The Monk

Anyone have info on the stiffness of a Roubaix frame?

I've had my Specialized Roubaix for a few years now and recently decided to switch from a triple to a compact crank. I had a Shimano FC-R600 (the 105ish-level compact) installed as well as an Ultegra front derailleur. When I ttok it out for a spin I was unable to drop into my highest gear due to chain rub on the front derailluer. I took it back to the shop and the tech played around with it on the stand and it was working fine. But when he took it out for a ride it rubbed. He sighted frame flew as the culprit. He was able to tweak the position of the FD to slear the chain under most circumstances but it will still rub if there's any significant torque.

I was surprised to hear that the frame wasn't very stiff. From what I had read before purchasing my roubaix was that it was fairly stiff.

NealH

The Roubaix's are pretty stiff - the new models anyway. Though, they are as stiff as the Tarmac. I suspect yours is suffering some age related fatigue since it is several years old. The carbon formulation/layoup could have changed over the years also. They're always improving bikes.

You probably should check that bottom bracket area very close for a hairline crack also.

The Monk

The BB is brand new.

Fatigue may very well be the culprit. I'm a bigger guy and used to ride on the stock, low-spoke wheels before I upgraded to some 32-spoke deep Vs. I imagine I put the frame through some tough times.

Hocam

FD could be angled in slightly.

The Monk

correct. that's how we adjusted it to avoid the major rubbibg.

waterrockets 

Is the der low enough? I don't see how you go through a change of der, crank, and complete readjustment, to arrive at frame flex as the source of the problem. If it was fine before the change, it's fine now.

I say, pull the der cable off, unclamp it completely, clean the frame and der clamp, back out the stop screws 1-turn, and start from scratch with Sheldon's instructions.

v1k1ng1001

lose some weight or become weaker, then the frame won't flex as much

jbpence

i weigh in at 210, my roubaix elite triple isn't the stiffest bike in the garage, it has a LOT of 'verticle compliance', which is why I bought it. I lived in northern NM, the roads there can get pretty rough. The roads here in SE michigan get pretty rough too. In NM i used it for high speed descents (after putting on some stronger hand built wheels to replace the stock super flexy Amex 295's), and its stiff enough. yours could be worn, or even cracked if the flex is extreme.

waterrockets 

My point is that it wouldn't have cracked or fatigued right when the new cranks and der were attached.

Indolent58

Agreed.

The Monk

I think the key is the switch between a triple and double FD. The double has a narrower cage and less tolerance.
I don't see how the height (which appears to be correct) would effect the chain rub issue.

Also, consider that on the stand there is no rub. The rub only occurs with a rider in the saddle. Ordinarily I'd chalk it up to my size but the tech that tuned it was rail thin and had the same result.

waterrockets 

If the der is too high, it might be easier for the chain to reach it depending on the der angles near the back. I guess it would more likely be too low than not low enough. I think it's an adjustment that may be forgotten when going between different size chainrings.

I'd still start over with the derailleur adjustment.

All bbs flex some, and derailleurs generally can be adjusted to compensate.

The Monk

Thanks all.
I just went on another ride and found that the angle truly was the culprit. Any rub was minimal. I am curious about stiffness though. Maybe I'll go demo some steel to see what I'm missing out on.

af2nr

What year and model is your Roubaix? The higher end Roubaixs, Expert and up are pretty stiff overall, according to Specialized's Fact book even more stiff than the Tarmac in some cases. At least prior to the new SL2...

garysol1 

Correct...The Roubaix had the STIFFEST bb area of any bike in Specialized's line

biffstephens

I had a buddy the BB was the issue...it was flexing so much it would shift front gears when he got out of the saddle.....

Lost the TI BB and problem went away....I am sure the LBS would let you try a different BB to see if there is a differance....

The Monk

It's a 2005 Triple Elite. Not the top of the line.

As I said before, I had a real ptoblem with rigidity with the stock Alex rims and swapped them out with a high spoke stiff wheelset. I wonder though if the 1,000 miles I logged on those weak rims fatigued the frame in some manner.

garysol1 

Not a chance. Sounds more like an installation or adjustment issue to me.