Mav

I just put my new 20" techno wheels on my CS. The techno's came with Pirelli P Zero. I drove my CS yesterday and my CS had no sign of shimmy or vibration on the steering wheel so far. My next door neighbor has the same techno wheels with Michelin Diamaris. He gets some vibration on his CS. My previous 20" sport design came with Continental 4x4 SportContact. My steering wheel was shimmy from the very first day. This let me think the shimmy problem maybe tire related for the most.

Moogle

the 'shimmy' is usually due to either improper wheel balancing, or not balancing at all.

vn1

I brought my CS to Grandprix Performance in Costa Mesa for balancing all 4 wheels when it had 15K miles on it and the steering wheel shimmy was gone. But my happiness did not last long. The truck's steering is now shimmy again and it has 19K miles on it. So I think I am going to balance all 4 wheels again.

Mulsanne-a-be

How bad is this shimmy for everyone? I have a new Turbo with 20" technos and continental tires and 'occasionally' I feel some "minor" vibrations/shimmy at various speeds (60 to 80mph) . . . I mean it seems minor, like it could be from road feel, but then again I don't feel it on my GT3 on the same stretch of highway. Just wondering how much I should complain. The dealer already rebalanced all four wheels with some small reduction in vibration feel.

ajauch

There have been various threads on this topic. I've recently had an interesting experience around the shimmy. I had mild vibration from 65-75. One dealer told me that it was a balancing issue and gave me a four wheel balance. This didn't do a thing. The second dealer told me the fronts were defective and gave me two new tires (Conti Sport 4x4's, 255/55 R18). This solved the problem temporarily. Then it came back. I was thinking "oh, no here we go again!"

The dealer took it back and re-did the road-force balancing. They said that the tires had "rotated on the rims" and gone out of balance. I pretty much assumed this was crap. However, I'm about two weeks into the current balancing and no vibration.

I've never had this kind of balancing problem before. I've seen tires wear unevenly and go out of balance after 8-9K miles. This seems to be especially true for larger tires (like on my truck). However, I've never had to take a set of tires back three times.

Alex