# dynamo hubs



## zahgurim (Aug 12, 2005)

I'm looking to build up a new wheelset for the new touring/bikepacking rig I'm building up over the next little bit.

I'm really considering to use a dynamo in the front, to have the ability to be more self reliant and not needing the grid/hotels to charge batteries every so often. 

I think there'd be no problem with the dynamo for road touring, as riding speed is fairly quick. 
What I'm worried about is the slower speeds while mountain bikepacking. Is that an issue with the dynamo? 
How are people finding the use of dynamos out on the trails?


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## eredinger (Apr 16, 2009)

There are a few good threads on the light section of this forum. Here's one:

http://forums.mtbr.com/lights-night-riding/generator-lights-how-do-they-compare-878841.html

Good luck!


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## sonoranmtb (Oct 3, 2013)

I've been running the Shimano Alfine for a couple year now. Works good, simple, clean set-up. I run an Exposure dynamo-specific LED light and the thing works great.


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## woody.1 (Jun 10, 2008)

If you haven't been over to bikepacking yet there is some great threads there as well.

Hub dynamo and electronics thread.

and

ewerk or plug ii - opinions?

and of course Peter White's

Lighting systems

Woody


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## Welnic (Feb 6, 2013)

I've been using a SON28 hub with a Supernova E3 Pro for over a year for commuting. It is perfect for that, it is so nice to just always have your light ready to go. I have no experience with the USB charger systems. But at some point I plan to build up a front wheel for long range bikepacking with a dynamo hub. I don't think that you would have any problem charging things even with the slower speeds involved riding off-road. If you are pushing your bike at walking speeds, then the light does have an annoying strobe effect, but with my setup at least traveling at around 8 mph puts out smooth light. Once you have the system charged up then you can stop and the light stays on. When it is charged you can ride at very slow speeds and it doesn't strobe, but I have never done this for extended periods and don't know if it will do this indefinitely.

If I was going to do a setup right now, I would go with whatever SON28 hub worked for my front wheel. I would use a Schmidt Edelux II headlight, and some kind of dynamo taillight. I would get a Plug III for the charging duties. And I would have some kind of battery operated headlight that I could put on a helmet. Hopefully something that could be turned down low enough to use in camp.

I did most of my original research and bought my system from Peter White.


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## azgoat (Aug 9, 2012)

Another dynamo hub option is the SP Dynamo:
SP Store

I just bought the PD-8X, but have not used it yet. After much research, I decided it was the most efficient, cost effective option. Probably going to order a Supernova E3 Triple 2 for the front light, and the E2 Tail light 2 for the rear. Looking to get the Plug III for charging.


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## zahgurim (Aug 12, 2005)

Yup, I was thinking of the PD8X myself. I like the 15mm axle.


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## Lars_D (May 24, 2011)

I have about 4000 miles on my SP dynamo--my wife and youngest daughter also have them on their bikes. All are trouble free. My lights are B&M which are very high quality and trouble free.



azgoat said:


> Another dynamo hub option is the SP Dynamo:
> SP Store
> 
> I just bought the PD-8X, but have not used it yet. After much research, I decided it was the most efficient, cost effective option. Probably going to order a Supernova E3 Triple 2 for the front light, and the E2 Tail light 2 for the rear. Looking to get the Plug III for charging.


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## Giel (Jan 16, 2011)

zahgurim said:


> Yup, I was thinking of the PD8X myself. I like the 15mm axle.


FYI: SON also has a 15mm TA model


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## Butchcantswim (Oct 6, 2013)

Dynamo vs Solar or? 

Looking to charge the "normal" day to day electronics we tend to travel with (Iphone) and run a light during overnight camping trips and normal day to day family cycling. I don't intend to cycle for more than a few hours after dark. 

Initially I was really excited about the Dynamo hub option, however the price of $150-$300+ for the hub and $200-$300 for the light made me start to ask myself "why". I can get a small Goal Zero solar panel that will charge my iphone and be useful on other hiking or outdoor activities $80. 

As for the light, I can get a REALLY nice Night Rider brand battery operated light for the $300 price point that will work for about 2 hours on high, much less the lower settings and then potentially recharge it with the above mentioned solar panel. 

The Dynamo hub idea seems really cool, just wondering if I'm missing something. Maybe it's more of a cycle commuting thing where you routinely bike after dark and need a steady light source....

Butch


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## Aushiker (Sep 27, 2007)

zahgurim said:


> What I'm worried about is the slower speeds while mountain bikepacking. Is that an issue with the dynamo?
> How are people finding the use of dynamos out on the trails?


I have a Shimano Deore XT DH-T785 dynamo hub on my Giant XTC 2 and I tour with that, e.g., the Munda Biddi Trail.










Now whilst I personally would not get another Shimano hub I don't have an issue using a dynamo hub off-road touring.

I use the hub mainly to keep my GPS charged up and/or or my PedalPower+ Super-i-Cable charged up for off bike charging. I tour with a Apple iPad for example.

Andrew


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## bikeny (Feb 26, 2004)

Butchcantswim said:


> Dynamo vs Solar or?
> 
> Looking to charge the "normal" day to day electronics we tend to travel with (Iphone) and run a light during overnight camping trips and normal day to day family cycling. I don't intend to cycle for more than a few hours after dark.
> 
> ...


It really comes down how you want to use it and how much power you need. Running a relatively high power battery light at night, and then trying to recharge it (as well as other stuff) from a solar panel will be tough. Most bikepackers will be riding during most of the daylight hours, which means you need to rig up the solar panel to the bike somehow and have it aimed at the sun. This is tough, considering roads and trails are not straight lines, and there are also trees and other stuff to block the sun. That's assuming the sun is even out! I have not tried one, but from what I have gathered, the solar panels need to be aimed pretty well to get any output, and even then, it takes a while to charge anything.

With a dynamo hub you always have power to charge things & to light your way (assuming you are moving). The ultimate setup would be a nice Dynamo hub, and nice dynamo light, one of those USB plug setups that hooks into the dynamo hub, and then a small AA battery pack that charges via USB. As you ride during the day you can charge your GPS or phone or AA battery pack, then at night you can charge other stuff from the full battery pack. Yes, that's an expensive setup, but if you are going off the grid for a while, it's the best way to go to have power for lights, phone, camera, GPS, etc.

Then again, if you are doing S24HO or family trips with a bunch of down time, a solar panel may work fine.

Mark


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## rifraf (Dec 22, 2012)

Isnt the solar gear, just something else to have to carry with its bulk and weight?
On my tours, the daylight hours are for riding and not sitting around waiting for a slow charging method to work.
I consider my Son28 hub and E-werk combo (and Edelux and Philips Lumiring tail-light), pretty much a one off expense and fit and forget solution.
Whilst things are sitting around charging off the bike, I think they are a prime target for theft should you turn your back on them.
This was a major consideration of mine having had my wristwatch stolen from a campground shower once when I thought it well hidden in my shoe just outside the shower curtain.
I'm yet to meet someone who regretted forking out for their charging investment for their gps/phone and lighting.
I'm so impressed with my set up I'm investing in another one. A dynohubbed single wheeled Extra-wheel trailer with its own E-werk and cache battery to charge my laptop and photography gear whilst hauling water in a couple of 10 liter Ortlieb waterbags.
Not snobbing your solar gear if it works for you, but merely pointing out it has some limitations compared to a fit and forget solution.
Good luck with the purchase decision.


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## pimpbot (Dec 31, 2003)

zahgurim said:


> I'm looking to build up a new wheelset for the new touring/bikepacking rig I'm building up over the next little bit.
> 
> I'm really considering to use a dynamo in the front, to have the ability to be more self reliant and not needing the grid/hotels to charge batteries every so often.
> 
> ...


It would be slick as heck if somebody had a way of making a Dynamo hub with no drag when there is no load. Seems to me one could then rig up a switch to engage the hub when descending, to charge batteries, then run lights off the batteries the rest of the time.


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## bikeny (Feb 26, 2004)

pimpbot said:


> It would be slick as heck if somebody had a way of making a Dynamo hub with no drag when there is no load. Seems to me one could then rig up a switch to engage the hub when descending, to charge batteries, then run lights off the batteries the rest of the time.


You mean like this:

SP 7 series dynamo hub

Although I think most agree that's it not worth the added weight and complexity. With no load, the drag on the current dynamo hubs is very low and hard to notice when riding.


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## rifraf (Dec 22, 2012)

I can honestly not discern any drag either when my hub is under load (lights switched on) or not.
Some people claim they can.
I cant and its not because I'm a strong rider, because I'm not.


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## mosquitos (Feb 14, 2004)

Aushiker said:


> Now whilst I personally would not get another Shimano hub I don't have an issue using a dynamo hub off-road touring.


I'm considering myself to get a DH-T785, you got any trouble with it?


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## pimpbot (Dec 31, 2003)

rifraf said:


> I can honestly not discern any drag either when my hub is under load (lights switched on) or not.
> Some people claim they can.
> I cant and its not because I'm a strong rider, because I'm not.


Well, the reason I brought it up is because the hubs I've messed with all drag a bunch even with no load. That kinda bugs me on an armchair engineer kinda level.

Since all energy has to be consumed, I'm wondering where the drag energy is going, because it is not going to power a light if it's switched off.


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## pimpbot (Dec 31, 2003)

Butchcantswim said:


> Dynamo vs Solar or?
> 
> Looking to charge the "normal" day to day electronics we tend to travel with (Iphone) and run a light during overnight camping trips and normal day to day family cycling. I don't intend to cycle for more than a few hours after dark.
> 
> ...


Heck, for that matter check out the Lumina series NR lights. I run a Lumina 650 on the helmet, and I ran one on the bars before I got my dual beam MiNewt700 fixed. Very impressive for $125, and that was a year and a half ago. Now, $125 gets you the Lumina 700 which is even a bit brighter. It runs for 2 hours on high and 5 or 6 on low. Honestly, low is plenty of light so I run it on low most of the time.


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## Aushiker (Sep 27, 2007)

mosquitos said:


> I'm considering myself to get a DH-T785, you got any trouble with it?


No trouble with it but I can feel the drag particularly at the lower speeds mountain biking whereas with my SON I don't. I guess it comes down to $ and what bothers you  I am hoping my new SP PD-8 will be the nice comprise between the two extremes.

Andrew


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## mosquitos (Feb 14, 2004)

Aushiker said:


> No trouble with it but I can feel the drag particularly at the lower speeds mountain biking whereas with my SON I don't. I guess it comes down to $ and what bothers you  I am hoping my new SP PD-8 will be the nice comprise between the two extremes.
> 
> Andrew


Thanks for the input.
As shimano stuff is quite cheap here in Japan, it will be good enough to try the dynamo hub for touring/bikepacking


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## jan_nikolajsen (Oct 28, 2011)

There was some mentioning of solar panels earlier in this thread. We toured with a Brunton 14 watt Solar Roll on a 2 month trip. The panel is used on our boat, but very lightweight albeit bulky. It charged our camera and phone.

Did it work? Yes, it did, with these caveats:

Don't underestimate the time needed to acheive a full charge even on very small gadgets. 
Can't practically be used while riding, even w a trailer.

Those two issues combined makes it a rest day/late start application only.


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## Welnic (Feb 6, 2013)

pimpbot said:


> Well, the reason I brought it up is because the hubs I've messed with all drag a bunch even with no load. That kinda bugs me on an armchair engineer kinda level.
> 
> Since all energy has to be consumed, I'm wondering where the drag energy is going, because it is not going to power a light if it's switched off.


On Peter White's site he measured a SON28 at 1.6 watts of drag at 30 kph with the lights off, and 7.2 watts with the light on. When you turn the wheel by hand you can feel the resistance rise and fall as the poles of the rotating magnet go by the wire coils that are fixed to the axle. Even when the light is off the magnet is inducing current in the coils and this causes some drag. The extra drag comes from creating these eddy currents, and like most things it ends up as heat.

The SON28 still has the lowest drag with no load. I think that other hubs are now close to the same drag if you are running something. I really don't notice the drag of the hub, I even just leave the light on during the daytime. I do notice that it is a 28 lb touring bike compared to my 18 lb road bike though.


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## alias (May 9, 2005)

I have been running the supernova / pd 8 dynamo for three years with zero complaints. I did also use a small solar array on last summer's tour through Scandinavia and can say that solar while travelling is just not fast/efficient/good enough. I recently installed The Plug lll on my Fargo and it's so much better than dragging the solar stuff around.


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## Butchcantswim (Oct 6, 2013)

Looks like the dynamo hub is the more consistent option for use while on the move. I appreciate the input!


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## Couloirman (Sep 17, 2010)

anyone successfully using a dynamo hub for rough trail/singletrack riding? I was debating taking mine on the colorado trail this summer but am wondering if it is up to the task? I know it works well on tour divide type dirt roads, but trail riding is a whole different ballgame. I have an SP PD-8x with 1000 lumen klite for reference.


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## rifraf (Dec 22, 2012)

pimpbot said:


> Well, the reason I brought it up is because the hubs I've messed with all drag a bunch even with no load. That kinda bugs me on an armchair engineer kinda level.
> 
> Since all energy has to be consumed, I'm wondering where the drag energy is going, because it is not going to power a light if it's switched off.


I'm seriously amazed.

I've used the original dynohub Sturmey Archer GH6, SonDelux and now Son28 and I've never been able to notice any drag, either with lights on or off with any of them.

In fact I often dont turn the lights off during the day due to not noticing them being on (due to no drag).
The leds last for many thousands of hours so I'm not worried about wearing out the lights so am ambivalent about my usage.

My original use was as a commuter just using lights but now I use an E-werk with cache battery to keep my Edge 800 and cell phone topped up.


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