I’d be interested to hear thoughts on a new wheelset choice.
Specifically, which current hubs people favor. I’d like to have the option of 11s road or microspline drivers if possible.

I am going to get a set of 650b wheels for our co-motion, mainly to allow for wider tires for some light/medium gravel.

The bike uses rim brakes, and currently has DT540 hubs (10s) which I like for their durability and ease of maintenance. The website shows HG driver, but doesn’t say if it’s 11 speed road or mtb (10s).

Thanks,
Joel

Spinergy might be good ones to take a look at. House of Tandems in TX are very helpful.

Are you currently running 700c wheels? If so, how are you going to overcome the issue of the rim brakes not working with 650b wheels?

I don't know. I must be missing a gene or something but I can't see the attraction of junking a perfectly good set of wheels and spending possibly hundreds of dollars for a new wheelset that will get used <shrug> what, a couple or more dozen times, if that? I don't think I am giving bad advice to suggest the o.p. determine the widest tires that will fit in their co-motion, obtain them and call it good. All the tandems in our club run 28mm clinchers. The ride leader messed up one ride and we found ourselves on a stretch of gravel that went on for three miles. It wasn't fun, but we all made it through. Unless I way miss my guess, the o.p. could possibly get 10mm bigger than whatever they have now, and that should be plenty good enough.

My current wheelset is the original 700c dyad rims. These have served well but will need to be replaced soon in any case due to brake track wear.

the widest tires possible on this frame with 700c is 32, which we have. (The limit is clearance at the chain stays).

As to why 650b? It would allow 42mm wide slicks. If you’ve only ridden 28’s, you might consider trying wider tires. Better ride and not slower. If I was buying a new bike, that’s what I’d spec.

on our bike, the easiest solution will prob be a new fork to take the 650b wheel and keep the same geometry. Our local frame shop can braze new canti studs on the stock fork pretty reasonably, so might do that.

just trying to figure out if there’s a new/better hub out there. I’ll prob just build the 650b’s on the original dt540s. They’ve been bombproof so far.

Yes, wider tires are better. For years we were limited to 32mm wide on our older Santana. On our newer tandem, we went with 26", to allow much wider tires and also to simplify packing into cases when travelling. We now always tour on 50 mm (with fenders), it is so much better. For the small fraction of people that wish to race on smooth roads, yes 28s are faster. But for most people seeking fun on whatever road surface is presented, wider is better.

Thanks for the input. That helps with the decision.

Agree with the rationale for wider. Smaller wheels are lighter, offsetting the weight of larger rubber. Also stronger.

Tadej Pogacar won the TDF on 30mm last year and 31mm the year before. So I’m not convinced 28s are faster in any circumstance.

42 is the sweet spot for us, and 650b will make that work.

The braking choice should dictate what rims you can run, there are a lot more options if you have disc brake mounts as rim brake rims are becoming scarce