Here's a pic of my BB from an early Apex double crank set.
What I would like to know is what BB can I replace it with?
I'm going to be rebuilding with another frame with a wider tire clearance, there's no room for more clearance for wider chain stays right now without widening the crank tread so I'm thinking of a BB from a triple
seems like it's a 108mm and there is 113 and 118 available.
5mm increase in drive side width is not much though, think I may need to look for another crank like a triple that I can drop the granny ring from and grind back the mounting bolts.
i would think that we would need to know the type of BB SHELL your new frame will have. or are you planning on buying a frame that facilitates a BB that, in turn, facilitates your existing crank?
when changing frames a series of precedents must be addressed. material, clearance, size, suitiability to intended use of components, etc., etc. i wish it were simpler.
i say this because BB shells now come in various configurations as to width, ID, threaded or press-fit, etc. if it were me, i would first get the frame that i wanted then possibly address the crank issue.
or find a frame that only addresses your tire width issue and is in all other respects the same. good luck to you.
I know the frame will be a 68mm English BB, I haven't built the frame yet, it will be May/June time.
I want to build the chain stays wide enough to get a 40/45mm tire, but being 700c, I don't want to make the rear triangle extra long to try and have the tire circumference outside the chain ring diameter. That works on cast/machined/forged shapes on MTB's but the new frame material is bamboo and can't be manipulated like a block of alloy or steel