Originally Posted by DaveSSS

I would not assume that you have a problem without measuring- assuming youhave a BB that matches the crank. If not, you must start with that - both a spindle length and taper made to fit the crank, not whatever the bike had on it before.

The chainring positions have not changed for a very long time. Even though the the rear dropout spacing changed from 126 to 130mm, the wider cassettes of today spread the extra width in both directions.

The common chainline specification makes little sense to me. It's always listed as 43.5mm to an unmeasureable point between the rings rather than an easily measured point to the tip of a tooth on one or both rings. With the chainring tooth to tooth spacing about 7.8mm, that makes the tip of a tooth on the big ring in the 47-48mm range and the little ring about 40mm.

http://www.sheldonbrown.com/gloss_ch.html#chainline