marciero

We've been using an SP dyno hub wheel on our 650B tandem. That bike has QR release and disk, but I use the 15mm thru axle version of the SP, which has 58 flange diameter (PCD) versus 52 for the QR version, and use an axle adapter sleeve. On a recent camping tour, with front and rear panniers, I noticed what I decided was spoke creaking from movement where the spokes cross. We were loaded front and rear, and though we've used this wheel for years, I was thinking it would be nice to have a touring specific wheel. I did tighten the spokes a bit on the ride, which seemed to help a bit. I could also have simply lubed the spoke crossings... The rim was an Aileron, so probably not the best choice for loaded touring. (I had recently cracked a rear Aileron) The bike also sees plenty of gravel and rough terrain. But in fact the issue with spoke movement has nothing to do with the rim, it;s purely a function of hub geometry. Lateral strength is greater with higher flange spacing and larger flange diameter. And the issue with disc dyno hubs is the flange spacing. Both the Schmidt and the SP have 50mm spacing. (Actually, the SP is only 48 since their listed measurement is to outside the flanges.) But the SP has larger flanges; the Schmidt is 54mm.

I have a nice beefy DT Swiss tandem front hub- I think that is 55mm between the flanges and 60 PCD- in the parts bin that would make a great touring wheel, but my stoker insists on dyno hub for lights. Honestly, we do fully loaded touring only in the summer months with lots of daylight. But of course, its always nice to have the lights on demand when you need them. One gets very used to having them. With both a Cliffhanger and an Atlas in the garage I had several options. I wound up taking apart the Aileron and building the SP onto the Cliffhanger.

It may be that on a fully loaded bike there is less potential for extreme lateral stress due to more conservative riding, so the narrow flange spacing is less a concern. On the other hand, we have ridden for years with this hub in extreme conditions without issue. Finally, a 650b wheel is going to be stronger than 700c due to the greater bracing angle of the spokes. In fact, the whole effect of greater hub dimensions is that they increase the bracing angle.

JaccoW

You could look at the Wide-body version of the SON dynohubs or could look at a Velogical rim dynamo as an alternative.

marciero

There is no widebody disc brake version of the Son. That is because with a standard 100mm fork dropout spacing the extra width is taken up by the disc. The Velogical is intriguing, but with a few possible drawbacks. They are designed to work on a brake track, so disc specific rims without may not be ideal. The attachment is less than ideal from a design as well as an aesthetic standpoint. They are reportedly loud, or at least very noticeably audible. I am a little biased too because at this point I am pretty heavily invested in hub generators with about six of them on different bikes, including two tandems.

JaccoW

Hey I get it, I have hub dynamos on virtually all of my bikes (and the ones that don't are going to get one).