Hi, I was wondering if someone could help me out please, the LBS is closed for Easter!

I had my bottom bracket replaced at the LBS last week and requested a 123mm BB as the Shimano techdocs (http://techdocs.shimano.com/media/te...9830621467.pdf) stated this would be compatible with my crankset and Front Derailleur (FC M311 and FD M311).

However, now the front derailleur will not reach out as far as the large chainring when pushed manually. My front chainline now seems to be about 52mm.

I therefore have 2 questions;

1) Does this mean the BB length is too big?

2) if so, why did the techdocs specify a 123mm?

I can't blame the LBS and it doesn't seem that I'm at fault here either but replacing the BB again seems annoyingly likely.

Thanks very much.