I was wondering if anybody has a suggestion for my problem.

I am a grad student with a 2004 Mini Cooper S (109,000 miles)and I have been having a problem with the inner part of the rear tires showing excessive wear. From what I have read in the Bentley manual, the tire is cupping.

I had replaced the rear shock absorbers about 8 months ago, I have also replaced the 4 rear control arms after i had a double failure on the interstate at 70 mph, with after market control arms.

I was then hit about a week later by a women drinking a coffee. The car was parked on the street, and she was taking a sip....and turned right into my car. As a result, $4800 worth of damage was done to the left rear.

Since all this, i have gone thru 2 sets for tire (16,000 miles, all highway) from tirerack because the inner part of the tire is wearing out. Any thoughts why?

I have had the alignment checked by two different shops and they claim it is accurate.

What should i do next, tires are expensive!!!

Thanks,

Mark Bates

 

How often are you rotating the tires?

 

The last two times about 5,000... or when i do an oil change. but the cupping is already showing by then.

 

What were your alignment specs on the toe in the rear? Excessive toe will cause severe inner tire wear.

 

Total toe is .35 degrees, with the left .22 degrees and the right .14 degrees.

This is from the alignment sheet given from the shop, done 7 months ago.

Would excessive toe cause the inside to wear smooth?

My tire has an even high then low spot on it, all the way around.

 

If the inside tread is wearing excessively it is caused either by too much toe out or too much negative camber.The toe specs given don't seem to be too far out if those are the actual readings.Does the spec sheet give you a camber reading? If is showing -X degrees that could be some of your problem.The higher the number the more neg. camber it has.The tire cupping can be caused by a few different things.Shocks with too much compression damping will cause it to bounce,loading the tread in spots depending on the frequency of the bounce. Binding suspension arms can do the same as can tire balance.Lastly the design of the tread can contribute to the cupped wear.If it has chunky,free standing tread blocks they can wear in a cupped pattern if the suspension is stiff[like a Mini] and it is driven at high speeds with highish tire pressures.The sidewall stiffness and the suspension stiffness will make the tire bounce off the ground at a frequency that can be almost be seen if the tire is worn enough.Have the alignment checked and tell the shop what the problem is so they can help pinpoint the cause.

 

Is the car lowered?? if you just put lowering springs without changing anything else, this can happen.

 

The car has the original springs. I have Yokohama S Drive tires; What pressure do most people run in the rear tires? I will check what I am currently running when I get home.

Thanks all for the input so far :-)

 

Our MINIs have negative camber dialed into its stock alignment. This in itself would cause the inside tread to wear a bit faster, but allows for better handling.

A bit over a year ago I did a wheel alignment with snowtires on. The tread pattern is not as wide. When I switched back to summer tires (wider tread patch), some toe in was quite noticeable. It greatly improved my car's cornering abilities . But tire noise was noticeably louder, the suspension felt heavier at low speeds and the inside tread had a strange wear pattern. Last week I had another wheel alignment done right after I switched back to my summer tires. The suspension feels noticeable lighter and straightline drive is much smoother and quieter. However, I'm feeling a bit of understeer so outright fast cornering prowess has been reduced. Probably not a big deal for normal street driving. Even though the alignment person said he changed it very little.

Attached is a picture. Note the inside blocks. The wear pattern where every send block looks darker (less contact with the ground). Tire guy says something wrong with the suspension, MINI mechanic says something wrong with the tires. From the way it is consistantly wearing, I can only conclude it's just a bit too much toe in for these tires.

 

balance? control arm bushings worn?

 

Did you ever resolve your tire cupping issue? I had the exact same problem which was only resolved after taking my car to the official MINI service center in Atlanta. They claim their alignment wrack is specialized. Now I don't know if that's true, but after burning through 3 sets of tires ($!!!!) this resolved my issue.

At present, my new tires are doing 3/4 okay. My right rear is wearing ONLY on the inner half side. Very strange indeed. I just ordered a replacement tire and I'll take the car to a local BMW/MINI specialist to get it mounted and aligned. I would take it back to Atlanta but I live in Virginia now.

 

The solution, I found was new rears struts. I got a bad set of Sachs. After replacing them with new Sachs, they only last 25k. I replaced that set with bilstein HD. No problems after that. I do get frequent alignments.