brandonk

I want to get a dynamo and lights for my box bike and I see there are hubs designed for 20" wheels but I didn't see any for disc brakes. Any suggestions?

fietsbob

https://nabendynamo.de/en/products/h...tandard-forks/

ones not designated '28', work with 20" wheels..

I have their splined disc version, on my Bike Friday.

for several years..

Tourist in MSN

The hub will spin faster than the designer planned if you use a full size wheel hub on a 20 inch wheel. If you flew down a mountain at high speed there would be a bigger chance of blowing out electronics from overvoltage.

Some hubs are sold in a 3 watt or 2.4 watt version. The smaller wheel would probably work better with the lower capacity hub.

Have you asked on the folding bike forum where most of the bikes are using smaller wheels?

tcs

Shutter Precision SL-9 for Centerlock brake.

"The 9 series output perfectly matches German StVZO 6V3W/20” regulation. As can be seen from the table, from wheel size 400mm(16”) to 535mm(20”), the 9 series output is designed to meet StVZO regulation."

bajajoaquin

brandonk

I certainly wont be going 40 mph, I get a serious speed wobble as soon as I hit 25 mph but that's for another thread.

The SON is over my budget, the Shutter SL9 looks like the best option at the moment but it's only 32 hole, a 36 might be better.

bajajoaquin

Looks like there's a Shimano Alfine or Deore hub that's available in 32h or 36h. Sturmey Archer has a disc-compatible model listed, but a quick search didn't show any inventory on the web. It may or may not still be out there. Sanyo (according to Peter White Cycles) seems to only have rim-brake model hubs.

I am building a 36h wheel, but with a Sturmey Archer drum brake because for some reason I like drum brakes.

What are you going to be using for lights? What kind of bike do you have? This is for my curiosity, not because it has any bearing on your question.

fietsbob

Try Real Bike Shops, and they can go to their sources ..
X-FDD is a 70mm drum, X-LFDD is a 90mm drum..

S-A link

I've had an English made X-FD for 30 years ....







....

brandonk

I think the bike is a Clamber but not sure, I take my 3 year and 3 month old kids a couple times a week 10 to 15 miles primarily on a mixed use path and a few blocks to get to the path. I will be powering front, back, possibly some running lights and horn. Dont need more than 200 lumens or so in the front but I would like to be able to have horn and headlight switches on the bars.

bajajoaquin

That's a cool bike. Mind if I ask where you got it? If it's directly from a Chinese online retailer and you don't want to get the blowback for not supporting your local bike shop, you can PM me

brandonk

I got it on Craigslist from a guy who got it at the interbike trade show in vegas. I've searched through vendor lists from the show but never could find any more info. It's a decent bike other than the shimmy it gets between 20 and 25 mph but I think sturdier steering linkage will fix that.

Tourist in MSN

Thanks for the photo, now I know what a box bike is. And now I see why someone above said you would not be going fast on a box bike. Based on that, I see no problem using a 3 watt hub that was designed for a full size wheel on that front wheel, as you probably would not be going as fast down hills on that as someone on a 700c rando bike.

I can't feel any drag on my bikes with dynohubs when the light is turned on. I know that there is some drag, but it is so minor that I often leave my lights on in daytime if I am not using my hub to charge batteries. Based on that, you might not have any real need for headlight switch on the handlebars, just leave the lights turned on. One of my LED lights (I got it on a clearance price) was built for a sidewall dynamo, it has no switch and when my wheel turns the light is on.

Two of my lights light up some different LEDs to provide better close lighting when I am going slower and brighter main beam when I am going faster (AXA Luxx 70 Plus and B&M Luxos U). I have no idea how the lights know the speed I am going, but I suspect that it would depend on the wheel RPM. If you bought such a light you might find that the close in LEDs turn off at slower speeds than you expected because you would have a higher hub RPM at slower speeds with a small wheel.

I have no suggestion for a horn, I use a bell. But a horn might need you to be moving to generate the power for it.

fietsbob

Looks like Larry vs Harry Bullitt


but w/o Shimano Steps, motor like this one ..

brandonk

It is very similar to the Bullit bike except that it has a 2 piece frame that bolts together just behind the box. I assume the 2 piece design is to cut shipping costs.

rifraf

Great looking bike OP..

I've sold my 20' wheeled Moulton now but if faced once again with a choice for a dyno-hub, I'd once again be getting a Son.

I initially got a Sondelux designed for smaller wheels, but determined that the minute extra drag from a Son28 would be my preference due to enjoying charging my phone and gps via a E-werk which would enjoy the higher output from the Son28.

Be aware that the Son whilst initially looks expensive, has a 5 year warranty unlike most of the competition which last I looked had a 1 to 2 year warranty (here in Aussie at least).

Great looking bike by the way.

From memory, better quality headlights have over voltage protection built into them.

fietsbob

In the above picture, 2nd reply, that is a 32 spoke wheel 3 cross,
the distance between spoke holes , frequency , is pretty close..

Going for Drum brales Vs Disc , I retro fitted drum brake hubs,
they adapt to rim brake frames.

So remain a possibility.. I suggest.. and gets a 36 hole drilling..