As above with HillRider, fogot about the V1/V2 spec.

Can you take your BB out? if so, it will have the exact spec you need printed on it, if your bike had a FULL 105 groupset, it would have had a 105 (5500) BB as seen here http://techdocs.shimano.com/media/te...9830612167.pdf pull yours, and replace with a matching BB.

If you can't remove, take it to a bike shop, and get them to replace, they can worry about spec / sizing