Dyno- Hubs, which model is best?

[Stuart]

I intend to build my front wheel up with a dynohub and would like advice from any member who has experience of these dynamos.

[Raph]

I've got the schmidt - it's excellent. It's pokier than most side-driven dynamos, and there must be voltage limiting inside it cos it doesn't blow anything down hills. I use it with a 2.4W halogen bulb, without a rear light (the rear's a separate LED light). It's about the same with a 3W bulb (the theoretical output), but takes a higher speed to get to full brightness. The drag when switched off is absolutely insignificant, and hardly noticeable when switched on. On another bike I have a Nordlicht which gives a fraction of the light (well, at a fraction of the price...) and I've used various Soubitez and Union and Axa dynos and none were as good. The only one that was brighter was the Sanyo Dynapower which I don';t think is made any more, and that used to need at least 15mph to get to full brightness (steep climbs were done in near darkness) and it blew bulbs for breakfast unless you fitted a separate voltage limiter.

The Schmidt adds quite a bit of weight to the bike, but if you do a lot of miles at night and can't be bothered with keeping track of charging batteries, then I reckon it's superb.

PS also had a previous version of the Shimano Nexus dynohub for a while, and that was similar to a side-driven one - quite bad vibration and drag at low speeds whether on or off, and similar weight to the Schmidt, I think. I don't know what the current model is like though, it might be better.

[Raph]

Forgot to say, the Shimano cost about £60, but I think even at that price it's worse value for money than the Schmidt at £130-odd.

In fact, if you're interested you're welcome to it for nothing cos I've still got it - but even for free I don't think it's as good value as the Schmidt! Especially considering you have to build it into a wheel.

[andrew_s]

I've got about 50000km of satisfied use out of my 2 Schmidts so far.


Info from Aktiv-RadFahren magazine article

Values
a) Volts at 10kph
b) Efficiency at 20kph
c) Drag at 30kph (Watts, lights on)
d) Drag at 30kph (Watts, lights off)

Schmidt28 a=4.9 b=60 c=7.2 d=1.4
Shimano NX32 a=5.1 b=48 c=8.6 d=7.2
Shimano 3N70 a=5.4 b=54 c=7.6 d=2.2
Enparlite geared a=4.7 b=28 c=16.9 d=0.3
SRAM a=5.0 b=59 c=6.4 d=6.1

(SRAM i-light not available in UK, AFAIK)

[andrew_s]

Correction for 3N70:- a=5.0

[Raph]

I assume Shimano NX is the Nexus I've slagged off - I repeat, I'll happily post it to whoever wants it, for nothing. Sounds like the new one is totally different and close to the Schmidt in use, especially the very low drag when off. Does anyone know what it costs?

Another consideration is whether you can change the bearings. I'm not sure if you can on the Scmidt - I haven't had to think about that yet.

[andrew_s]

The NX30 has a dynamo section that's onlt about 40% of the hub width. There was previously an NX10 with a full-width dynamo section like the Schmidt.
The new 3N70 is about £65

[Raph]

I must have had the NX10 then. I wouldn't say it was utterly pants, but suffice it to say I bothered to take it off and rebuild the wheel with a Schmidt costing £130 odd and I'm much happier.

[rogerzilla]

The Schmidt is the best. The Shimano DH-3N70 is not too far behind, and the DH-3N71 (just released, goodness knows when it will appear in UK shops) is better still.

Me? I'd save for the Schmidt.