I'm planning on replacing my Sora/Tiagra-based 3x8 speed drivetrain with 105 3x10 components this winter. Yeah, I know it would be more cost-effective to buy a new bike, but I'm doing it mostly for the fun and learning experience.
Anyway, the one component that I have never worked on so far is the BB/crankset. My current bike (Specialized Sequoia) has a Sugino BB/crank that is listed as having a "68mm axle". Is this a standard size and can I expect that the BB for the 105 crank will install with no problems in my frame?
Also, my current crank has 172.5mm arms. Is there any reason not to get the same length with the 105 crank? I'm strictly a recreational rider and have no particular issues with the current crank setup.