how are bb spindles measured? chainline question
I'm trying to figure out a workable chain line for my motobecane fixed project. I rebuilt the swiss threaded bb and am not sure on two things:
I know the shell is 68mm- but how is the spindle measured? The spindle has square tapers, then threads after the square tapers (on either side). do i measure the overall length of the spindle? Or from end of taper to end of taper?
The bearings / cups / lockrings are in very good shape after my rebuild- but I'm not sure if the spindle length will be compatible with a 42mm chainline. I plan on using the bargain track wheel from nycbikes.com. Can anyone advise me on how to select cranks to make this work, or if it is possible to find different spindle lengths for my existing bb?
on modern cartridge BBs, spindle length is measured end to end. in the old days of cup 'n' cone BBs, spindle length used to be measured end to end, and then center to end. you can still measure cartridge spindles this way, of course, but you can't really change them out, and they don't make a bunch of different 110mm BBs with varying drive-side spindle lengths, so it's pretty much pointless.