would like to replace the 170 mm rear crankset on my Cannondale 2007 road tandem with 175 mm cranks. I assumed that I would be able to swap the front LHS 175 mm crank with the rear LHS 170 mm crank, buy a standard RHS 175 mm crank to replace the 170 mm RHS rear crank and put the RHS rear crank on the front RHS. So I would end up with 170s on the front and 175s on the rear.
The spec for this tandem says the BB (I assume both front andrear are the same) is a TruVatiV ISIS GigaPipe SL which I had assumed used a similar setup to Shimano Octalink. However I believe that this is not the case and the axel is part of the RH rear crank and the same istrue for the LH front crank. In which case, I won't be able to do what I had hoped to do as described above.
Could anyone please confirm twhether the axel is indeed integral to the RH rear and LH front crank arms and if so, suggestions on what I could do?
Also, and more importantly, there doesn't look like there is a great deal of clearance between the LH rear crank arm and the rear stays and was wondering whether anyone had successfully fitted 175 cranks of some description to the rear of a J/L 2007 c'dale tandem or could tell me whether there is enough clearance. The rear stay is not straight.
If I can put 175 mm cranks on the rear, is it possible to remove the axel from the LH front (if is it part of the crank) so that I could fit it on the rear and what RH arms are compatible with this BB?
Apologies if any of the above are obvious but I'm blind and so can't see pictures online which would probably answer most of the above.
Thanks in advance.