Author Topic: Speed wobble  (Read 5238 times)

xrayspecs

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Speed wobble
« on: December 14, 2013, 02:28:29 PM »
Not sure what happened this morning but my bike started violently wobbling side to side at about 20-25 mph.
Thought I had front puncture so stopped. Bike all OK. Wind over my right shoulder / side.
Anyone experienced this, I've had it before at 45 mph + but not at a slower speed???

Rob Jones

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Re: Speed wobble
« Reply #1 on: December 14, 2013, 03:09:35 PM »
Never. Not even down the bank at circa 50mph...reckon speed wobble is an old wife's tale...

Chris Tasker

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Re: Speed wobble
« Reply #2 on: December 14, 2013, 06:35:20 PM »
I've had this coming down the dual carriageway towards Cowbridge from Bridgend. I eventually found mine to be the lower headset bearing had developed a flat spot from a failed water seal.

Bring it round on Monday evening and I'll have a look at it for you if you'd like?

Could be something else of course?...

Chris

ron b

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Re: Speed wobble
« Reply #3 on: December 15, 2013, 11:54:11 AM »
Wobble at such a low speed, front forks, head set. Worn headset would alter the camber and the forks would move, get it fixed or it will get worse very quick. Replace the head set, check for play in the head  by trying to move the forks with your hand, or put the front brake on and rock the bike and check for movement through the bars.

xrayspecs

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Re: Speed wobble
« Reply #4 on: December 15, 2013, 04:13:36 PM »
The bike is only a few months old.
I've checked all of that at the time, and it was fine on todays club run. The conclusion has to be that it was wind related, the mudguards do catch it quite well.
Andy H and myself reckon the wind passing through the bike from the side reached the frequency necessary to make it resonate from side to side.

traine

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Re: Speed wobble
« Reply #5 on: December 16, 2013, 01:19:28 PM »
Very un-nerving. I have known it happen a few times (not to me) with very nasty results. Get it fixed as soon as you have a suspect part.

I have heard it may have to do with the rake of the forks but it could be the wheels. Certainly small front wheel bikes seem to be more prone to it. Try Google ?

Tim


Chris C

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Re: Speed wobble
« Reply #6 on: December 23, 2013, 07:41:19 PM »
I had that happen to me once and I understood it to be diesel on the road, maybe the same in your case.