I have an older MagicShine (P7 emitter) and like it except for the battery pack and less than robust wiring/connectors. I also have one of the cheapies (from Wallbuys not Amazon but likely very similar if not the same) and find the cheapie is much more "throwy" and may have an edge on overall output (probably from having an XML rather than a P7). The cheapy has even less robust wiring (didn't think that was possible) and 3 rather than 5 modes. I'd say good riddance to the SOS mode but it would be nice to have a middle output level.

The batteries seem to be the biggest issue with either of these. They are a 2S2P sealed pack with questionable cells and no way to balance them. In my opinion, you need to have a good understanding of the "do's and don'ts" of Lithium Ion batteries before buying any of these lights.

Maybe, but there are already laws requiring bikes to have lights and ride with the flow of traffic that aren't enforced even if they could be used for harassment.

You may have to try it to see the advantages. All the maintenance and adjustment of battery lights that you are currently doing may not be obvious until you stop doing it. A dynamo system is more durable and more worry- and maintenance-free. Nothing to remember to do. No toxic waste, either. I just jump on and go. Works every time, for as long as I'm riding, not based on a battery's capacity.

So the advantages of a dynamo hub would be no batteries to worry about forgetting to charge or replacing batteries, lights just work.

Are there other advantages?

What about the disadvantages? I have often thought the tradeoffs were not worth it for me, though I haven't really looked into Dynamo for lights seriously, so many of my concerns may not be valid or real disadvantages. Please prove me wrong (or right). The items that come to my mind include

1. Added weight - How much do these really weight though? I assume its minimal impact for most commuter bike and weight is in the hub.
2. Friction from dynamo - I assume there is some, is it noticeable?
3. Cost - Certainly more expensive short term...not sure about long term depending on how reliable they are
4. Brightness - The only dynamo I have used was on a bike share bike, and they are not very bright (be seen lights). How bright can I get? Can I control the brightness?
5. Running wires - Wires weigh something, and need to be run through/on the bike. Granted some battery lights have external packs and wires, but the small all in one rechargeable units do not have the complications of wires, strapping extras on, etc.
6. Theft risk - can the light be easily remove/stolen off a bike? One thing I like about the simple all in one USB lights is I can easily remove them if I need to lock up my bike. Could someone steal the light part of the dynamo easily?
7. Do lights stay on when I stop at a long light, etc? For how long?

Appreciate feedback on any other advantages and my perceived disadvantages. Who knows, maybe I will wind up shopping for a dynamo hub based on the responses.

1. I guess they add about a half pount.
2. No, I don't notice the friction. Really, and I tried to notice it.
3. What's the question? The cost is $150 or more for a complete setup, including dyno hub, front light, and rear light. Reliability and durability exceed that of any battery powered system. Not only is there no toxic waste, there's no battery leakage to muck up connections.
4. The new headlights are brighter than before, and half of that is not due to output but due to brilliantly (pun intended) designed optics which are normally not found on battery lights. I can see well enough to go 20 mph or faster on a totally unlit road. Do you need better than that?
5. Wires don't weigh a significant amount. You can use one wire and use the bike frame as ground.
6. Normally, you bolt these on. It would seem like a bad idea to leave them on in an area where bike cannibalism is high, yet I see them here in Manhattan, and no one is messing with them. I can't explain it, but it's good to be wrong on something like this!
7. They have a capacitor built in, so they stay on for a few minutes, long enough for a traffic light or whatever.

First, with modern rechargeable batteries, there is no battery leakage unless something catastrophic has happened to the battery. The cells are usually isolated from the connections with welded tabs between any connected cells. Welded tabs mean that leakage wouldn't have an effect on the connections anyway.

With the exception of the (now) rarely used NiCad batteries, rechargeable batteries aren't "toxic" waste. They may be hazardous but that is different from "toxic". They are far less toxic, and hazardous, than many household items people use daily. If you use Drano, gasoline, ammonia or bleach, you are using substances that are both more toxic and more hazardous. A bottle of wine is probably more hazardous (flammable) and toxic (the buzz from alcohol is from low level poisoning) than a rechargeable batteries is...as long as the battery isn't NiCad.

While the optics of lights used with generators can be well designed, there is nothing that says they have to be. You could take the same headlamp and power it with a battery or you could wire up a Magicshine to a generator if you so desired. There is nothing particularly special about generators that they need to come with special optics.

That capacitor is a super capacitor that is an electrochemical device similar to a Li-ion battery. They are about as hazardous as an Li-ion battery when it comes to disposal. That brings up another point, generator systems...lights, dynamo, control circuits, etc....have more electronics on board and, as such, have slightly higher amounts of hazardous materials when it comes to disposal than a normal LED light. The circuitry is likely to contain cadmium, mercury, lead and other toxic metals. The units are small so the amounts are small but these materials aren't just hazardous. They are toxic as well. If you are going to compare hazards, compare the hazards of both systems.

And compare them fairly. I am the owner of 8 bicycles and if I wanted to outfit all 8 of my bikes with generator systems, I'd have 8 times the materials in the bikes. I really can't see the point of having one generator system and trying to move it from bike to bike since portability isn't one of the reasons you use generators. I'd have 8 lamps and 8 hubs with 8 times the toxic materials in the circuitry. Compare that to having a single LED lamp and a single Li-ion battery...if we are assuming the same output of light. I have multiple lights but I don't have to have more then one.

To be fair:

A dynamo is really designed for urban usage which usually indicates:

1. Only one bike is owned due to space constraints.
2. Bike is left outside year round due to space constraints.
3. Bikes should be a get up and go proposition including lights, fenders, wheel locks, racks and bike pump all integrated.

You're the odd ball in the bicycle ownership spectrum with eight bikes.

Also, for what it's worth, I would think that one set of 4x28560 (or whatever the MS runs on) would be far worse for the worth than 8 dynamos and bike lights which can easily be reclaimed as scrap/conductive metal and/or recycled.

A capacitor that gives a couple minutes of light is a deal killer for me. If I get a flat at night, I need sufficient light to change the flat, which could take 15 minutes or longer in the cold. My battery powered light will run for hours on a lower setting, not a couple minutes. On high, I'll get 1.5 hours, but that would be way too bright for changing a flat. Also, having the light on my helmet makes seeing the wheel all that much easier, because the light is aimed exactly where needed.

What do you dynohub guys do for light in that situation? I'm guessing you walk or call for help. That's not always a viable option where I ride, which is pitch black and can be a couple miles from civilization. Even if I'm riding at dusk and don't need light, I'll bring along a light in case of a breakdown.

Most people don't get a flat.

A Schwalbe Marathon Plus tire in 42cm width in an urban area should be good for 10000km puncture free.

Wanna ride a road/race bike with less than 42mm, then deal with the hassle.

The right tool for the job

I don't know where you ride, but there is no such thing as a flat-proof pneumatic tire. I've had valves fail, and flats from all sorts of things on tires ranging from 700x23 to 26x60. Flats are a contingency every bike rider needs to be prepared for. What is your plan? Hop in a cab or call a friend?

To take a break from battery/dynamo flat protection flame wars and return to the original topic...

For seeing road debris, I've heard that a fork-mounted light works well. The larger difference between the viewing angle of your eyesballs and your light, the more you will be able to see debris thrown into relief by shadows. (Conversely, if the light source is inside your eyesballs, you will see no shadows at all)

Live in a metro with adequate transport (i.e. subways, commuter trains and buses that take bikes).

Even in rural northeast England, there are 5 train stations between home and work (in 10km).

Thanks for the feedback, I appreciate getting some of my concerns addressed. Sorry if I derailed the post a bit off topic into a dynamo/no-dynamo flame war, it was not my intention.

I don't entirely agree with the no toxic waste part - it is still an electronic device with hazardous materials used in it that need to be disposed of properly, same as any electronics, batteries, etc. Now if they are reliable, they should last longer then most rechargeable solutions so may produce less waste in the long term, but its probably such a small difference between this and other modern rechargeable batteries I don't see this as an advantage or disadvantages either way.

I don't think a dynamo makes sense for any of my current bikes, I do think if/when I get a more dedicated commuter/utility/touring bike I will consider dynamo options for convenience, while continuing to use battery lights for my other bikes.

If I go with a dynamo on a future bike, it would be a replacement for my handle bar mounted light. I would continue to use my helmet mounted light (USB rechargeable battery) which will work for fixing a flat in the dark.

Any recommendations for how to fork-mounted lights? Seems like most lights I see are designed for handle bar or helmet use. Do you get odd shadows from the wheel with this set up (seems it would give a shadow for half of the coverage area).

I often keep a light pointed further down then normal (either handlebar or helmet, have tried both ways) to see debris better. The tradeoff is that this light does not go as far forward to light my path ahead (but the second light can point further forward). I even tried two handlebar lights, one lower power facing down and one facing forward.

Shadows is not (much) dependent on angling the light on the handlebar, but moving the light further away from the eyes/line of sight.

Does your fork have any braze-ons? I've seen cylinders that can screw into a rack/fender mount and basically simulate a tiny handlebar. Also Problem Solvers has some interesting solutions. And of course there's always the ghetto solution of interlocked hose-clamps.

As for shadows from the rim itself being in the light path, probably unavoidable. BUT, if you have a front fender you could try to attach a light to the top of it.

cyccommute, it appears that you really have it in for people who like dyno lights. Or you enjoy telling people they're wrong. Or something.

I also have eight or so bikes. I'm not putting dyno lights on all of them. I AGREE that it would be dumb. Just because it doesn't make sense to put them on eight bikes doesn't mean it's a bad idea to put on one or two bikes. Not all bikes deserve the same treatment, at least among my bikes.

I'll retract my assertions about toxic waste. Never mind about that.
What does this even mean? What are you trying to say? My observation is that all current model headlights made for dynamos have these refined optics. Don't even ask me why, but they do. Virtually none of the battery lights have this feature. Again, don't ask me why. I can guess, but I won't. Yes, it's possible for a dyno head light to have bad optics, but that is not the case, so your hypothetical argument does not show that dyno lights are a bad idea.

It's also possible to power a light with crude optics with a dyno. I have no idea why you would do that. Basically, it's possible to do a lot of dumb things, but what argument does that help? Thank goodness not all bad ideas you come up with will be attempted, right?

No, a generator is designed so that you can use a bicycle light without a battery. Period. It has nothing to do with space constraints or bicycles being left outside or the ability to get on and ride. Even in exalted Germany or Holland, I think you'll find a bike that has every thing you listed that is integrated into the bike would be hard to find. Some of those items are important but many aftermarket lights, fenders, racks, locks and pumps are more reliable and better than OEM equipment.

I'm not nearly the odd ball in terms of number of bike owned as you think. I personally know many people who have more than 8 and there are many, many forum members who have as many or more bicycles than I own. You have 2 which is how it starts. Why did you buy a second one? What possible purpose can it serve?

You got them there Two minutes isn't a lot of time. And if the flat is on the front wheel, you couldn't even pick up the bike and spin the wheel so that you could get light.



No tire, short of absolutely awful solid tires, is immune from flats. Flats are a random event and can happen due to a variety of causes. Even Marathon Plus tires aren't immune from flats. Even in places where goatheads don't exist there are lots of things that can flat a tire. I've driven a 16 penny nail completely through a tire on a dirt road 30 miles from civilization and had flats due to the steel strands from belted tires.

True,but it's not unusual for people to own multiple bikes. Multiple mounts are much cheaper than multiple dyno setups,and really in most cases you can just use one set of mounts;additional sets just save time in swapping between bikes.

That's ridiculous. Even Marathons aren't 100% flat proof,and you can't control your environment. You can ride past a spot for years with no issues then suddenly get a flat because there is some construction going on or an accident left debris. Plus,while it may be rare,tire failure happens. I've seen tires have a sidewall go bad within a month due to either a manufacturing defect or the fact that they were old,un-rotated stock.

In DC,non-folding bikes are not allowed on Metro(subway) during certain times,and there are large areas without any stations. There is also a large contingent of cyclists who regularly use our MUP system.

Cities differ,and not everyone can/wants to live in a city.

Problem Solvers has a couple different mounts,as well as other companies.

I use a helmet light, which has the fairly big advantage that it shines the light where I'm looking. When I'm riding out in the boonies, I almost always have a backup battery headlight too, but I think I would scream if I had to use it to change a flat or perform any other mechanical task. I'm fairly conservative when it comes to walking home, nothing is foolproof. I've had a number of battery lights fail on me, didn't like it.

I've tried a low mounted light and absolutely hated it. Every shadow was elongated and exaggerated. Small rocks have huge shadows. I could see potholes but only the edge. The interior of the pothole was just an dark well that could be inches or feet deep. There was no way of knowing.

I would suggest a wider angle flood light or a diffuser to illuminate the road close to your bike. However if the light is too close, you won't have time to react to any road hazards. You could do the same as you do now if you had a helmet light. You can illuminate the road close to the bike by simply tipping your head down rather than having a light that is permanently aimed at the road.

Yes, I should have said before, I've never tried it myself, only heard of using fork-mounted lighting, and mostly I've heard that people that tried it didn't like it.

Somebody must have liked it though; I've got a nice 531 Falcon from my dad with a dedicated lamp braze-on on the right arm of the fork (for left-handed English roads). I always thought it would be cool to find a lamp that screwed right in there (not just a modern lamp that mounts onto an accessory that screws in there).

For the last couple of days I've moved my light to the fork (something else on the handlebar). I haven't been plagued by the problems that cyccommute mentions - my only issue is that the wheel blocks off some of the light. Other than that I kind of like it, and haven't decided whether I'll keep it like that.

northeast England is quite far from city ... unless you're counting areas with 100k people a city, which is laughable.

i provided my response to a personalised question. feel free to extrapolate it and put words in my mouth, if you so wish

Above the fender seems like a good alternative. for lower light to get the road better. I have seen bikes with dynamo lights there. Do they make fenders with a easy way to attache a light like this? This isn't something i will likely try with my current commuter (which is really my road bike that I started commuting on), but might try when i get a more dedicated commuter bike.

I can see how elongated shadows could be annoying, but I would probably still supplement this with a helmet light which would reduce this.

Then again, maybe mounting the light lower isn't the solution to my "problem" at all, but some other combo of lights and light angles to both illuminate close in front of me and far away from me effectively - hey wait, this is actually getting back onto the OP topic on front light set up!