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.