Originally Posted by organicmuch
I have a 1960s Peugeot bike with a cottered bottom bracket that I want to convert into square tapered. I was told that this could easily be done just by replacing the spindle with a square tapered one. I measured the dimensions of the cottered spindle and found that the center, or B in this image from Sheldon Brown
was 56mm. If I buy a spindle with the middle length of 52mm, im think it would not work because the space between the bottom bracket shell and the spindle thing (dont know what its called) is too far apart for the loose bearings.
How do I solve this problem?
Buy a new french threaded bottom bracket? (or maybe just new bearing cups?)
or will the 52mm spindle work with the bottom bracket cups I already have?
First, if you decide to replace it with a
sealed cartridge unit from Velo Orange:
I have one I just ordered for a PX-10
overhaul, and while I cannot testify with
regard to its longevity, it appears to
be a very high quality product.
If you want to simply replace the spindle,
whether your 4mm shorter spindle (between
the cone surfaces) will work depends on
how much adjustment you have to play
around with in your adjustable cup. As
long as you have enough thread left to
install and tighten the lockring after you
adjust the bearings, you're good.
There used to be a number of various
square taper spindle replacements available -
which is probably when whatever you read
was written. Now, unless like me you have
access to a pile of used parts or a bike coop,
the choices are more limited. Perhaps
someone else will post a suitable source for
a guaranteed replacement.
But if you really like the bike, plan on keeping
it for a while, and are going to replace
with a reasonable quality crankset, consider
the Velo Orange sealed unit.