Wrong BB with new chainset?

[ianlew2303]

Hello,

I have a 2009 Trek 7.3fx. I recently bought a new BB, chainset and front mech for it. All of the parts (Shimano Alivio and UN-26 BB) are supposed to be compatible, but now that I have installed them all, the front mech doesn't work.

No matter how hard I pull it without the cable on, it only ever comes level with the biggest chain ring, and won't encompass it - so I can't change into top.

Is it possible that even though I got exactly the same size BB (68x122), that the new FM needs a shorter BB?

Many thanks!!

[nfmisso]

Yes.

It may be the FD or the crankset. What does the chainline look like (alignment of the cogs at there rear versus the chain rings at the front)?

[torquecyclerepairs]

Have you adjusted the limit scews on the front mech?