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Really bad shimmy at slow spead….(3 posts)

Really bad shimmy at slow spead….TFerguson
Jun 9, 2003 6:08 PM
I was racing my Litespeed Classic at "stock road bike" night at the Velodrome last Friday night. After the finish of a 3 lap scratch race, I was slowing down and the bike developed a real bad shimmy. People in the stands later told me they saw it. I clamped my knees to the top tube and it quit. I was probably only doing about 15 – 20 mph at the time. The track is really rough, but no worse than a lot of roads I ride. I've heard of shimmy developing on fast descents, but not at low speeds. Is there something mechanical I should check? I immediately checked the headset and front hub. Anything else? Maybe I'm just holding on too tight. I love racing, but I am tight.

Thanks for any ideas,
TF
re: Really bad shimmy at slow spead….Fredrico
Jun 11, 2003 12:32 PM
That happened to me on my bike with steep headtube angle, as I slowed for a stoplight. Too much body weight over the front wheel caused it, I think. The wheels were true and round, tracked the same line, headset wasn't too tight or brinelled, frame and fork were in alignment.

I also got a really scary shimmy on a fast descent, for the same reason, too much body weight over the front wheel. Scooting back on the saddle and easing my grip on the bars made it go away instantly. This probably wouldn't work at a stoplight, but shifting the butt back on the saddle when coming to a stop, especially on a banked track, would probably prevent it.
Something to chew onpeter1
Jun 16, 2003 1:57 PM
Tires? I have found that slightly out of round tires can cause shimmy, esp. when new. Also, maybe going left so many times has changed the wear pattern? Just a thought, if everything else checks out alright.