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22

The electric parts of the dynamo hub don't care. They're an AC generator and there's no concept of reversing the flow with AC. However, the mechanical bits of the hub itself can be a problem. You don't indicate which manufacturer/model dynamo you have. The great majority of hubs are constructed such that they are expecting the wheel to turn in a certain ...


11

There are standlights, which are essentially supercapacitors combined with LED headlights. They're designed to be charged from the dynamo while riding and give you a few minutes of extra lighting when stopped at a stoplight. However, all the ones I know will self-dissipate after a while, so they're useless for your purposes of starting off the day with full ...


8

Bottle dynamos aren't actually as bad as often claimed. They are usually cheap, lightweight, have less resistance than people think and zero resistance when not in use. There are some bad parts, though: Most of available dynamos are complete rubbish and won't last in use. High quality dynamos have been superseded by hub dynamos and battery lights. ...


8

Reelight do something similar but opposite: they mount magnets on the spokes and the light and coils on the frame. This demonstrates that it's broadly possible. You'd need to mount the magnet on the fork or seat-/chain-stay with a coil and light on the wheel. This gapped dynamo arrangement won't be very efficient, but wheel lights don't need to be as ...


8

Reverse pulses at low voltage probably won't damage the LED, but the COB (chip on board) that gives the flashing modes might not be able to cope with the full reverse voltage. The problem is that the hub dynamo is more accurately a constant current source, and will supply about 500mA. One common trick is to run two 6V lights in series off a hub dynamo, and ...


7

When checking a Dynamo system, there are 3 basic items which need confirmation: Power Supply: Is your dynamo producing power? Checking this requires a multimeter, preferably with alligator clips on the wiring, and to spin the hub. Or there are specific tools, as well. Wiring continuity: Are all connections tight? Are there any breaks/shorts in the circuit? ...


7

Here's a guide for overhauling a cup-and-cone low-end Shimano dynamo: https://dl.dropboxusercontent.com/u/34057344/Overhauling_Shimano_Dynamo_Hubs.pdf The main caution from that article concerns the connector-side cone & nut and the aluminum wire underneath them: Using your finger to prevent the plug assembly from turning, break the lock nut from the ...


7

The truth is, that the vast majority of bottle-dynamos are utter crap. They are built to be attached to BSOs (BSO = Bike Shaped Object, a bike that's built so cheap that you can hardly call it a bike), allowing the BSO to pass the legal checks (needs to have working lights compliant to law), but are simply not designed to cope with low temperatures and/or ...


6

I've used such wheels for some time on my hardtail. First with V-brakes back and front, then switched to disk brakes as the frame allowed both types of brakes. I cannot say that I have experienced any issues with such wheelset. My centerlocks hubs even came with plastic covers on disk mounting surfaces so that they would not become dirty when no disks are ...


5

According to this page yes, the hub is discontinued and is no longer available @armb's assumption may be true. They stopped making IGH's and dynamo hubs for the same reason, at the same time. I-light had such a small market share that it didn't even earned to be mentioned.


5

There aren't many repair or maintenance parts on a Shimano dynamo hub. At best, you can replace the sealed bearings (on the units that have them) or adjust the cones on the ones that don't. The most likely failure mode in your case is that either the 1) main electrical leads have oxidized; 2) or an internal wire has broken. My guess is that since your ...


5

Thought I should update this just in case anyone's been looking (probably not so much in summer!). I got a good deal on a B&M Cyo plus. This has a switch and standlight. The rear light connection is switched AC. I bought the cheapest standlight equipped rear light I could find with no switch. The front light comes on and off with the switch as you'd ...


5

Speaking in terms of past few decades to current generator hubs and lights, mostly they are interchangeable, with some qualifiers and exceptions. Almost all current hubs and lights are based around 6 volt, 3 watt, and can all work together. Usually the deal is your hub is going to have its own connector type which it will probably come with, like the two-...


4

It sounds like you have a bottle dynamo. Many are constructed poorly and have matching short lifespans. Typical failure modes are: Friction wheel is made of cheap plastic, rubber, or pot metal -- and wears down, breaks, or flies off The wiring was done by drunken lemurs and breaks off inside No sealing against water/dust/salt and it corrodes to pieces The ...


4

Planet Bike Blaze Dynamo has it.


4

The downside is that the disc brake bike won't get the advantages of a disc-specific rim, like greater structural efficiency (how strong it is for its weight) and ding resistance due to no brake track, and the rim brake bike won't get the advantage of a dishless wheel, which is greater total tension and more strength. Building such a wheel does mean the ...


4

You could. If you were a hobbyist, it'd be simple enough to hook a DC motor to act as a generator, smooth the output, boost-buck it to the right voltage, and use it to charge a deep-discharge lead-acid battery. From there, you could either use it to charge your USB equipment or get an inverter to run some lights. I would not hook it into your mains, the ...


3

Situations when the weight of whole bike + cargo (+ maybe a rider?) is concentrated on a small patch of kickstand's clamp and when a small dynamo clamps the same seatstay are really incomparable. In the first case it's a thousand Newtons of stress applied to a piece that was not supposed to be pressed in that direction, and for dynamo it's about five Newtons ...


3

There are four things you need to know: Almost all (99%) of bicycle "dynamos" are in fact AC alternators and they produce alternating current (3~6 VAC) with a current limiter (usually 1A max). The frequency of the AC varies by speed. Most dynamos tie one of the output legs to frame ground (neutral). The dynamo manual will tell you which, but if you don't ...


3

If your rear light will not come with standlight function, so (in the options I know) the front light with standlight will not "turn it on" at the rear light. Such lamp is AXA Echo 30 Auto Steady. It has cable to connect it to the hub dynamo connector and output for the rear light. But don't get misleaded. This output only transmits current when dynamo is ...


3

After some pondering, I ended up buying a new hub, hoping to replace the center part without the need to re-build the whole wheel. I share here some information that might be helpful: even the new Dynamo showed electric contact between the two terminals, so they are NOT isolated from each other and checking that is no proof the dynamo is broken. opening the ...


3

It might help if you gave more details about your dynamo, and/or what your problem is. There are basically three different dynamo wiring systems. Single wire, uses the frame as a return ("earth"), relying on the bearings in your headset being conductive between frame and forks, and clamps or mounting bolts being electrically connected to the frame. Twin ...


3

The roller of the dynamo should run on that ribbed track under the treads. And the axis of rotation of the rotor needs to point very precisely at the axle of the wheel. (I've always checked that with a piece of string!) BTW: The roller doesn't look worn to me. It looks as if it had been machined that way, compare with a new one. And you may also find a ...


3

If the cones were over tightened you would likely feel two distinct notched, one finer one caused by over tightening the bearing cone and a coarser notch caused by the magnet/coil interaction. Because you only described one type of notch I would hazard a guess that it is the magnet/coil interaction, which is normal.


3

The feeling of notches is just the resistance you feel from moving the magnets past the coils in the hub. That's what generates the power. The hub is fine! When you actually ride the bike you won't feel a thing. Well, at least I don't feel anything. Some people have said they feel vibrations from their dynamo hub at lower speeds.


3

I was going to boldly say "no-one has made a rear hub dynamo" but then I did a google search and I'm glad I didn't say that, because I would have been wrong. Shimano make the FH-C810 which despite the FH suggesting "front hub" is actually short for "freehub". In full it's the "Shimano Nexave Di2 FH-C810" (page via searching their site for the short code). ...


3

This is more an electricity problem, incidentally related to bikes, so this is not really a good place for it, however, I'd give it a try. Normally a dinamo is designed to use the electricity in the non-rotating part. To use the electricity inside the rotating wheel yo would need the opposite design. As for it being an unusual situation, it's not probable ...


2

I solved this by attaching a USB connector to the existing light circuit, and power everything with a cheap cellphone power bank. You just need a USB (possibly broken) cable whose "computer" end is working, and a place to hold the power bank. A saddle bag is a perfect place for it. The front basket can also do. Make sure the USB plug doesn't get too much ...


2

Thanks for replies everyone (especially zenbike) After light disassemble i found out what was the actual problem. There was a extra-solder where wires soldered into board that causes short circuit. After that extra was removed light have come to life (YouTube). Busch + Müller are high quality expensive lights, but seems like it is not expensive enough for ...


2

In your update, you note that rather than absolute failure, you have varying light intensity on bumpy roads. This could be for two reasons: This is normal dynamo behavior at low speeds. Basically until you reach a minimum speed (around 10-15km/h), your dynamo power will vary with your speed. Hitting a bump often means a sharp increase or decrease in hub ...


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