I ordered a Surly Cross Check frame (hasn't arrived yet) and the BB specification from the website says the BB is 68x113mm, the BB I have is a 68x107mm with a square taper spindle. Is 6mm going to cause any problems with my crankset? Thanks for the help!
86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
Why would you replace a new BB?
It kind of depends on how well yours might work.
Is it going to be a double or triple?
How "symmetrical" is your BB? That seems to vary somewhat. If 1/2 of the 6mm difference is on the NDS, then the DS will also be 3mm longer. That's only 1/8"! It might be an improvement???
What rings/cogs will you be using the most?
68 refers to width of the BB shell in mm, so yes, it will fit. The spindle length (107mm, 113mm, etc) is determined by the crank. If you'll be using the original crank, then it will alter the chainline. But, if you have a matching crank, then, well, it will match. Edit: since you said you bought the "frame" you may not have an "original" crank. Anyway, just match the spindle length to the crank you'll be using and you'll be good to go. The frame won't care what the spindle ultimately is, only that the threads and width (English, 68mm) are correct.
Since the spindle is shorter (107mm) than the specifications on Surly's website (113mm) I was worried about the crank arm fitting all the way onto the spindle on the drive side and being able to tighten up. I was just wondering if anybody knew for sure that this will not work so I can go ahead and order a new BB while I'm waiting for my frame to arrive. Thanks for the responses.