jtg1

I just wanted to ask if anyone on here either has or has used those dynamo hubs that Peter White cycles has on his website. It would seem to be a good thing to have, ie; no batterys. Are they as reliable as he states or is the drag much more significant than he states?

What are your thoughts?

genec

Sanyo used to make a great top of the wheel generator... the main advantage of which was being able to disengage it entirely and remove all load.

Everything I have read about wheel hubs says that the load is minimal, but still exists.

I too would love to have a redundant system on my commuter/touring bike. (using a bottle battery as the main lighting system)

Eggplant Jeff

One common complaint is that with a dynamo hub, as soon as you stop moving, your lights all go out. Not a great thing when stopping at a stop sign at night.

spider-man

I run a Shimano generator hub on a Raleigh road bike, and it is terrific. There is no noticeable drag with the light switched on, and the light is much brighter than battery-powered systems I have used in the past. Plus, no batteries.

I use a Lumotec headlight that has an LED standlight. The LED stays on for about 10 minutes after you stop. After that, though, all lights do go out.

Machka 

Many Randonneurs use the dynamo hubs with great results .... if I could afford one, I'd get one.

You can get a light that will stay lit even when the bicycle stops, and even if you don't have that option, you would be riding with a battery back-up light anyway, so you'd just switch it on.

ajay677

I've got a Schmidt SON hub and light. Great product! No noticeable drag and the light illuminates the road bautifully. These systems are for road use only as there is not much light thrown to the sides. The lights are precisely focussed and put the light on the road exactly where you need it. Lights are available that have a stand light feature. Light will be emitted, even if the bike is not moving.

Brian McDonough

For many years now I was using a 6v-3w small generator hooked up to a voltage regulator for charging rechargable batterys and that charged energy is used for My Garmin II GPS. It works quite well . now I use a hub gererator instead.The Number 30 hub generator by shimano is holding up quit well for over two years now without problems. I ordered from Peter White.

carlton

I don't own a hub style dynamo but was able to test ride one. The SON had two Smidt headlights and worked great for road riding. The beam was bright and very concentrated in front of the bike. Lit the road up even on a totally dark road or one that had some streetlights. As others have stated this style doesn't put out enough light to the sides to be effective for offroading. I have owned a sidewall generator and it had a lot of drag when engaged and was hard to properly adjust for proper tension to the tire and slipped every time it got water splashed on it. I do not recomend sidewall generators.


QUOTE=Brian McDonough
For many years now I was using a 6v-3w small generator hooked up to a voltage regulator for charging rechargable batterys and that charged energy is used for My Garmin II GPS. It works quite well . now I use a hub gererator instead.

Tell me more about your charging system and regulator.

fsor

I have a schmidt SON and E6 light. They work very well and have a good rep. for reliability. I would not commute without some kind of battery powered light. I have had one flat in pitch dark circumstances and that convinced me! You could never sell a schmidt by passing the hub around...the notchyness is unbelievable when just turning the wheel by hand. Obviously, almost all of the force required in turning past a pole position is returned on passing the pole. The drag in actual use is not a matter of concern to me. I have not used the shimano but intend to put one in my commuter use.

Rev.Chuck

I use the Shimano Dynamo(Two years it is much cheaper and easier to service than the White. The White does work well, I have a randoneer that swears by them and has done Paris brest Paris and the Boston event as well.
The, no light when stopped, is a little annoying but I keep a back up flasher on the bar.
The Shimano can be switched off, then it just runs a LED, the load is much lower and it still puts out a noticeable flash. When in the "on" position it puts out a decent amount of light, tho not as much as battery system.

PaulH

I've had a Shimano for three years and 7,500 miles. Dead reliable, unaffected by rain and snow. No noticable drag.

Paul

jtg1

Thanks all. It seems that so many recommend other lights yet I read about how reliable these are I am suprised more are not using them.

Brian McDonough

QUOTE=Brian McDonough
For many years now I was using a 6v-3w small generator hooked up to a voltage regulator for charging rechargable batterys and that charged energy is used for My Garmin II GPS. It works quite well . now I use a hub gererator instead.

Tell me more about your charging system and regulator.

Suprisingly not too many electronic engineers cater to the Bicycle field therefore the Bicyclist relies on what the Bicycle industry offers . I have an Elementry knowledge in electronics and start to experiment on the bicycle generator over 5 years ago and came up with a reliable system that can keep my devices such a GPS going forever without batteries . and even charges my cell phone and countless other uses, in fact when I first started, I hooked up a boombox and I had music whenever I was bicycle and what the advantage was is that it used no batteries that would come loose or cause static evertime I hit a bump on the road.

The bicycle generator is in reality is an alternator just like what you have in your car but much weaker and must be what is called recterfied by using a bridge recterfier . to produce DC current from AC current now this is still unaceptable DC current because it is unregulated so you must in addition use a small regulator from radio shack called a 317 voltage regulator. along with a couple of 1000 capacators and resistors. and thats about it.

carlton

QUOTE=jtg1

Thanks all. It seems that so many recommend other lights yet I read about how reliable these are I am suprised more are not using them.

I think more people don't use them because of the cost of building up a new wheel when adding them to a existing bike. The other main reason I see people not using them is alot of the people who ride offroad cotinually badmouth them. The offroad riders need more light and these systems don't provide enough so they think the dynamo lights are no good. Not taking the time to realize they are suited to city and road riding. Sort of like driving your Baja offroad racer down a city street with lights so bright and burning the paint off the vehicle 1/2 a block in front of you. Really looks and sounds cool but not nesassary when normal car headlights will do. I noticed a few remarks about not having light when stopped with a dynamo. This is easily solved by using the right headlight. Some lights have a built in capaciter and will burn for several minutes after stopping. Shimano's new Smover system with built in capaciter will burn even longer. As mentioned above a small LED battery light will also provide light when stopped as well as providing some light in case you needed to make fix a flat or something. To me they are worth the price and my next bike will have a hub dynamo either the SON or the newer shimano with ultegra level bearings.

carlton

Thanks for the reply Brian.

Are you saying the dynamos are AC current then have to be changed to DC then run through a reguator? Do you think your sytem could charge a battery like the type used in bike sytems say like niterider? If it wouldn't completely charge the battery would it at least provide enough juice to greatly extend normal run times?

DCCommuter

Charging a battery with a hub dynamo is problematic. On the one hand, the power output of the dynamo fluctuates depending on the speed. On the other hand, the charger has to carefully monitor and adjust the charge voltage and current to assess the state of charge of the battery and avoid overcharging it. So you're trying to match a variable power source to a variable power sink.

An alternator with voltage regulation via the coils, such as is used on a car, produces a near-constant voltage regardless of speed as long as it's turning. That would help a lot with this problem, but I've never seen such a unit for a bike.

I think a better bet is forgetting about charging and using the dynamo to extend battery life, and the battery to back up the dynamo. If dynamo output is above battery voltage then the light runs off the dynamo, otherwise it runs off the battery.

Michel Gagnon

I am using a Schmidt + Lumotec Oval Plus on my touring bike and tandem, and a Shimano NX-30 (the old one, not the "new and improved one") with a round Shimano on my commuter. I recently upgraded the lamp on the touring bike to a Schmidt E-6.

The Schmidt is simply unnoticeable when off and almost unnoticeable when on. The Shimano has "some" drag when off, but it never prevented me to ride 1500-2000 km per year on that bike. After 4 years of year-round service (including in the snow and salt in Winter), there is now a lot of resistance in the hub, so I bought a new Shimano hub to replace it. Let's say that 55 $/4 years is not too expensive.

For city illumination, I think the round or oval Lumotecs are enough. However, to ride on unlit or almost unlit roads, the E-6 is simply amazing. One word about the Oval Lumotec: its beam is slightly better than that of the round Lumotec, but the standlight feature is not impressive. I carry a cheap Planet Bike Beamer, which offers about 20-25 hours of light with 2 AA batteries (I use rechargeables); the Beamer provides a useful standlight, has a flashing mode and is useful to fix a flat in the dark or to read a story to the kids in the tent.

geo8rge

My understanding of physics is there should be no drag if the lights are off. Is this true?

DCCommuter

Even with no electrical load there will be residual magnetism that will impose drag.

fsor

I have only seen the "standlight" in the lumotec. It would not suffice for changing a tire at night. The Schmidt E6 lamp is very satisfactory for city driving....I use battery powered tail flashers and really do not feel the need for a standlight. I do, however, use a secondary headlight to keep Murphy from providing me with nightime flats...works like a charm. I also like to point it (secondary lamp) off to the side as it helps to pick up the eyes of roadside skunks.......I feel the need to avoid them, I am sure that my coworkers would be unhappy if I got sprayed.

Brian McDonough

I am charging two 6 volt batteries the ones that are used in small racing cars and are rated at 1000ma and they are hooked up in series to produce 12 volts and really works great . so I feel the nightrider battery could be charged without any great problems. The thought of overcharging a battery by a 6v-3w
bicycle generator is not a problem . The problem and the solution to the problem is in the circuit that the regulator is built into. as the battery starts to charge it produces what is called a back electro magnetic force that will eventually burn out the regulator.so the solution is with a small diode across the regulator. to block this force.Also make sure you put a heat sink onto the 317 regulator. for added protection so not to burn out the regulator when you go at high speeds. with your bicycle.

L Dude 7

Has anybody used a dynamo to power a GPS? From what I've read, (https://www.nomad.ee/micros/etrex.shtml), it appears that the eTrex is smart enough to determine if an external power source is present, and then switch to it instead of batteries. So, it seems that it could be connected to the power source, and then when moving, it could run off the dynamo, and then when not moving, off the batteries. Is this feasible?

Paul L.

I am another happy customer of the shimano hub. With a double K2 LED light on the front I have plenty of light that doesn't get washed out under streetlights.

2 K2s + lenses = $24
AC Buckpuck LED driver = $19
Home depot parts = $6
Shiman 3n-71 hub = $90

$139 for one awesome little light that goes as long as I do. (Well, the rim and spokes added $50 to that but I could have used an existing rim).

wahoonc

I just acquired a bike with the Shimano hub on it, prior to that my only experience had been with the older SA Dynohubs. With the Lumotec light it is a much better rig than the one I was using, amazing what 50 years in technological advances can do With the Lumotec and the Shimano I can actually get enough light to see at a fast walking pace. As far as no lights when stopped, the tail light is the Toplight Plus with the LED stand light, and I use a Planet Bike Super Blinky. For the front I use a second bar mounted cheap LED light. It serves the purpose as a marker, and a light for roadside repairs. Eventually I may get the Lumotec with the standlight, but that is a ways off. Neither of the hubs creates enough drag to worry about, it isn't like I am competing the TDF or something I have used battery lights in the past, but it is great to just hop on the bike and not have to worry about whether I have my lights or not, are the batteries really charged up, and do I need to head home before dark...Nope!

Aaron