ImprezaDrvr

I'd lay more blame on the bean counters than the engineers, but that's just a natural response.

henders

I think that I actually started the last shimmy thread after similar experiances. Here is some updates. I was having shimmy problems at about 40 mhp, since then I have changes my tires (after a suggestion) from racing 23c to 25's and the shimmy is gone. The same hill I now ride at 52 mph with no worries. This is the only ajustment that I have made to my bike or my riding style.

Dave Moulton

The gyroscopic action of the spinning wheel also helps keep a bike going straight; sometimes switching to a slightly heavier tire is all that is needed to stop a bike from shimmying. The design flaw is still there, but you have added a factor to correct it.

berkokid

I've read multiple threads on the board discussing the causes of 'shimmies' and the different approaches to solving. My conclusion from reading everyone's thoughts is that it is by no means an exact science and that each bike / rider / road / wind combo. presents a unique combination of factors that may contribute to the problem.

My situation: I'm a relatively new rider who encountered the problem on my very first ride. I ride a Ciocc 7005 frame with Campy Scirocco wheels and 700x23 tires. I have a natural tremor in my hands which I think is a huge cause of my problem. On steep downhills, when my weight is forward and more on my hands I *always* have a significant shimmy between 25 and 30 MPH depending on the road condition. I'm thinking of experimenting with three things:
1. wider tires (25's)?
2. getting a shorter stem (I currently have a 100, perhaps a 90 pushing my weight back more?)
3. would a nice, carbon stem like the Easton EC-70 help in vibration dampening at the handlebars? (expensive piece to experiment with).

Any thoughts or similar 'tremor' experiences?

TIA

cycletourist

That is good to know.

I think I read somewhere that using lower bottom brackets, longer chainstays and thicker walls on the head tube will supress shimmy. I don't remember who wrote it or why the author had come to that conclusion.