# Hub generator powered light



## dstorjoh (Aug 4, 2010)

I am interested in the lights powered by a generator in the hub. I did a search on this Lights and Night Riding Forum here on MTBR, to no avail. I know I have seen them on here before.

I am really looking for a break down on the performance/drawbacks of the units on the market. Then also a comparison of the light provided by them compared to a battery powered unit. What kind of watts do these generators put out? How hard are they to pedal (is it worth one gear of resistance or much less?)? Are they suitable at all for the trail or just commuting or just novelty?

Thanks


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## roadrider1 (Mar 20, 2012)

Interesting question - particuarly from an engineering standpoint and am looking forward to any info that others may have.

The power output on a hub generator would be low at low speeds (like when I usually have my lights dimmed - low lumen) and the output would be high when I'm bombing down the trail using the light on full power (high lumen).

Hard to beat the weight of new lithium batts though exept if you were bicycing across the Kalahari and there is no power to recharge (and you lost your portable solar panel)


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## Lugano (Jan 16, 2011)

I use both battery lights and dynamo lights. Battery lights are brighter but the dynamo lights aren't bad at all, especially the best ones from Busch & Müller as well as the Schmidt eDelux. They are better suited to commuting or road usage in my experience. The resistance of a good dynamo hub is negligible and they are surely not a novelty if for no other reason than that you never think about the battery. The best ones are good enough to use alone but they are not as bright as good battery lights. 

I have a Supernova e3 Triple which claims to be one of the brighter ones putting out a supposed 800 lumens. It's probably half that based on my experience with some battery lights. However, they do produce full brightness at about 8 mph. 

I plan to get a B&M Luxos light when they become available this fall.


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## cue003 (May 6, 2011)

Look for dynamo lights that have a reserve setup (called standing light) so that when you stop the light can still be used for a couple minutes before shutting off. This reserve also helps maintain brightness when you slow down as well.

Exposure Lights just came out with a high powered dynamo light for 2013. The popular choices that I have seen in the past are from Lumotec/Busch and Miller, Schmidt, And Supernova. Others are starting to pay more attention to dynamo lights and getting in the mix.


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## dstorjoh (Aug 4, 2010)

cue003 said:


> Look for dynamo lights that have a reserve setup (called standing light) so that when you stop the light can still be used for a couple minutes before shutting off. This reserve also helps maintain brightness when you slow down as well.
> 
> Exposure Lights just came out with a high powered dynamo light for 2013. The popular choices that I have seen in the past are from Lumotec/Busch and Miller, Schmidt, And Supernova. Others are starting to pay more attention to dynamo lights and getting in the mix.


The reserve setup would be key. Also with regard to all of the postings, I noticed nobody has mentioned the Shimano dynamos, is there any reason for this?


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## dstorjoh (Aug 4, 2010)

roadrider1 said:


> Interesting question - particuarly from an engineering standpoint and am looking forward to any info that others may have.


You may have seen this, http://www.vintagebicyclepress.com/VBQgenerator.pdf,in the "hub dynamo" Wikipedia article under references. It is somewhat technical, if you don't like the technical stuff, just read the closing paragraphs, where it summarizes the findings. Incidentally within this article, I somewhat found what I was initially looking for.


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## Lugano (Jan 16, 2011)

I use a Shimano dynamo. It is excellent. No issues at all. I don't know which model but it is the most current high-end model they have.


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## znomit (Dec 27, 2007)

dstorjoh said:


> The reserve setup would be key. Also with regard to all of the postings, I noticed nobody has mentioned the Shimano dynamos, is there any reason for this?


Many km on road and MTB with shimano dynamo hubs. No problems whatsoever. 
For the MTB you probably want to supplement with a low powered helmet light for the slow stuff.


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## dstorjoh (Aug 4, 2010)

znomit said:


> Many km on road and MTB with shimano dynamo hubs. No problems whatsoever.
> For the MTB you probably want to supplement with a low powered helmet light for the slow stuff.


On your MTB, are you traveling over rocky or rooted terrain?


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## znomit (Dec 27, 2007)

dstorjoh said:


> On your MTB, are you traveling over rocky or rooted terrain?


Now and then I hit the trails, yep. Its also survived a decent dunking in the river :thumbsup:


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## roadrider1 (Mar 20, 2012)

dstorjoh said:


> You may have seen this, MUST HAVE 10 POSTS TO SHOW LINK!! in the "hub dynamo" Wikipedia article under references. It is somewhat technical, if you don't like the technical stuff, just read the closing paragraphs, where it summarizes the findings. Incidentally within this article, I somewhat found what I was initially looking for.


Thanks - interesting review. I think for the weight, the LED/lith batt combo is hard to beat. If I lived in a city and my bike spent all of its time outside (i.e.: Amsterdam, Tokyo) the dynamo makes sense, but for mtbing I'll take my Gloworm X2.


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## AWDfreak (Jan 28, 2007)

Are you guys talking about hub as in, connected to the wheel, or connected to the drivetrain?

I always found it odd that it seems (at least due to my lack of knowledge) that nobody has developed a generator directly connected to the crank (or cassette), as the pedal speed seems to be more of a proper solution to keeping a light charged rather than relying on wheels speed, just as in automobiles (alternators are connected to the crankshaft, not the wheels).

An MTB-tough light with a crank/drivetrain-mounted generator would definitely get my attention, but it seems batteries are still the norm in the bike-light market...


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## mattthemuppet (Jul 16, 2004)

that'd be fine for a fixie, where you have to pedal all the time, but on anything with a freewheel there'll be a lot of times when you'll be going really fast and not pedaling at all


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## Maximus_XXIV (Jun 7, 2009)

Peter White Cycles has tons of info on their site.

Check out NH-T10 Bottom Bracket Dynamo for one connected to the crank.

Wheels are better because they always spin, even when going downhill.


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## robdeanhove (Dec 8, 2005)

dstorjoh said:


> I am interested in the lights powered by a generator in the hub. I did a search on this Lights and Night Riding Forum here on MTBR, to no avail. I know I have seen them on here before.
> 
> I am really looking for a break down on the performance/drawbacks of the units on the market. Then also a comparison of the light provided by them compared to a battery powered unit. What kind of watts do these generators put out? How hard are they to pedal (is it worth one gear of resistance or much less?)? Are they suitable at all for the trail or just commuting or just novelty?
> 
> Thanks


You didn't do an exhaustive search! I've postred on a few threads on MTB dynamo lights. There's a good amount of info on this thread HERE, which links through to a more detailed description of my MTB setup HERE

Dynamo and a very good standlight - essential for off road









There are genuine off road dynamo options available now. The best I'd say is the Exposure Revo, a bright and very long lasting standlight is what makes this one stand out from the crowd, and what makes it most suitable for technical off road, rocky, rooty and twisty singletrack. See the link on the Exposure website HERE

Exposure Revo:









Hope that helps!


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