The
only way to know for sure the correct spindle width is to know the
manufacturer specs, because some cranksets don't follow the typical
patterns. Are you sure you have the correct spindle width? Were there
spacers included that maybe you should have used?

I wasn't aware of any of this before I took the crankset apart.
According to Sheldon, the recommended BB spindle length for my crankset
is 110-113mm. I measured the BB and was able to physically confirm the
110mm length. The spindle is the same length on either side of the BB
shell (about 21mm). No spacers were included...this is the original
crankset, unfortunately I never examined the spacing before stripping
the frame.

I just measured the gap between the crankarm and chainstay on both
sides of the frame, from the center of the pedal spindle. The
crankarms are roughly parallel with the chainstay at this point.
Here's what I came up with:
DS: 6 mm gap
NDS: 13 mm gap!!

Wow, a 7mm difference....I never thought it was that large.

Even worse...I swapped the crankarms around so that the chainrings were
on the NDS and re-measured. This time, the gaps were 8mm and 11mm (DS,
NDS respectively). Arggh! Ok. Obviously my crankarms aren't
perfectly identical, otherwise I would have had the same gap
measurement after switching them around. Something else must be fishy.


My next guess...the square taper is slightly larger on the NDS, and as
a result the crankarm cannot be installed as close to the frame as on
the DS.

I don't think I can bend the crankarms (and even if I could, it
wouldn't be accurate). I *could* try filing down the inside of the NDS
crankarm to make it slide down the tapered spindle a little further.
Alternately, I could try filing down the spindle itself. I'm not a fan
of either approach. The 7mm gap isn't a dealbreaker for me...I'm just
wondering why the gap exists, and if it is a common 'problem' for
square taper designs.

Cheers,
Dave