Tire shaving to fight premature camber wear?

[Repoman]

For the most part we as X owners are plagued by premature wearing of the rear tires on the inside. I was tooling around on the net and read about tire shaving. It mentioned that tires can be shaved to fit a particular camber setting for longer wear. Idea is that the tire is always riding on the entire tread instead of more weight focused on the inner edge.

Anyone heard of or have any experience with this? I just got a new set of cheap tires for the rears so I might consider as this set is as good any to experiment with.

[mywidebody02]

that is for race cars not street cars.

[X5 Meister]

Which Gillette would you use for that? The Fusion?

[JCL]

Originally Posted by Repoman

Idea is that the tire is always riding on the entire tread instead of more weight focused on the inner edge.

Why would an inflated tire have any more weight on one edge than the other? Unless you found a way to have a higher air pressure on the inner edge than the outer edge, you will have the same pressure throughout the tire. That means that the ground is pressing up with the same pressure the air is pressing down with, as the sidewall impacts will be minimal.

The tires may deflect more on the inner edge, but they certainly don't have any more load on them.

[Repoman]

Originally Posted by X5 Meister

Which Gillette would you use for that? The Fusion?

Keep going . . . you're almost up to 3900.

You're only a few worthless posts away from the next century mark.

You have helped me to find all kinds of applications for the smilies . . . all in good fun of course.

[Fraser]

Originally Posted by Repoman

For the most part we as X owners are plagued by premature wearing of the rear tires on the inside.

Only if you have the Sport package and don't drive hard enough. Get you boot into it, that will even up the wear..

[Repoman]

Originally Posted by JCL

Why would an inflated tire have any more weight on one edge than the other? Unless you found a way to have a higher air pressure on the inner edge than the outer edge, you will have the same pressure throughout the tire. That means that the ground is pressing up with the same pressure the air is pressing down with, as the sidewall impacts will be minimal.

The tires may deflect more on the inner edge, but they certainly don't have any more load on them.

I disagree but I think we're talking about 2 different things. I'm talking about pressure against the ground, not air pressure in the tire. More pressure against the ground on the inside of the tire b/c/o camber equals faster tire wear at that site. Shaving the tire consistent with the camber angle would place equal pressure across the entire tread which would allow the tire to wear evenly.

Racers do shave their tires for a several reasons. A few are for the same reason I mentioned in the previous paragraph to promote even tire wear in negative camber suspension setups for longer tire life and for better traction, even pressure against the ground across the tread.

I'm looking into it solely for the purpose of extending tire life. Replacing rear tires every 14-15K at $500 a set is bordering rediculous. I already spend enough money replacing prematurely failing parts on the X as it is. I have already straightened up the rear tires as much as BMW will let me and still inside wear. Shaving might be worth a try . . . it can't be any worse.

[JCL]

Originally Posted by Repoman

I disagree but I think we're talking about 2 different things. I'm talking about pressure against the ground, not air pressure in the tire. More pressure against the ground on the inside of the tire b/c/o camber equals faster tire wear at that site. Shaving the tire consistent with the camber angle would place equal pressure across the entire tread which would allow the tire to wear evenly.

No, we're talking the same thing. Air pressure inside the tire equals the pressure against the ground. Your concept of more ground pressure due to the camber would only be correct if you had a solid tire. You don't, you have an inflated tire. It deforms to match the ground.

This is a simplistic view, as we aren't considering dynamics, only statics. However, the theory works. Your camber isn't what is causing the wear on the inner edge, as has been pointed out in other threads.

[Repoman]

Originally Posted by JCL

No, we're talking the same thing. Air pressure inside the tire equals the pressure against the ground. Your concept of more ground pressure due to the camber would only be correct if you had a solid tire. You don't, you have an inflated tire. It deforms to match the ground.

This is a simplistic view, as we aren't considering dynamics, only statics. However, the theory works. Your camber isn't what is causing the wear on the inner edge, as has been pointed out in other threads.

I understand what your saying and I agree that our tires are not solid but they are not soft like party balloons either. These tires have very stiff sidewalls and minimal deformation. They're not Suburban tires.

Going by your rationale, how would you explain why does an over-inflated tire wears faster in the middle than on the edges . . . or why does an under-inflated tire wear faster on the edges than in the middle if the tire always deforms to match the ground? Wouldn't the answer be that different parts of the tread are experiencing different levels of friction/pressure with the road and hence wearing at different rates?

If negative camber is not causing wear on the inside of my tires . . . I would love to hear what is causing it? I must have missed the jests of the previous threads.

[anerbe]

shaving a tire is for racing. it's to get more of the rubber to contact the ground with an agressive camber setup.

not shaving your tires, they will eventually wear to an even footprint on the ground, which typically means more inner tire wear.

the tire footprint (area of contact on the ground) is effected by the inflation, alignment settings, contour/construction/tread pattern of the tire.

to summarize.

if you need the highest levels of grip right now, shave your tires. If you can wait and want more miles out of your tires, dont.