Why do fat tires offer better grip on the road than thin tires? *SOLVED*

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And don't say it's because it has more surface area. If you've done some basic studying in physics of friction you'll know that if you are pushing something like a brick on its flat side it will be exactly as difficult to push it when it's on its small end. The reason being that the friction coefficient is equal and, although there is less surface area, the increase in weight between the brick and surface it's on means that it's the same difficulty in both cases.

So, why do wider tires work so much better than thin ones? My guess is because there are small "rips" occuring on the tire surface when torque is acted against it, and in wider tires there is more riping going on than on the small ones. Although a tire two feet wide vs. a tire one foot wide will have half the pressure at any square inch between itself and the ground presumably the ripping will occur at more than half the rate, thus allowing greater traction.

*SOLVED* You can read the thread for a couple of different ways that fat tires are more effective than thin, and if you're like most everybody else here no you do not know the answer yet even if you think you do

 

It has more surface area, your analogy does not work with rolling traction Skoorb.

 

[DurocShark]

It's the side-to-side torque that's affected. In a straight line, there's no difference (other than rolling resistance).

 

[StageLeft]

Originally posted by: Roger
It has more surface area, your analogy does not work with rolling traction Skoorb.

But with kinetic friction the same equation applies for the brick as it does when the brick is not moving (static friction).

 

[StageLeft]

Originally posted by: DurocShark
It's the side-to-side torque that's affected. In a straight line, there's no difference (other than rolling resistance).

Well then why do drag cars have fat ass tires?

 

What ever Skoorb, think what you want

 

[Amused]

Skoorb, put bicycle tires on your Nissan and see if it has the same traction.

 

[vi edit]

I think this largely depends on surfaces and weather conditions. As well as tire compounds and tread patterns.

You can't compare them apples to apples otherwise.

 

[StageLeft]

Originally posted by: Roger
What ever Skoorb, think what you want

It's true! The force required to move something when it's not moving is: f = uF where f is force required, u is the coefficient of friction, F is the normal force (force of gravity pulling it down). The equation is the same (actually I just gave the kinetic equation - static is a touch different but irrelevant to this) for a moving object except in that case f is the force required to keep the object in motion, and when something is moving u (kinetic friction now) is likely to be lower than static friction.

So I still have no answer!

 

[spidey07]

surface area

 

[StageLeft]

Originally posted by: Amused
Skoorb, put bicycle tires on your Nissan and see if it has the same traction.

I'm not denying the fact that wider tires help; I merely want to know WHY they help - since that equation I provided doesn't indicate that they would.

 

It's true! The force required to move something when it's not moving is: f = uF where f is force required, u is the coefficient of friction, F is the normal force (force of gravity pulling it down). The equation is the same for a moving object except in that case f is the force required to keep the object in motion, and when something is moving u (kinetic friction now) is likely to be lower than static friction.

Fine Skoorb, equate this ;

4,000 lb vehicle

Use your equation to figure out the coefeciant of friction with :

2 inch wide tire

4 inch wide tire

6 inch wide tire

Show me that they all come out with the same friction.

 

[DuallyX]

Fat Tire= GOOD BEER!

 

[dxkj]

Do skinny tires break free easier or harder than fat tires?

 

[deerslayer]

Originally posted by: Skoorb

Originally posted by: DurocShark
It's the side-to-side torque that's affected. In a straight line, there's no difference (other than rolling resistance).

Well then why do drag cars have fat ass tires?

Because the wider they are, the more track they grip. Can you imagine putting all that torque that is produced behind a set of skinny little tires?

 

[Rkonster]

http://www.physlink.com/Education/AskExperts/ae200.cfm

 

Do skinny tires break free easier or harder than fat tires?

I assume you mean how they release, either abruptly or gradually, tire compound and hieght of sidewalls decide this, not tire width.

 

[Viper GTS]

Originally posted by: Roger

It's true! The force required to move something when it's not moving is: f = uF where f is force required, u is the coefficient of friction, F is the normal force (force of gravity pulling it down). The equation is the same for a moving object except in that case f is the force required to keep the object in motion, and when something is moving u (kinetic friction now) is likely to be lower than static friction.

Fine Skoorb, equate this ;

4,000 lb vehicle

Use your equation to figure out the coefeciant of friction with :

2 inch wide tire

4 inch wide tire

6 inch wide tire

Show me that they all come out with the same friction.

He is correct, assuming the same compounds they would have the same frictional coefficient.

Viper GTS

 

[StageLeft]

Originally posted by: deerslayer

Originally posted by: Skoorb

Originally posted by: DurocShark
It's the side-to-side torque that's affected. In a straight line, there's no difference (other than rolling resistance).

Well then why do drag cars have fat ass tires?

Because the wider they are, the more track they grip. Can you imagine putting all that torque that is produced behind a set of skinny little tires?

I know that wider tires have more grip. But I still don't know WHY. The equation I used is sound and states that they will not. So obviously there is something else acting here that I'm not aware of.

4,000 lb vehicle

Use your equation to figure out the coefeciant of friction with :

2 inch wide tire

4 inch wide tire

6 inch wide tire

Show me that they all come out with the same friction.

Well the weight of the vehicle and the width of the tires has nothing to do with the coefficient of friction (at least based on this equation). It will surely be the same between all tires, since they are all of the same material.

In fact if I had to guess it could be a BIT higher on the 2 inch wide than the 4, and in turn than the 6, because the increased pressure per square inch of the contact surface will push the imperfections of the tire futher down into the imperfections of the road (kind of locking them together).

 

[dxkj]

NM my above post, I know the answer to this question but Im not sure how to express it, give me a few mins to think

 

[StageLeft]

Originally posted by: Rkonster
http://www.physlink.com/Education/AskExperts/ae200.cfm

Ah thank you!!!!!!!

 

[klod]

From PhysicsLink.com:

Friction is proportional to the normal force of the asphalt acting upon the car tires. This force is simply equal to the weight which is distributed to each tire when the car is on level ground. Force can be stated as Pressure X Area. For a wide tire, the area is large but the force per unit area is small and vice versa. The force of friction is therefore the same whether the tire is wide or not. However, asphalt is not a uniform surface. Even with steamrollers to flatten the asphalt, the surface is still somewhat irregular, especially over the with of a tire. Drag racers can therefore increase the probability or likelihood of making contact with the road by using a wider tire.
Answered by: Stephen Scholla, B.A., Physics Teacher, Vienna, Virginia

 

Wrong, you will not get increased traction because the tire is smaller in width, why ?
After a certain point, the rubber compound does not gain any increase in traction if you apply more wieght on it, the rubber deforms causing pockets to form between the carcass and ground causing less friction.

Skoorb

You are not considering tire deformation under load.

 

[dxkj]

Originally posted by: Skoorb

Originally posted by: deerslayer

Originally posted by: Skoorb

Originally posted by: DurocShark
It's the side-to-side torque that's affected. In a straight line, there's no difference (other than rolling resistance).

Well then why do drag cars have fat ass tires?

Because the wider they are, the more track they grip. Can you imagine putting all that torque that is produced behind a set of skinny little tires?

I know that wider tires have more grip. But I still don't know WHY. The equation I used is sound and states that they will not. So obviously there is something else acting here that I'm not aware of.

4,000 lb vehicle

Use your equation to figure out the coefeciant of friction with :

2 inch wide tire

4 inch wide tire

6 inch wide tire

Show me that they all come out with the same friction.

Well the weight of the vehicle and the width of the tires has nothing to do with the coefficient of friction (at least based on this equation). It will surely be the same between all tires, since they are all of the same material.

In fact if I had to guess it could be a BIT higher on the 2 inch wide than the 4, and in turn than the 6, because the increased pressure per square inch of the contact surface will push the imperfections of the tire futher down into the imperfections of the road (kind of locking them together).

I was thinking the same thing.... but i dont think the skinny tire could take that kind of pressure and not get torn up, etc. So thats why you use fatter tires

 

[StageLeft]

Actually I was wrong in the case of the 2 inch if their coefficient is .30 with the 4 inch it will be .15 and the 6 inch would be .10 That way with the same normal force the same forward pressing force will be required.