[G-Cracker]

Hey all...

Installed a brand new shimano Tiagra crankset on my commuter, along with an Ultegra BB (octalink) a while back. I didn't tighten the bolt enough and the left (non-drive side) worked loose, and now I am certain it wore the crankarm enough that there is considerable movement in the crankarm with each peddle stroke.

I can plainly see the crankarm shifting on the BB so I really think I will have to replace the left side. So I have a couple questions:

1- is there anyway to save this crankarm? I read somewhere that you can shim up the loose areas with alumimum from a soda can. Anyone ever done this?

2 - What do you think the chances are of the BB being ruined as well? Aren't the splines steel? If so, I'd hope they wouldn't have worn... just the aluminum crankarm. They only have about 300 miles on 'em.

I want to sell the bike and have an interested buyer whom I've told of the issue. It's basically a generic steel frame that I built up with 105/Tiagra parts. I was going to sell it for $250 and not sure how much I should knock off b/c of the crankarm issue.

Any thoughts/suggestions?

 

[sanjuro]

The crankarm is aluminum while the bb spindle is steel. Typically when the crankarm comes loose, the arm gets rounded off but the spindle is fine.

 

[recidivist]

The conventional wisdom is that once you've run an octalink crank loose, it will never stay tight again. My experience is that it's true...I ran a crank loose for a while and I was tightening that crank bolt every week from there on out.

I was able to "fix" it after a while though by loctite-ing the crank bolt and then really torquing it in good. Of course, you may never get it apart again (I did, eventually, using a heat gun)

 

[G-Cracker]

Yeah I'm pretty sure the crank arm is ruined. I"m going to head to my local bike salvage 'build your own bike' place and see if they've got a suitable replacement arm. Thanks for all your help, peeps.