Ferengii, 55k miles is truly astounding! Thank you for sharing some of your personal experience. Do you mind sharing some other pertinent information? Specific bike info would be great. You mentioned the plural "belts," so I assume you're using either a Pinion or Roholoff gearing? How heavy is your team? Unloaded riding, I assume? Anything else you care to share?

After reading about some of these failures and other experiences I've encountered elsewhere (Ryan van Duzer belt failure, ending his CO Trail trip), I'm not 100% convinced belts are the solution. Sure, I totally get the lube-free advantages. But with today's immersion & drip wax options, the typical "black grimy chains & components" can really be a thing of the past. (On one of our previous trips, one rider's drive train was immaculate. Yup, immersion waxing. He never had to do a thing to his chain during our 2-week trip.) So this is a "solution" looking for a problem. But with additional downsides. I really do not like the un-repairability of a belt. With a timing or main chain, spare links are a simple fix. And I've experienced all of ONE tandem chain failure in 30 years of road and off-road tandeming (after having blown up six rear hubs, I'm not exactly "gentle" on our tandems either). Stick or rock tossed up into our timing chain which broke it. Quick fix and we were back riding in no time. And since virtually all "belt drive" tandems are only timing belts, you're using a chain main drive, so you are carrying a chain tool & quick links anyway. With a belt, you're carrying an entire replacement in addition to the chain stuff anyway. Doesn't make that much sense. However, if I were specing a new tandem today, I'd be VERY tempted to opt for two belts and Pinion or Rohloff because of the cool factor.

And then when I hear someone boast 55k miles, I take notice! That's some MAJOR mileage out of belts!