I've pretty much decided that an IGH is in my future for winter commuting. So I saw on Ebay this weekend on wheelset that had a Nexus 8, roller brakes, and a generator hub.

The front roller brake needed a fork designed for roller brakes and I was kind of on the fence if I really wanted one or not. Anyway, as the price creeped up on the wheelset, I decided to pass on it as I wasn't sure I'd use everything.

One of the questions I had was about how bright a light is possible with a 2.4 watt hub? I've been using a Magicshine and for winter I wouldn't want to go much dimmer than that. Would I be disappointed with what's available in the generator world? I'd stick with my superflash for a tail light.

If you use quality LED style headlamp eg Busch and Muller, then you should find it sufficient. You can always add an additional lamp if you feel underlight. I ride on normal city roads and some dark paths and find it plenty.
The optics are bike-specific so you get a concentrated rectangle rather than a generic circle of illumination.
With LED you should really use a rear lamp but they work OK without.
I use the higher grade Shimano dynohub (with disk brake) and its a great piece of kit.

Thanks for the information. Specifically I want something bright enough to be able to judge the contours of ice and snow covered streets. In the summer I can get by with less light.

Are you recommending using a battery powered lamp in addition to the dyno powered one? If so in my mind that kind of defeats the purpose.

Peter White has some beam shots up of different lights- most are dyno, but one or two are battery powered.

I might add: make sure that you get LED lamps if using a dynamo hub...my wife and I (me in the function of replacing the bulbs) made the experience that common bulbs were regulary burnt out with the Shimano hub on the Kettler city bike she uses for commuting. Replaced the headlamp with a Basta Sprint Steady Switch for around 13€ - now burnt out bulbs are no issue anymore, plus she is enjoying a way more brighter light.

Shimano also offers some kind of external regulator/protector for dyno hubs, but since nearly all LED headlamps features an inbuilt overload protection, why spending extra money?

I think that MichaelW was saying that if the output wasn't enough for your needs/tastes, you could augment with battery powered lights. It's going to boil down to your environment, your own night vision, and your budget.

From my own research, a DIY using halogen would be brighter and cheaper. However, a blown halogen bulb will damage the light head if it isn't turned off or replaced pronto.

want a edelux for next winter, have a e6 one halogen bulb was good for a few years,
it's replacement, 2 months.
maybe the bulb was not clean enough when I put it in?

though with a Schmidt secondary and a primary 2 halogen lamps can run off the same generator . 4.8w load. 3w generator

they are a go fast rando/brevet/audax riders choice,
to keep from out running the lights on downhill runs in the countryside ..

got 2 primaries, 1 on the bike .5M lead ,1 with a longer lead,
and a secondary, that pair in a box.

someone will like them. I'm too slow and old myself..

Compared to a MagicShine, you'll be disappointed.

I own a Schmidt Edelux and a MagicShine. The Edelux is the second-brightest dynamo headlight after the Supernova E3 Triple. It doesn't hold a candle to the MagicShine. When I run both on the same bike, I can pretty much turn off the dynamo light.

That said, I'm happy with the output of the Edelux in the dry and in less well-lit areas. Through the winter on wet, snowy, slushy, icy roads, and in the bright lights of downtown, I can only tell it's on by the reflection off the front fender. The beam of the MagicShine can get lost in those conditions too, but at least fairly close it's still discernible.

As no1mad says, your own night vision is an important variable. Mine is terrible, (runs in the family). I know of other MS users on this board who think the medium setting is overpowering. I think the high setting is weak.

On that topic, the MS's medium setting is about the same output as the Edelux.

IMHO, I wouldn't waste the time, money or effort on halogen with dynamos. I've seen them--barely. They remind me of old-school (60s and 70s) penlights.

The reason is that halogen (and all other filament bulbs) are a heater that gives off light as a waste product--the filament has to get hot enough to glow. Whereas LED are lights that give off heat (and not much of it) as a waste product. The proportions are reversed. Respectfully, I submit that those who are recommending halogen dynamo lights haven't seen the LEDs. There's simply no comparison.

You can take that Shimano roller brake off and use the wheel with a caliper brake.

Disagree with you here. I have a 1-watt Planet bike dynamo light and find it quite sufficient for night-time riding. The beam probably doesn't have enough width, but I normally commute with 2 lights these day... failover being a neat feature no matter which light set you own.

Normally, the amount of light you need is a factor of your speed and road conditions. For me, travelling less than 15 mph and actually closer to 12mph, the one-watt by itself gives me enough light to see pot-holes and other obstructions. Coupled with a blinking battery light, I think it gives ample visibility.

And... it's really really nice to know that you don't have to continually futz with a batter charger. I currently have to do this with my DIY light system on my winter bike and it's a PITA...

He specifically said halogen dynamos? The PB 1-watt dynamo is an led light just like the rest of their lineup. I'm wondering when they'll get a dynamo version of their 2-watt light.

I've got a first gen Supernova E3, an Edelux and an IQ Cyo. The first gen E3 isn't the greatest LED dyno light, but it only uses a P4 emitter. The new ones have a brighter LED with the option for an XPG R5 for even more light. The Edelux and the Cyo are almost equal in the light they put out, and I had no qualms about a 16 mile mountain descent in the rain and dark on a remote and poorly paved, winding forest service road on the 3 Volcanoes 300k last year.
The thing with good dyno lights is that you don't waste light up into the night sky or off blinding oncoming motorists and riders with a symmetrical lens. The E3 Pro, all B&M IQ lights, and the Edelux all use focused optics to put the light where you need it: On the road. If you ride in the rain and snow, this is a benefit because you don't get the eye-level reflective glare that you do from a symmetrical lens lighting up every single snowflake or raindrop in front of your eyes.

Elsewhere in this forum is a thread titled "How many lumens to see at night" or something similar. The answer: ~850L. That's two MagicShines... whoa. Yet, I agree! I don't doubt that there are people who find 200 or even 100 lumens more than enough, but as someone already said in this thread: a lot depends on what you are actually working with as per eyes. Mine need every single lumen of the single MagicShine I am running and I already have a 'Y' connector in anticipation of running a second lighthead in the near future. If that isn't you, rejoice! But know that you are the exception. Most people could use more light at nigh not less. Most people riding at night in Europe where the Busch and Mueller lights were developed don't have the kind of rural infrastructure that exists in large parts of the U.S. I ride between two cities and the unincorporated area between them has no lighting infrastructure whatsoever. I've done the "smack the hidden object in the road and wreck your tandem and crack your brand new NightRider Classic (110 lumens)" because you think you can see. I wonder how many of the 1 watt advocates are that way because they have never experienced more?

H

There are advantages to using 2 lighting systems.
Dynamo lights are always available, no battery management issues.
Battery lights can be used to carry out a bike repair in very dark conditions.

I just bought a Supernova E3 single, I am happy with it. Not as bright as some of my battery power LED lights but no batteries. I have a pile of dead LiIon battery packs, it's a small toxic waste dump. The Supernova should be upgradeable to newer Cree emitters as things progress. The E3 has a matching taillight, both headlamp and tailight stay lit for ~5mins after stopping.

I used a CygoLite Rover II LED light that ran off a battery back. The top rating was 255 lumens, but I usually used it on the medium setting which was nearly as bright but lasted a long time, let's say maybe 220 lumens. I got a wheelset with a SON hub and in October I bought a Busch & Müller Lumotec IQ Fly (with standlight) which is now mounted on my primary commuter bike. It seems a bit dimmer than the CygoLite. It rates on a different scale, at 40 lux. There is no easy conversion between lux and lumens, but I would guess the generator light comes in at less than 200 lumens. Still more than adequate for lighting my way. The B&M lights are built to German lighing standards so there is a very clearly defined edge to the lighted area. There is a lit area that is more than bright enough, and just outside that, nothing. So the thing that took some getting used to is having a tunnel vision effect since there is not really any "halo" around the main beam. When it is in the standlight mode (i.e., when I stop), it stays lit, but dims to about half full brightness. Enough to be seen by traffic. As soon as I start rolling it comes back to full brightness. I feel no discernable drag due to the dyno when I'm riding.

The limitations on the dyno light in terms of smaller illuminated area are more than made up for by its benefits- not having to mess with charging a battery and unlimited lighting time.

Since I've already passed up on the generator hub, it's been mostly an academic discussion for me but I appreciate all the information. I was concerned that the 2.4 - 3 watt supply of power was a distinct limitation that would have more of a negative impact than it appears to really have.

Still not sure I'd want to give up my magicshine (recall aside).

I thought he meant you could wire in a 2nd dyno headlight

I (finally) received an edelux in the mail (from Germany; cheaper than order from the US but v-e-r-y slow boat for December order...). The darkest depth of winter has passed, but it is pretty slick. It is sufficient for me to bomb downhill ~25mph and judge and react... well, we don't have ice contours but I can see and navigate treefall detritus, which is what we have this warm winter. It is pretty much designed to look at the road (reflectors cut off stray upper light) so judging conditions in front of you is what it's intended for.

The edelux is displacing a niterider minewt, and it is giving me better function, easier use, and I can feel more smug about being less blinding to oncoming traffic, which isn't much but hey...

Son and Shimano gen hubs can source 6W with ease, some of the newer LED lights take advantage of this.

The hub on the wheelset I was looking at was rated at 2.4 W. I wasn't interested in the wheelset for the generator, it was for the Nexus 8. It did make me curious about whether not a dynohub would work for me but I'm not at this point willing to shell out a lot cash for a new one. I might have used this one though since it was part of the package.

I have a Shimano hub and an Edelux light.

They do a fine job. I don't ride in the snow, though.

A high-powered flashlight is certainly brighter.

850L is an insane amount of light. For the average rider, that's going to be nearly 3 times the amount necessary to see at night, if the light is focused properly. I started out with a Light & Motion Solo 13W halogen system that pumps out about 290 - 310 lumens. It's not the most awesome light, and I feel like I'm starting to outrun it at 20mph, so it's not great for midnight downhills; but it works fine for visibility of rocks and potholes and critters darting in front of your wheel in the wee hours of the morning.
The reason why an 850L light might not seem bright enough is because very few companies selling high-powered battery lamps are using focused optics. This means that more than half of the projected light is being wasted. It's lighting up the sky or objects way off to the side of the road where you just don't need to be concerned. It's great if you're doing a 24hr MTB race and you need to watch for overhanging branches on a trail, but if you're riding on a road or MUP then it's not doing you any good.
Lumens are a non-directional measure of light intensity. Most generator lamps measure intensity in lux, which is a measure of intensity over a specific area (1m^2 at 10m distance). So, while the lumens may be lower on a generator lamp (usually ~400L), the lux rating is up in the 80 - 90 range, and a symmetrical high powered lamp might crank out 800L but have a lux rating in the same range because the intensity drops pretty sharply outside of the center spot of the focal point. This is how the lower-power of a generator hub manages to put out enough light for good visibility at a very long throw distance.

I have a Princeton Tec Quad LED hiking light on my helmet. I use it for spotlighting street signs in the dark while randonneuring, reading cue sheets/maps, and fixing flats. There's just no way to use a generator lamp for any of that.

You can run twin dyno lights if you wire them correctly. You won't get full capacity out of either one if they're not designed for running dual lights. Like an old E6/E6z setup will get full bright, but they're halogens and together they're not as bright as an IQ Cyo.
I was running my Edelux AND E3 Supernova for a while. It gave me about 85% capacity from each one running together and 100% from either one alone.

I ran them wired serial, because only lights set up for primary/seconday setups can run parallel. The other option if your slick with electronics is to use an inline switch so you can select either/or both lights.