28h dynamo wheel strong enough?
 

After agonizing over which dynamo hub to get for 2 weeks, I finally settled on the SP SV-8. Unfortunately, my retailer only has the 28h version in stock. I was planning on doing a 32h build, but a 32h hub would take 8 weeks to ship.

This would be paired with a DT Swiss R460 rim, and I'd run 32 or 28mm tires on it. The purpose is randonneuring, and some of the roads around here are a little rough. I weigh 170lbs, maybe 175 occasionally.

Will I be okay with 28h, or should I spring for 32? I can find another retailer with the 32h version in stock, but mine is selling 'em for $30 less than other places. (Yes, I'm cheap.)

your plans or riding style , is unstated..

I have 28 spoke wheels , but they are 406 20" (2 on my bike trailer )

and a 16" on my Brompton.. (I have the original & one made around a Schmidt New XS dynamo hub..



8 weeks? you ordering from Asia? bring as you say, cheap ,
that the case why not just get a shimano dynamo hub wheel off the peg
with a rim of modest cost like Sun CR18?



good luck..




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700c wheel to be used for brevets. I don’t know about my “style,” but I’d prefer something reasonably durable. I’ve never broken a spoke or anything, but then again, I’ve never had a 28 spoke wheel.

I can get the R460s for about $10 more than the CR18, and it seems to be better in just about every way. (This coming from someone with two sets of CR18s.)

IDC sells 24h 700C wheelsets with that hub: https://www.intelligentdesigncycles....speed-wheelset

As Bob mentions, how you ride will determine whether that's enough spokes. I built my dyno wheel with the 32h version and wouldn't blame you if you held out for the same.

DT Swiss spokes (2.34 / 1.7 / 2.0 or 2.0 / 1.8 / 2.0) with brass nipples and properly stress relieved...you should be fine.

=8-)

My CR 18 is rolled down to 406 20"...

boxing the bike to fly to Paris, for P-B-P, shipping & handling , may be the most stress..

After the first couple years' riding, the extra $30 cost for a 32 spoke wheel won't matter any more.

When randonneuring there is usually no support like being on a tour. I would go for the higher spoke count even thinking about 36 double butted spokes.

Good point. Luckily I just found a 32h hub someplace else for only $10 more than the original place. So I went for it--better safe than stranded with a taco'd rim two hundred miles from my destination (or fearing something along those lines).

The SV-8 hub is designed for smaller wheels (400-536), which spin faster at a given speed. Power output will be reduced slightly if used on a larger diameter wheel. This may not be significant, but if you also plan to power your phone or other devices it may be iffy. The PV-8 is recommended for the larger wheels.

This^^
I just installed a 700c wheel I built with a PV-8 hub. There's still a bit of flickering until the speed gets up to 7 or 8 miles per hour. I have a 406 wheel with an SV-8 on my folder, which works well with that size wheel.

I’m just using it for a front light, no rear, no charging. Not too worried about power output.

That was my rationale for using an SV-8. It's not a bike I have to ride at super-low speeds, so it works out. :)