I just traded in an '05 coupe for the '05 roadster. I drive exactly the same roads and highways so I know when the roadster switches to square wheels at about 30, it is not my imagination. I took it to the dealer and had all 4 wheels balanced. It made a slight improvement, but not enough. In the coupe, the steering wheel had no vibrations at any speed, but the roadster's starts to vibrate at 30 though it doesn't get any worse up to 80+. Any ideas?

 

An out of round tire or two? Have the dealer put on your old tires, take it out for a check ride and see what happens. Good luck.

 

Yes, it's possible that the rolling surface of the tire isn't perfectly round even though it's balanced. +1 for seeing if they'll let you test it out on your old tires/wheels, and if the problem remains you know it's suspension/alignment related. If it goes away, try finding a place that does Roadforce balancing on the tires as well as traditional balancing (with the Hunter GSP9700). They test the rolling surface under load while still on the machine to get rid of any possible vibrations. With these kind of tires, it can make a big difference. I had it done Friday when I put my new Michelins on, extra $10 a wheel and nice and smooth (up to 90 so far, further testing to come ). If you want to know more, go here: http://www.gsp9700.com/

 

I have taken corners that would have scared me in my Mustang GT that my Roadster flew through with no vibration or trouble. I'm thinking there is a mechanical problem - I doubt it's the Roadster body style causing the problem.

 

I agree with Gibson...my Roadster Limited takes curves with no vibration and is as smooth as glass at 90+.

 

Out Of Round Tires Or Bent Wheel!!!

 

Thanks for the suggestions. Going to have the Continental tire dealer check it out first.