Imzimmer:
Agree the tandem can work 'perfect' on workstand. But then add the weight of 2 bodies to the bike on the road, and it needs a bit more fine tuning!
Minor things like cablehousing, fraying cable, bent der., worn teeth on chainrings/cassette, etc all can cause these annoyances.
Pedal on TWOgether!
Rudy and Kay/zonatandem