Originally Posted by
jnbrown
When I look at FSA's web site it gives a chain line of 46mm for their tandem cranksets.
This is the standard chain line for a road triple.
Since a tandem has 145mm rear spacing vs 135mm for a single, it seems the chain line would be off by about 5mm.
Am I missing something here?
Also since FSA no longer makes 170mm fronts I am thinking of just buying a standard road crankset reversing the sides and installing helicoils to reverse the pedal threads. I would have to find a shop that could install the helicoils and there obviously could be some risk involved. Does this seem like a reasonable idea? Calfee tells me their BB shell is 68mm and in theory it should work.
I think you may be. I know that the web page states a 46 mm chain line, but if you go to the tech support page and look at the "tandem crank service instructions" you'll find the chain line for the tandem crank sets are 48mm with both crank spacers on the left (135 mm hub width), 50.5mm with 1 spacer on each side and 53mm with both spacers on the right side (145 mm hub width). Also, I think standard road hub spacing is 130mm.
My calfee was built with 130 mm spacing so I use the 48mm chain line. It's not perfect on the low end except in the 30 t, but it works.