JONG BB question

[davieboot]

I've taken on a project building my first bike from scratch. All seemed to be going well until I came to a issue with my bottom bracket/crankset compatibility. My crankset documentation says it needs a spindle length of 113/118mm. So my question is, which do I get, or do I split the difference with a 115mm. I know it has to do with getting the chainline right, and a friend told me it might depend on my seat tube diameter (which is 1 1/4" (31.8mm)). What size bottom bracket do I need?

[mntlion]

what bike?

[shirk]

Bottom braket width is dependant on the frame. What frame do you have?

What cranks do you have? This will determine the type of bb.

Square taper? Octalink? Isis? x-type? Mega-exo?

[davieboot]

I'm building off of a nashbar touring frame. I know that I need a square taper, 68mm bottom bracket. It is just a matter of the spindle length.

[davieboot]

and the cranks are sugino xd300s.