Originally Posted by
uspspro
Strange... the timing chain is not that slack on the flats, nor is it now after the ride. It has well under 1" of deflection. Is this caused by rider power differences?
You haven't been married very long, have you?
I would never suggest that as a possible cause.
Instead, consider boom tube flex. See if you can find a photo with you both out of the saddle, but with the other pedal forward.