Hello, I have a suntour xc pro crank and a cheap chin haur bb on my Bob Jackson world tour. I've done a bit of research and discovered that the xc pro BB (which I'll never find NOS) is 125.5. Right now I am running a 122 bb with no granny ring. I'd like to eventually get a phil wood BB in the appropriate length.
My question is this: were the xc pro BB's symmetrical? I see a lot of extra room on the NDS, and I worry about knee issues if I put a lot of miles on this bike. If the xc pro bb's were not symmetrical, does anybody know the lengths on either side relative to the center of the bike?
Here an exploded pic of a XC Pro bb, this particular one being a 73-122.5 ==>
(of course only assemble it with free moving balls, not with those fitted in a ring)
I can tell it is perfectly symetric. Also other XC Pro bb's I have, including MicroDrive ones are perfectly symetric. And if they weren't, it would probably be for compensating for something in the XC Pro crank design ...and you use XC Pro cranks.