fietsbob: I wish I could afford a Phil Wood...I'll probably be looking at something like an IRD.
Originally Posted by
peugeot mongrel
If you are going to set it up single on the outer ring position you want the ring 3mm closer than it's position as a double, more like 109. If you get the spindle too short on some frames using a double spider the inner offset will hit. Like Bill said you can always use a spacer to help.
Well, I'm not actually trying to match the original chainline for this crankset, which would have been 43.5. I'm trying to line up the single ring with my Sturmey Archer IGH in the rear, which is at 47mm. Luckily, the original outer ring location for the 7402 was about 46.5/47.
So if the original outer ring on the 7402 was about 47mm with a 112 BB with 3mm extra from the asymmetry, then going by my calculations and the info the other posters have given, a new, symmetrical 115mm BB would give me the 47mm chainline I need (give or take about .5mm).
Would you guys say that is correct?