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28h dynamo wheel strong enough?

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28h dynamo wheel strong enough?

Old 05-14-19, 12:52 PM
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samkl 
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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.)
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Old 05-14-19, 01:03 PM
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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..




...





...

Last edited by fietsbob; 05-14-19 at 01:09 PM.
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Old 05-14-19, 01:29 PM
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700c wheel to be used for brevets. I donít know about my ďstyle,Ē but Iíd prefer something reasonably durable. Iíve never broken a spoke or anything, but then again, Iíve 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.)
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Old 05-14-19, 01:35 PM
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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.
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Old 05-14-19, 01:41 PM
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Originally Posted by samkl View Post
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.)
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-)
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Old 05-14-19, 01:44 PM
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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..
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Old 05-14-19, 02:25 PM
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After the first couple years' riding, the extra $30 cost for a 32 spoke wheel won't matter any more.
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Old 05-14-19, 04:46 PM
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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.
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Old 05-14-19, 10:02 PM
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Originally Posted by davidad View Post
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).
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Old 05-16-19, 12:24 PM
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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.
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Old 05-16-19, 12:39 PM
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Originally Posted by Moe Zhoost View Post
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^^
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.
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Old 05-17-19, 01:04 PM
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Originally Posted by sweeks View Post
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.
Iím just using it for a front light, no rear, no charging. Not too worried about power output.
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Old 05-17-19, 09:52 PM
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Originally Posted by samkl View Post
Iím 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.
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