Originally Posted by
Paluc52
all tandems the builder makes come with 175mm crank arms for the captain, regardless of the size of the tandem. That sounds crazy. What am I missing?
That is, in fact, crazy. Both riders should have crank lengths that are comfortable for their physiology. A proper bike fit is critical for a comfortable ride. If the riders find that their cadences don't line up, then it's okay to experiment with different crank lengths, but I'd always recommend shorter cranks to avoid injury.
Our tandem has 172.5mm cranks in the front and 165mm cranks in the rear... because that's what we use on all our single bikes.