unterhausen

They are by far the cheapest way to get a disc compatible dynohub. Since I've never measured the draw of any of my lights, I am left wondering if they would be sufficient. I have a couple of utility bikes in the plans that would be a lot cheaper with one of these hubs

CaptCarrot

Got any links or prices?

I have the DH-S501 Alfine Dynohub. I picked it up at Rose Versand for £56 GBP and that is disc compatible. A nice hub to, and is 3W not 1.5W

https://www.rosebikes.co.uk/article/s...501/aid:333819

DiegoFrogs

I only see the DH-1N70, which doesn't appear to be disc brake compatible.

mrbubbles

Shimano 3D30 6 bolts from Germany are around $30-$40 last I checked.

unterhausen

starbike is $80

same vendor has centerlock disk compatible hubs for $40

zacster

It would be way underpowered too. Stick with 3w.

fietsbob

Why do you want only a half the typical power output?

typical headlight load is 2.4w at 6v the other 0.6w is for a taillight.

unterhausen

I'd be happier with full power, but at the prices they are selling at I am interested enough to try to find out if I need any more power. No point in having more power than I need

gsa103

A computer USB port is 2.5W. 1.5W isn't enough to even charge a phone. Considering the cost of building a wheel anything under 6W probably isn't worth the money. Most modern LED headlights are ~100 lumens/W, halogens are more like ~30-40 lumens/W. That should give you some idea.

unterhausen

the standard hubs are .5A*6v = 3W, although people who have measured it say they deliver up to 12W. I assume there is a similar discrepancy with these hubs

PlanoFuji

Standard hubs give about 3W when measured with a 12 ohm load (typical incandescent or halogen) at speed of 10mph (the standard). With that load the typical dyno hub peaks at roughly 4W output. With smaller loads (24 ohm) power is typically peaks at between 5 and 6 watts for typical cycling speeds. For speeds of 30+mph powers of 8-9 watts have been reliably reported. Useful if one has mountains to go down (not counting on that power level when climbing) or if one is able to reliably produce the ~1,000 Watts of human power to propel a bicycle at 30+ mph on level ground--in short if someone is in the same condition as elite bicycle racers.

With efficient LED lights, I would suspect peak output from the 1.5W hubs would be in the 2-3 W range (for normal riding speeds). Depending upon the light, your requirements, and your typical speeds that may be more than sufficient. Unfortunately the only way to really tell would be to get such a setup and try it. I haven't encountered any reports of how those 1.5W hubs perform. If you do try it out please post your impressions!

newredbike

Hi Everyone,
I realise that this thread is a bit old now, but I've only just come across it.
I would certainly concur with the majority of comments above, and certainly on choosing a 3w rather than a 1.5w hub. I've built 3 wheels using shimano hubs, the first was the Alfine, bought from Rose bikes, simply because I needed a black disc brake model to match the other wheel on the bike. It worked faultlessly!
I experimented with making LED lights, and had great success using Cree, Samsung and philips diodes, along with a full wave bridge and 1F super cap. The great thing about using a dynamo is that the voltage will self limit as the current increases, and as the diodes I used will accept well over an amp, which the dynamo won't provide, the diode won't blow. Making a very bright light was no problem, getting it where you want is not os easy! using collimating lenses gives a cone of light which is not ideal for a bike light *(even though lots of commercially available light do!) anyway in the end settled for a Philips Saferide which is fantastic. Rated at 2.4W as most bike lights intended for dynamo use are to allow the remaining 0.6W for the tail light.
The other two wheels were built for hack bikes using old 26in rims and really cheap (< £20 ) hubs from rose bikes, again they worked faultlessly, no cogging vibration, and lots of power ( and weight I have to say!)
Best bike has an LX hub and 11 speed hub rear, all bikes now have Philips Saferide ( owing to the fortuitous mistake of a well known mail order company selling them by mistake for £15 each! )
Sorry for the long ramble, but just to reinforce the 1.5/3W debate, built a dynamo powered charge unit with lithium battery and USB output for phone to use touring/camping last year, why have 1.5 when with no discernible extra effort you can have 3?

As of writing Rose Bikes sell a Shimano DH3D37 disc hub for £27.91....bargain

Happy cycling!

unterhausen

I never bought one of the cheap hubs, but I'm still not convinced it wouldn't work just fine for a commuter. However, anything that would see hard use is going to get a better hub, Shimano, SP or SON. I forget which project I was going to put that on. My commuter actually has two dynohub wheels, one with studs and one with summer tires

DiegoFrogs

Since I moved to Sweden, I've been using a 2,4 watt nutted Shimano dynamo hub that I bought in a cheap, $65 wheel at a hardware store with a cheap LED headlamp of unknown origin. The lamp clearly says 1 watt, but I gave it a shot anyhow.

Works good for an $80 setup. I might replace the lamp with something slightly better, but this is a bike that will almost certainly be stolen.

noglider 

Hey, that's not bad. It inspires me to start a thread on throw-together sidewall generator systems. I will start it momentarily...

noglider 

And in case you care, you can find my new thread here.