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Wrong BB with new chainset?

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!!

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)?
Have you adjusted the limit scews on the front mech?

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