I was mostly considering economical alternatives to using $40.00 worth of 9-sp chain to replace a synch chain. I hadn't considered the possibility of borrowing for repairs, and I probably should have mentioned that it was for road use. I've never trashed a synch chain on the road, but I have destroyed the primary chain. On the other hand, after owning an off road tandem for a short time, I can see how damage to the synch chain might be a concern.

Rick