Originally Posted by
FeartheReign
I just picked up a "kit" bike off CL
The guy sold me a mountain bike frame
with a road bike crank.
I'm sorry, but
.
Okay, just had to get that out.
I have decided that I will just buy the right BB
I know that the bottom bracket on the bike is 73mm wide
Not uncommon for a MTB frame.
and that I have to put 5mm of spacers under the non-drive
side and 2.5mm under the drive side bearings
OK this is where you lost me.
I understand that you need to
have a certain distance between
the crank arms and the frame,
but why spacers? Is this some
kind of external bearing crank?
Usually, you accomplish this with
your choice of spindle length and
tapers.
BB units (sealed bearing units) come
in a wide variety, including some that
ought to fit your BB shell. My advice:
Take it to a LBS or local bike coop and
show the whole "kit bike"
(sorry, thought I was done) to someone
that can look at it with an educated eye
for chainline. There's a chance you can
get by just with a sealed BB cartridge
for around 30 bucks (for the part), assuming
it will work with your cranks.
Good luck, amigo. I wish I could say I've
never made a similar move, but I'd be lying.
Respectfully,
Mike Larmer