mandd - back to tires - After some consideration, we've settled on Conti Gatroskins. I think Bill McCready claims these were developed jointly between Santana and Continental specifically for tandems (not sure on this). I imagine there are other tires with comparable durability.

With tires, I'm sure there's a tradeoff between "performance" and durability. I want to minimize the chance of failure. I'm sure that the Gatorskins are not the lightest or most supple tires but they have been quite durable for us. I want as much peace of mind as possible descending at 50+ mph.