sandieganLA

I have Googled this and not found the right answer I am looking for -- perhaps I am not using the right language. A month or two ago I swapped the OEM Ultegra cranks on my Trek 5200 double with the Shimano Claris cranks (since it is a compact). Both use the Octalink BB, which I replaced within the last 5k miles, so I used the same BB. I had a shop put it on for me. However, the non-drive side crank arm will shift forward a little on the down stroke, or will shift back a little if I am doing a trackstand with my weight on it the opposite direction. I can see it happening if I hold myself in place on top of the bike, so it's not something else, it's the crank. I have torqued the bejesus out of it to attempt to tighten it, with all the weight my body has, and it still goes back and forth a bit. It also makes noise when this happens, which is annoying. Any thoughts on how to remedy?

Andrew R Stewart 

Take the arms off the Bb spindle and look at their splines for damage. If damaged then replacement will be in order most likely. If damage exists return to the LBS and talk with them. Not saying that they are responsible or not without more info, but they should know and might be willing to help. Andy.

HillRider

Did you directly substitute the Claris crank on the existing Ultegra Octalink bottom bracket? If so that's a problem. The Ultegra, 105, etc. Octalink cranks used a 109.5 mm (double) or 118.5 mm (triple ) V-1 Octalink bottom brackets. The Claris uses a 113 mm Octalink V-2 bottom bracket. Not only is the overall length different but the spline designs aren't the same. These are not interchangeable and you probably have to change your bottom bracket to make it work.

Andrew R Stewart 

I was wondering about V1 and V2 Octalink and the cranks listed. I hope the OP hasn't suffered arm damage. Andy.

sandieganLA

D'oh. That'll do it. Very helpful. Thank you!

Fortunately the Claris crankset was only 30 bucks on Nashbar, so if it is damaged, NBD

shelbyfv

If the bike shop installed the crank on an incorrect bb, I expect they will make it right for you. You will have to buy the correct bb, of course.

Andrew R Stewart 

This all depends of who said/requested/was told what and when it was or not said. Is a shop responsible for doing what a customer requests after informing the customer that the request isn't a standard practice but won't create a safety issue? Andy.

shelbyfv

My understanding is the shop installed his crank on a bb with a different spline configuration.

sandieganLA

I don't begrudge the shop. I would say it's largely my fault. I showed up with a random crank, and they asked if it was same BB, and I said yes, as if I knew so quite well, and probably seemed eager to make it work.

Since V2 BB is not made in 68 x 109.5. I will have to get another crank....? NBD as this one was only thirty bucks.

Is there a 9 speed crank I could buy that would work with Octalink V1? Or is my best bet to scrap the Octalink and just find a new crank + BB (what would be a cost effective route there?? I commute every day so the bike is not a garage queen). I haven't wanted to upgrade to a new bike / group, but it is cumbersome to keep trying to find 9 speed parts.

Thanks for all the responses.

CafeVelo

I bought an octalink ultegra crank to replace a ritchey one that I snapped on eBay for ~$30. They're far nicer than Claris cranks and will work with your system. Probably the cheapest option and should last forever.

Jamminatrix

You have a 68mm shell and the V2 crank comes in a 68mm option. The spindle width is determined by the crankset.

If you already bought the Claris crank you want because it's compact, you can try and buy the V2 Octalink BB and hope the crank isn't messed up too badly.

-V1 BB with V2 crank
-V2 BB with V1 crank
^One of these mismatched setups totally ruins the crank, but the other way is still salvagable when used with correct matching BB. Unfortunately, I cannot remember which is which.

Ultegra 9spd doesn't have a compact option since they're 130BCD.

Bill Kapaun

Eric S.

I put an old Ultegra 6500 crank/Octalink BB on a new build and had something similar happen as the OP. They came on a bike I bought new years ago so there was no mismatch.

Everything was tight and looked good, but when I pedaled away the first time, the non-drive arm slipped. I pulled it off, there was no damage, put it in a different position, and also moved the drive side to match. Everything's been fine after that. Don't know why it wouldn't go on right in the first position I put it in.

fietsbob

Octalink from Shimano , has not been produced in a long time.. Maybe BB spares ..

you may be shopping for a complete replacement .. Square Taper.

well biked

The road compact Octalink Claris crankset uses a 68 x 113 Octalink V2 bottom bracket, Shimano BB ES-25 68 x 113. They're readily available, QBP stocks them, for example, and they also stock the Octalink Claris cranksets.

sandieganLA

Swapped to the compact double V2 ES-25 BB (decided to get myself a Pedros crank puller ). Everything is all better now. Thanks for all the help.

Andrew R Stewart 

Great that you have a solution, and thanks for closing the loop by giving us the results. Andy.

rmfnla

I realize it all got sorted out, but the above still doesn't fly.

Any decent shop will be able to recognize incompatible parts and advise you of your options.

Do you think they would install a 20" wheel on your bike just because you asked them to..?

bradtx

+1