# Speed Wobble on Tarmac



## nelgwoltrap (Sep 14, 2005)

I have a 2007 Roubaix Expert and 2007 Tarmac Expert and experienced a speed wobble for the first time on the Tarmac. I was going down a hill (hitting about 45 mph) and experienced a significant speed wobble on my Tarmac. I have descended this same downhill dozens of times on the Roubaix without a speed wobble. I normally ride my Tarmac in another state (that has no hills) where I work every other week but decided to take the Tarmac home and ride it in the hills. 

Has anybody that has both a Tarmac and Roubaix experienced this issue and have a suggestion to alleviate it? I love both bikes but am concerned about the speed wobble, that I experienced with the Tarmac, and now a little skittish about riding the Tarmac in the hills. Any feedback will be appreciated.


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## SwiftSolo (Jun 7, 2008)

nelgwoltrap said:


> I have a 2007 Roubaix Expert and 2007 Tarmac Expert and experienced a speed wobble for the first time on the Tarmac. I was going down a hill (hitting about 45 mph) and experienced a significant speed wobble on my Tarmac. I have descended this same downhill dozens of times on the Roubaix without a speed wobble. I normally ride my Tarmac in another state (that has no hills) where I work every other week but decided to take the Tarmac home and ride it in the hills.
> 
> Has anybody that has both a Tarmac and Roubaix experienced this issue and have a suggestion to alleviate it? I love both bikes but am concerned about the speed wobble, that I experienced with the Tarmac, and now a little skittish about riding the Tarmac in the hills. Any feedback will be appreciated.


Just curious---did this occur near the end of a long difficult ride?


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## j.knight (Dec 14, 2005)

I have found speed wobbles are usually caused by wheel problems and improper weight distribution on the bike. Try moving your weight further back or try a different front wheel.


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## g-Bike (Jan 25, 2006)

Also if your headset is at all loose at the higher speeds this will make the front end start to wobble. It happened to me descending climbs in Santa Rose once. After the first 2 45+ mph descents I stopped found the culprit, tightened it up and never have experiences it again.


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## SwiftSolo (Jun 7, 2008)

I've occasionally had this issue on my Tarmac. It only happens at the end of long difficult rides on high speed decents. Had it happen on both dura ace and Mavic wheels.

I've been suspicious that it may be me because the same decents on shorter rides do not produce the problem. I'm convinced that my tired nerves play a role, but I'm not sure.


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## nelgwoltrap (Sep 14, 2005)

Thanks for the replies. It actually happened at mile five in the ride. I've haven't done that climb in a while and my legs were fatigued so it may have been due to the tired legs. I will also check the headset.

During the descent my first thought was that my weight distribution was wrong. I experimented with the distribution back and nothing seemed to help.  If the weather holds out I'll do the ride again this weekend and let you'll know if it happens again. Hopefully I'll have an opportunity to ride both bikes.


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## nelgwoltrap (Sep 14, 2005)

I found the problem this weekend. I checked the headset and it feels just right however I noticed that the hubs were loose. It had to be a combination of weight distrubution and loose hubs. I didn't realize how loose the hubs were. Descended the first hill slowly and only got up to about 35 mph and let it loose on the next two descents going over 45 mph and the bike was steady as can be. Thanks for all the responses.


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