Hello everyone,

I sure could use some help wrapping my mind around how to upgrade my bb and crankset.

I ride a Mercier Kilo tt. According to Bikes Direct, the bb is 68 x 108 mm. The chain line is 43.5mm.

I understand that the 43.5mm chain line is measured from the center of the bb to the center of the chainring. According to Sheldon Brown that's not a standard chain line for a ss/fg.

It's easy enough to find a 68 x 108mm bb for an upgrade, but the spindle length is only half the equation since the crank spider will place the chainring in maybe the wrong position for an even chain line.

Is there a solution for shopping for the right crankset/bb to ensure I'll have picked the proper spindle length for the chosen crankset or is it a matter of putting spacers in to compensate for buying a setup that throws the chain line off?

Any help would be greatly appreciated.