Rear wheel question.

[dkl]

Originally Posted by JCL

What usually causes rapid wear on the inner edge of the tire is toe-in, the tires being pigeon-toed and not pointing straight ahead. This is also adjustable. If the tire is pointing inwards a few degrees, but is forced to roll straight (in line with the vehicle), then both the inner and outer edges are continually slipping (skidding), only the centreline of the tire is rolling without slipping. Both inner and outer could theoretically wear, but the inner tends to wear more, due to the negative camber. Fix the toe-in, to the minimum of the spec that BMW publishes, and you will often get much better tire life.

With wider tires, the toe-in problem is amplified. Also, sport tires often have softer compounds that wear faster anyway.

Only trouble is that you can't see the toe-in (the vehicle is in the way) so you will still get discussion about the negative camber, which you can see easily.

I believed that toe-out will cause more inner wear than toe-in. Toe-in will cause the outer edges to wear more. The factory setting does called for a smidge toe-in.

[ard]

Originally Posted by dkl

I believed that toe-out will cause more inner wear than toe-in. Toe-in will cause the outer edges to wear more. The factory setting does called for a smidge toe-in.

With flat camber, yes.

But to assert that inner edge wear CANNOT be due to toe in is wrong.

[JCL]

Originally Posted by dkl

I believed that toe-out will cause more inner wear than toe-in. Toe-in will cause the outer edges to wear more. The factory setting does called for a smidge toe-in.

Since the spec calls for toe-in, I think it is more likely that there will be too much toe-in than that there will be significant toe-out. Either can wear the inner edge or outer edge, but with negative camber I would expect the inner edge to wear more in either case.

[HAMAR]

This is the result from a negative camber on the rear tires:



These tires have 21.000 miles (34.000 km.) on them and I had no idea that they were that bad

[ard]

Originally Posted by HAMAR

This is the result from a negative camber on the rear tires:



These tires have 21.000 miles (34.000 km.) on them and I had no idea that they were that bad

Wrong...IMO that is the result of improper toe.