Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take Part in the May's Giveaway: Win the LIVALL PikaBoost 2 E-bike Conversion Kit


Wrong BB with new chainset?
#1
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!!
  Reply
#2
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)?
Nigel
  Reply
#3
Have you adjusted the limit scews on the front mech?
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Massive Chainring redux
Today 05:58 PM
POLL: Are non-recumbent riders looking a...
Today 05:26 PM
Third best reason to ride a bent or trik...
Today 04:51 PM
What was your first bicycle?
Today 04:48 PM
The great thing about trikes
Today 04:33 PM
First long distance ride..
Today 11:26 AM
Is anyone riding with music?
Yesterday 09:49 PM
Great Giro
Yesterday 08:32 PM
Quiet is good
Yesterday 09:38 AM
What is your favorite MTB trail/route in...
05-28-2025 06:55 AM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Painkiller
16 posts
no avatar 2. Criminal
16 posts
no avatar 3. Flowrider
16 posts
no avatar 4. GirishH
14 posts
no avatar 5. SPINMAN
13 posts