# Wobble 09 defy Advanced 1



## dtrancex (Jun 17, 2009)

Got a speed wobble last week going downhill @ 25MPH. Went to LBS, took fork off cleaned and reset. Everything was fine until today, Small downhill @15MPH samething. Back to LBS, cannot find anything wrong. Putting bike up on rack and noticed some scuff -tearing on side wall. Went back in -they put a new tire on---much better @ 35MPH--Don't have the guts right now to go faster----we've ben to 45 MPH and felt great
They checked the wheels - bearings -spokes
Does this make sense to anyone--only happens downhill


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## Chris Oz (Oct 8, 2005)

Speed wobbles are usually caused by the rider, although early Giants were more prone to them than some other early compact frames. When descending you need relax, don't tense up. It is less likely to be your bike and more likely to be you.


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## PJ352 (Dec 5, 2007)

Chris Oz said:


> Speed wobbles are usually caused by the rider, although early Giants were more prone to them than some other early compact frames. When descending you need relax, don't tense up. *It is less likely to be your bike and more likely to be you*.


Actually, that's backwards. It's more likely to be the bike/ components, but the rider can be a contributing factor with poor weight distribution (fit) or by shifting their weight front/ rear.

IME the most common cause is a loose/ problem headset. Next would be loose wheel hub bearings. From there, the cause maybe attributed to a loose skewer, misaligned frame/ fork, spokes catching a crosswind or a combination of any number of factors.

The specific cause found by the OP may be somewhat unique, but it does reflect the fact that the bike/ components are the more common cause.


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## Chris Oz (Oct 8, 2005)

PJ352 said:


> Actually, that's backwards. It's more likely to be the bike/ components, but the rider can be a contributing factor with poor weight distribution (fit) or by shifting their weight front/ rear.
> 
> IME the most common cause is a loose/ problem headset. Next would be loose wheel hub bearings. From there, the cause maybe attributed to a loose skewer, misaligned frame/ fork, spokes catching a crosswind or a combination of any number of factors.
> 
> The specific cause found by the OP may be somewhat unique, but it does reflect the fact that the bike/ components are the more common cause.


There are a number of factors that can contribute to the so called death wobbles, but if you follow the common wisdom it is poor descending skills that allow death wobbles to build and get out of control. The most common advise is to rest your knee on the top tube if wobbling starts to occur and to relax the upper body. Hey but your mileage may vary.


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