ease of skidding on two different bikes

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10-20-07 | 07:31 PM

#26

ersatz radio

Senior Member

Joined: Nov 2005

Posts: 152

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From: Lawrence

Bikes: 1994 Paramount conversion

Quote:

Originally Posted by chase.

this part is true. friction force is determined by the relevant coefficient of friction and the surface area (contact patch) involved; on pavement or other smooth surface your maximum contact patch will be on a fat slick with medium air pressure. knobbies prevent the full surface of the tire from touching the ground, thereby reducing available frictional force.

This is wrong. Surface area has nothing to do with friction. The only relevant variables are the coefficient of friction and the normal force. Wider and knobbier tires can have more traction, but this is either due to the tread mechanically interacting with the road surface or adhesion of the rubber. With a typical road bike tire, neither of these is a real consideration.

edit: Also, the contact area varies very little with regard to tire size. For a slick tire, the contact area is the weight of the bike/rider divided by the tire pressure.

Last edited by ersatz radio; 10-20-07 at 07:45 PM. Reason: no double post

10-29-07 | 08:54 PM

#27

levity

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robot ninja monkey yogi

Joined: Jan 2005

Posts: 89

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From: Manhattan

i know y'all are dying to hear about how things are going with this, so here's an update: i got the 28mm tires (continental grand prix). they're great. they definitely make some difference in the feel of the skid -- it's much smoother. so the longer stem made it easier to start a skid, but the narrower tires make it easier to hold one.