First of all, I did search and found the following:

Tire cupping could be attributed to: bad shocks, alignment out of spec, wear on the suspension system (?), high offset and wider tires, and incorrect tire pressure (too high?).

I just changed my tires last night to all season tires for winter driving, and I noticed that my Dunlops 9090 were cupping both in the inside and outside shoulder blocks. Shocks and struts are brand new (AGX with Maxspeed at 110k)...about 12k of use (now it's 122k)..all suspension components are new (I build the whole 4 corners without using any used components), tires are 235/45-17 with excellent tread in the center blocks, offset is 35mm, and tire pressure are 35 front ad 33 rear. AGX is set at (1) for fronts and (6) for rears.

Now, I want to know what factor in the alignment that causes this? Camber? Thrust? or Caster?

I am suspecting my caster angle are off since the cupping only happensin the outer blocks (hence it only happens when I am making a left/right turn).

Looking for any ideas that you guys could come out with to solve this problem.


Thanks!

Armand

 

Another thing....I have RSB and FSTB, but not RSTB installed. Will these cause uneven tire wear since they are forcing things to "stay planted"?

BTW, the tires were put in at 110k (same as new suspension), rotated at 119k....so all 4 tires have cupping and I wasn't able to determine whether the fronts are producing these, or the rears.....