Rubrignitz

Lol, funny you should mention this. I ALSO have steeda ultralite 18x9.5's along with sumitomo HTRIII in 275/40 up front and minor shake. And I DONT HAVE WHEEL CLIPS.

I ordered my wheel/tire package mounted and balanced from americanmuscle.com. They seem to have weighted the wheels but I haven't removed and had them rebalanced yet (too busy working on the rest of my suspension at night and working my *** off during the 10 hours I work per day). And getting to a tire shop in austin, tx on the weekend is f-in brutal.. all day affair. None of these hippies and yuppies know how to work on thier own cars here so you can't find a shop w/o a 2 hour wait.

I will have them rebalanced eventually but haven't yet... keep us updated on this or I will when I get the time to have them rebalanced.

Rubrignitz

It's got to be a "balance" issue but I've also heard stories of the steeda ultralites being "warped". Also I noticed the sumitomo's have red and blue dots on them, signaling valve stem orientation. The valve stems are nowhere near either dot. If these rims are warped I'll be getting a refund.

Poco

Are the rims you got hub centric?,if not check to see if they used centering rings.Some new wheels are not hub centric and require centering rings.Another possibility is if they did use centering rings one may have been crushed on the install causing the wheel to shimmy.
I'm just trying help eliminate all possibilities. Many s-197 owners have posted a number of reason for shimmy problems.

rdsx18

+2, it is most definitely that, I had forgotten to take them off the first time around and the steering wheel shook so much at anything above 45mph. Took them off and it is great now.

Smooth_J

Its the clips - it caused my issue and most likely it yours as well

wingman75

Is there a clip on all 4 wheels? I installed my own wheels/tires and did not remove any clips but it tracks straight and true and NO shimmy at all..

ZERO4572003

It was the clips for me after i took them off it was good no shakeing.

Nuke

It varies from car to car. I had 1 clip on 1 wheel, 2 clips on another and no clips on the other 2.

I had forgotten about the centering rings. Clips would still be my #1 guess followed closely by centering rings. Good call, Poco.

PennState

yeah i took the clips off, and it helped big time..

Rubrignitz

Yeah, thanks for mentioning the centering rings Poco. I remember seeing them on my shelby razors but not these new steeda ultralites. I would think american muscle would have included them... maybe not. I'll have to check that out.