Does friction have anything to do with the width of a race car's wheels?

Question

friction has to do with traction, and obviously, a drag racer with big back wheels desires traction, but if you look at the friction formula, no where in the formula does it require the surface area or any area at all, so why is a dragrace car's tires so much bigger than normal?

f = μN, where μ is the coefficient of friction, N is the force normal to the contact surface, and Ff is the force exerted by friction.

Answer 1

WOW... WOoooWW...

How come nobody has said anything about the fact that drag racers have extremely DEFLATED TIRES?

Because you're right, dude who asked the question, the smaller the surface area, the more friction is applied. However, when it comes to drag racers, they also deflate the tires, making them more 'coarse', if you will. Ever rode a boke with flat wheels? Ya, it sucks because you're not riding on much air, one, and two the tire forms to the surface a lot better. Kind of like a ghecko's feet (how do they stick to glass?... they have extremely small cells that seep into tiny cracks in glass = like deflated rubber into a pavement).

Ideally, no matter how heavy an object is, if the surface friction is zero, then it will be moved just as easy as an extremely light object. However, in the real world, friction not only depends on area of application, but also on other things.

Answer 2

Well, there is quite a lot going on with a wheel on the road.

First of all, when acceleration is applied, the tire will tend to slip on the surface resulting in a loss of energy. This energy has to go somewhere and it does, it heats up the tire. You can see this if you accelerate very hard and produce clouds of smoke! Now, the amount of energy that gets converted to heat will depend upon the coefficient of friction and load but not the surface area. If the surface area is very small, the tire melts very quickly and bursts. If the surface area is large, the heat is spread over a larger area and the tire will not melt and burst.

As it rotates, the tire is continually deforming (bending). This generates heat which needs to be dissipated and is done better with a large tire than a small one.

As a matter of interest, the continual deforming of a tire eats up an huge amount of energy and accounts for most of the energy required to move a car at speed. This is why metal wheels running on metal rails are more efficient. The low profile tires that you see on some sporty models of car reduce the amount of energy lost through deformation of the tire.

Answer 3

This friction formula is just an approximation that gives fairly good results, but it is not always correct.
Larger surface area normally gives larger friction force, but I don't think there is a universal friction formula that works for all material, so you might as well use the one you have. Only use it with caution.

Answer 4

Because the engine is so much bigger, too, and that is a bigger factor than the increase in drag.

A dragster's performance with skinny little tires would be to burn the rubber and blow out the tires. All that power has to be distribued over such a tiny "contact patch" (the amount of rubber than actually touches road surface) that it would all get hot and burn up unless the tires were very large.

The cars that get great gas mileage tend to have thin tires. The cars that handle well or accelerate fast tend to have large, broad tires.

Answer 5

there is extensive discussion about this question here:

http://www.madsci.org/posts/archives/oct98/908313145.Ph.r.html

I think they are missing the point of the explanation as to how the area cancels out in pure simple examples

they give good examples about how real applications, such as racing car wheels, have many unsimple things going on that benefit from the wider wheels (tire deformation, heat removal, non-smooth road surface, etc)

the area does affect the total friction, just not the friction per unit area, which is how the normal force is applied

if you have twice as much area and twice as much weight, then you get twice as much friction

if you have twice as much area, but only the same amount of weight, you get half the normal force and twice the surface yielding the same final "frictional force"

Answer 6

You are either looking at the wrong formula or you are
doing something else wrong..
The weight of the car, the co-efficient of friction between the
tire and the track and the amount of contact area should all
be in the formula..
This obviously takes into account the width of the tire..

Answer 7

The wider the tire the more rolling resistance it will have. A skinny tire will roll a lot more easily than a fat tire will. Now, the skinny tire will not have nearly as much traction, or grip on the road as a wide slick racing tire. The contact patch (the amount of tire actually on the ground) is what traction is based upon.

Hope this helps out.

As far as a fomula goes, you are on your own on that one.....

Stevo.

Answer 8

Hmm, if it relatively is been you dream for the final 15 years when you consider which you have been 4 to be a nascar driving force; that could make you 19 years previous and you does not would desire to ask your Dad. howdy i had to be a nascar driving force this morning , yet have been given talked out of it. best of luck nevertheless.

Answer 9

Common sense says it should make a difference. Maybe you have the wrong formula?