I got to wrench and ride a bit this morning, even though it's winter. The tandem is at our country place. I changed the (captain's) saddle to a firmer one. I had a gel saddle which was too squooshy.
I also took a look at the gearing. The bottom gear is just about right, but the top gear is too low. So I counted the teeth on all the cassette cogs and chainrings. No wonder the top was too low. The cassette is 13-34, and the crank is 28/38/48. That gives me a bottom of 22 and a high of 100 inches. Tandems need a wider range than singles. I see I can get a 60T chainring. Oh, but I forgot to notice if the chainrings have ramps and pins. How much of a hassle will it be if I need them and don't have them? The entire drivetrain is Deore XT, but I don't know what year. I put a non-pinned crankset on another bike, and the front just wouldn't shift from middle to big.
There do not seem to be 7-speed Hyperglide cassettes with 11T cogs, so I think I'll stick with this cassette. There are others just like this one, so I can replace it when it wears out.
I didn't take any pictures, so here is a picture from the summer. The bike is a Burley Zydeco.
