUCP (Mark Johnson)
Newsgroups: net.auto
Subject: Re: HOW TO TIRE safely
Message-ID: <10677@gatech.UUCP>
Date: Tue, 6-Nov-84 10:47:42 EST
Article-I.D.: gatech.10677
Posted: Tue Nov  6 10:47:42 1984
Date-Received: Thu, 8-Nov-84 07:17:01 EST
References: <501@houxl.UUCP> <456@aluxe.UUCP> <10575@gatech.UUCP> <477@aluxe.UUCP>
Organization: School of ICS, Georgia Institute of Technology, Atlanta
Lines: 31

> > > Oversized tires REDUCE traction since the lower pressure on the road
> > > prevents the tire from conforming to the roughness of the road
> > > and 'gripping' the surface.  
> > I'm sorry but I disagree. If the inflation pressures are equal then the
> > size of the contact patch will be the same regardless of tire width!
> 
> 
> ****                                                                 ****
> From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh
> 
> I would agree if we were talking about innertubes or some soft
> compliant tire, but the radials that are put on the road today
> are claimed to have flat footprints and provide more traction.
> That is due to the rigidity of the steel belts.  If the tread width was
> too wide, the tire would act like a snow ski.  Try using your shoe
> as a crosscountry ski and you will find that area affects traction.
> If you don't want the leg on a tripod to slip you put a sharp
> point on it rather than increase its footprint.

You missed the point. Inflation pressure is by far the biggest factor in
determining contact patch size. The shape of the contact patch will vary, but 
the size will not. One reason modern radial tires are "better" than bias-ply
tires is they are MORE COMPLIANT. 
-- 
Mark Johnson

(404) 894-2746 		(404) 894-3152 

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