BB & Chainset Replacement

Donie75 Posts: 92
edited July 2011 in Workshop
I have a 2010 Specialized Secteur Elite with mostly Shimano 105 5600. It has around 3500km on it and I have started doing more maintenance on it myself.
The BB makes a bit of noise from time to time and I was thinking of buying an Ultegra or 105 BB on Wiggle and replace it myself. It seems to be a high load point and as I am fairly strong and very heavy I think it is a part that might be worth replacing. Will a 105 BB fit my bike?

Also, the chainset on my secteur is a Shimano FCR-553. This seems to be a non standard/non groupset part. I may replace this for a 105 5603 chainset or something similar. Is this compatible with my Secteur?