# Roubaix wobble at speed



## shibaman (May 2, 2008)

I have an 06 Roubaix Expert with a triple I use for hill rides and centuries. Great bike to do the miles on in some comfort. I have found that going down the hills at 42 + mph some times I get a shimmy or wobble in the front end. This has happened to me a few times. Is this a common problem with this frame? It has done it with 2 different wheel sets. My other rode bike does not do this on the same roads.


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## darkest_fugue (Mar 14, 2009)

im not an expert on this but it could be your fork


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## PJ352 (Dec 5, 2007)

IME this is a tough problem to diagnose because it could be a combination of things, but a loose/ worn headset is the first thing to check.


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## P.D.E. (Oct 15, 2006)

shibaman said:


> I have an 06 Roubaix Expert with a triple I use for hill rides and centuries. Great bike to do the miles on in some comfort. I have found that going down the hills at 42 + mph some times I get a shimmy or wobble in the front end. This has happened to me a few times. Is this a common problem with this frame? It has done it with 2 different wheel sets. My other rode bike does not do this on the same roads.


I rode a stock 06 Roubaix Expert double for a couple years and on an almost daily basis I would hit 42-45 on my standard training route. A handful of times got it up to 50. Not once did I have a speed wobble.


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## badge118 (Dec 26, 2002)

shibaman said:


> I have an 06 Roubaix Expert with a triple I use for hill rides and centuries. Great bike to do the miles on in some comfort. I have found that going down the hills at 42 + mph some times I get a shimmy or wobble in the front end. This has happened to me a few times. Is this a common problem with this frame? It has done it with 2 different wheel sets. My other rode bike does not do this on the same roads.


One suggestion and you may already do this. Have you tired pressing your knees to the top tube? Sometimes things like this can be because of fork, head set, wheel issues, it could also simply be a dynamic of the frame. Sometimes a sympathetic vibration can start and its as simple as pressing your knees to the top tube to stop it.

I ride a Roubaix but its the Pro SL so I don't think my specialized experience is relevant but the knee thing helped address the same issue with other frames in the past.


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## tom_h (May 6, 2008)

Possibilities:

-- loose or worn headset.
-- loose or worn wheel bearings. (although, experiencing this on two separate wheelsets makes it unlikely)
-- out of round or "twisted" tires ... spin both wheels fast as you can on a workstand and observe.
-- manufacturing defect in fork, making it asymmetrical. Is this a "new" problem or has it always been this way? Read: http://www.calfeedesign.com/forksymmetry.htm


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## shibaman (May 2, 2008)

I had the stock Shimano wheels on the bike first. I know that for sure that the Heliums on the bike now have been involved in this problem. Perhaps it could be the wheel set. It happens on very fast left corners. Not the straights.
I put my Rol SL wheels on there tonight and have found the bike to be much smoother on the rough roads than the Heliums. Stronger wheels! Tomorrow I will go down the same hill that causes the shimmy and see what happens.


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## Dr_John (Oct 11, 2005)

PJ and tom_h are right as usual, but as an owner of an '06 Roubaix "Expert," I'll comment. I put the Expert in quotation marks since after seeing this thread, an inventory of that bike revealed the only things original on that bike are the frame and rear derailleur.

In my experience the original wheelset and front fork were down-right scary flex-wise. Bombing down a hill and into a corner the wheel/fork would flex enough that the rim would hit the brakes. A wheel replacement helped there, but the fork was still flexy enough to not inspire confidence. I recently replaced the fork with a Ritchey WCS fork... a night and day difference. And while not the intent of the fork replacement, my little century bike is now unbelievably under 16 lbs. There is a little more road buzz, but I really enjoy the bike a lot now.

I'm not suggesting that the wobble is due to fork flex, but it may be amplifying the result of the true cause others have mentioned.


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## towerscum (Mar 3, 2006)

*fork*

fork flex and/or geometry.
make sure your headset is properly installed too,


towerscum


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## shibaman (May 2, 2008)

tom_h said:


> Possibilities:
> 
> -- loose or worn headset.
> -- loose or worn wheel bearings. (although, experiencing this on two separate wheelsets makes it unlikely)
> ...


Interesting reading. Good info on the forks. Today I am going down the same hill that caused the shimmy. It is a short, but very steep hill with corners. I hit 56mph on my Dale System Six before I hit the brakes to make the corner. 
I am hoping that it is the Heliums flexing through the corner. That wo uld be the easiest fix. If it does it with the Rol SL wheels, I am back to the fork/ frame.


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## Tarbaby09 (Jun 18, 2009)

Is this fork flex and associated issues still prevalent with the 2009 Roubaix expert? I have been thinking about getting one but maybe there are issues that I need to investigate or possibly look at other brands as an alternative.

Anyone got the 2009 model?


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## shibaman (May 2, 2008)

Dr_John said:


> PJ and tom_h are right as usual, but as an owner of an '06 Roubaix "Expert," I'll comment. I put the Expert in quotation marks since after seeing this thread, an inventory of that bike revealed the only things original on that bike are the frame and rear derailleur.
> 
> In my experience the original wheelset and front fork were down-right scary flex-wise. Bombing down a hill and into a corner the wheel/fork would flex enough that the rim would hit the brakes. A wheel replacement helped there, but the fork was still flexy enough to not inspire confidence. I recently replaced the fork with a Ritchey WCS fork... a night and day difference. And while not the intent of the fork replacement, my little century bike is now unbelievably under 16 lbs. There is a little more road buzz, but I really enjoy the bike a lot now.
> 
> I'm not suggesting that the wobble is due to fork flex, but it may be amplifying the result of the true cause others have mentioned.



I think that you hit the nail on the head! I put my Rol SL wheels on the Roubaix and went down Beatty dr. It is a short climb (.75mi.), but very steep with corners. It was much better than before because of the stronger wheels, but the front of the bike was still trying to move around. I am inclined to think that it was the fork, and the over all compliance of the frame. I am amazed how much this frame flexes under me when I am seated hammering down the road. With the Rol wheels it is a very smooth, comfortable bike. 
I guess it comes down to if I want to use it as is, or spend the money to put another fork on it. I could also strip the frame and put the triple parts on an extra System Six frame that is waiting in the garage. I just have to figure out which way to go.


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## brujenn (Nov 26, 2007)

Maybe the different geometry has you pressing on the bars to hard when you go aero. Have you tried moving your weight back, and easing your grip?


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## shibaman (May 2, 2008)

brujenn said:


> Maybe the different geometry has you pressing on the bars to hard when you go aero. Have you tried moving your weight back, and easing your grip?


the Roubaix flexes on the hoods, or the drops when I hammer. My Specialized langster, Trek Y-Foil, and Cannondale System Six do NOT flex when I put the hammer down. I Think that the Roubaix is a very comfortable frame, at the expense of stiffness and climbing/sprint ability.
As a side note the Langster, with the road drop bars is a hell of a bike! It is my favorite as an after work bust your butt bike. With a 42x16 gear set, and a very strong alum. frame it is actually a very fast bike This simple SS has made me stronger on my geared road bikes.


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## pgk (Jun 30, 2008)

If memory serves I believe Specialized beefed up the fork on the Roubaix not sure what year though..


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## MDGColorado (Nov 9, 2004)

I have an 04 Roubaix Comp that also goes into a little shimmy over 40 mph. Fortunately I don't hit 40 very often. In any case, just lay a knee against your top tube to dampen it.


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## shibaman (May 2, 2008)

I did the Santa Cruz Challenge 100 mi. ride on Sat. On the down hills the front of the bike wobbled quite a bit. Rough roads and a lot of speed! One down hill was 9 mi. 
Took it to my LBS who is a Specialized Store and they found that the head set was loose.
They felt that it was the cause of the problem, not the Mavic Helium rims. They also lubed the carbon seat post so it doesn't creak any more.
This Sun i am doing the Shasta Century. We will see how the bike feels going down the hills.
It was kind of funny. At the first water stop there were 2 other Roubaix just like mine, a 06 expert. Other than the head tube problem the bike was the right choice for the rough roads. It really soaked up the the bumpy surface.


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## shibaman (May 2, 2008)

My LBS tightened up the head set. It has removed the shimmy. Over all I am now pleased with the bike for doing Centuries. It is a very comfortable bike.


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## customsteel (Feb 15, 2003)

shibaman said:


> the Roubaix flexes on the hoods, or the drops when I hammer. My Specialized langster, Trek Y-Foil, and Cannondale System Six do NOT flex when I put the hammer down. I Think that the Roubaix is a very comfortable frame, at the expense of stiffness and climbing/sprint ability.



What year is your Roubaix? Reports and rider reviews show that the 2009's are much stiffer!


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## superflychief (Mar 25, 2008)

I've got on 05 roubaix elite. I regularly get it over 40m/h and sometimes over 50 and i've never had a shimmy. Check your components for looseness and wear.


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## shibaman (May 2, 2008)

My Roubaix is a 06 Expert with Ultegra. Since i had the head set tightened up the front does not shimmy or wobble on high speed hills. It is a very comfortable frame but, but you do loose some performance while climbing or hammering. I bought this 06 from a friend who bought a 09 Expert. Stiffer, but still comfortable.


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## zacktown (Aug 22, 2009)

2010 roubaix expert, 3 weeks old, same problem. My wobbles start at 35 mph. Sometimes clamping my knees against the top tube will help until I slow down a bit. Getting off the seat a bit helps too. However, I ride too close to these speeds to frequently for it to be acceptable. I know it isn't me since my mountain bike on the same hills at the same speeds has no issues whatsoever.

I had a LBS tell me that it might be the carbon fork not being true. I hear that this is a common issue with carbon forks. So now it appears that I will have to go through a long process of fork testing. I am hoping that specialized will take care of this under warranty.

I also know that calfee will check the fork, but I am trying to do this without coming out of pocket any more than I have to. http://www.calfeedesign.com/forksymmetry.htm


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