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35 votes

What applications exist for bicycle power, besides propulsion?

Bicycles are simply a method of generating rotational mechanical movement from biological sources. That rotational energy can be used for anything where a motor would be used. The items below have all ...
Criggie's user avatar
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33 votes
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Is there a benefit to turning off dynamo-powered lights?

Yes, there is an efficiency gain by turning the lights off. Cyclingabout made a hub dynamo comparison based on an experiment by skjegg, where power consumption was measured for different dynamos ...
calofr's user avatar
  • 1,114
26 votes
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Consequences of driving a dynamo backwards

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'...
RoboKaren's user avatar
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19 votes
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Dynamo hub lights flickering: should I be concerned?

Shimano hubs and B&M lights should work nicely together. I've used that combination in the past. You need to ride around for a few minutes to charge up the capacitors that power the stand-lights ...
Paul H's user avatar
  • 4,277
18 votes

Output of a Hub Dynamo measured with an Oscilloscope

I have two dynamo hubs here. First a Shimano HB-C050-DR. First I measured this unloaded, and the trace starts as I spin the wheel by hand from a standing start. Note the total (peak-to-peak) ...
Chris H's user avatar
  • 60.8k
16 votes

Can I safely drill a hole from the crown into the steerer in my carbon fork?

When carbon manufacturers and fabricators put holes in things, they're thinking about: Whether disrupting the continuity of the carbon layers in that way will leave it strong enough. Whether there ...
Nathan Knutson's user avatar
15 votes

What applications exist for bicycle power, besides propulsion?

Foot operated sewing machines were very common before electric machines appeared. Unlike hand operated machines they allow using both hands for cloth adjustment, and other energy sources like rotating ...
nightrider's user avatar
  • 7,909
13 votes
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Spokes bow out from the hub flange

Bowing as the outer spokes exit the flange is normal. The angle when the spoke is made is set arbitrarily, and it's the job of the wheelbuilder to cold set it best as possible to match what the ...
Nathan Knutson's user avatar
13 votes
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DIY system for charging battery packs from hub dynamo

Decathlon uses a third party part, that is available for sale if you want to fit it on your bike: Cycle2Charge The category name for this kind of products is "headset cap USB charger" or &...
Rеnаud's user avatar
  • 21.9k
11 votes

Does anyone make a dynamo light buffer battery that will keep it going at full power?

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 ...
RoboKaren's user avatar
  • 29.3k
11 votes
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Flashing light when pushing bike with (constant) low speed

This happens because the power from a hub dynamo (which technically is a magneto, not a true dynamo) is not clean sine-wave AC but consists of short pulses with alternating polarity. At high speeds ...
ojs's user avatar
  • 22.2k
11 votes
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On fitting 700C rims to a dynamo hub rated for up to 20"

Generator hubs for small wheels will output less and produce less drag at a given speed when built to a 700, because they'll be operating at fewer RPMs than expected. AFAIK all the non-sondelux ...
Nathan Knutson's user avatar
11 votes

Is there a benefit to turning off dynamo-powered lights?

In general I leave mine on all day (SP-PD8 and Axa luxx 70) but it does take a little extra pedalling effort. A few Watts is likely to be a couple of percent of your effort, but if you were into ...
Chris H's user avatar
  • 60.8k
10 votes
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Just how bad are bottle dynamos?

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, ...
ojs's user avatar
  • 22.2k
10 votes

Are dynamo hubs specific to particular lights?

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 ...
Nathan Knutson's user avatar
10 votes
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Dynamo light with replaceable cables

Buy the light you want regardless of whether the input wire is integral. As long as some stub or remnant of the original wire is intact, you can make it as long as you want in the future by splicing ...
Nathan Knutson's user avatar
10 votes
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Advice on hub-driven rear lights

Yes, any modern LED generator rear light should be fine. Some brands to look at are Busch + Muller, Spaninga, and Hermanns. Recreating the mounting and wiring cleanly with the new light is another ...
Nathan Knutson's user avatar
9 votes

Can I safely drill a hole from the crown into the steerer in my carbon fork?

I would assume it is not safe to drill into carbon, not at that location. I am not saying that it is not safe, only that I strongly suspect so and that I am not willing to assume otherwise. To state ...
Weiwen Ng's user avatar
  • 34.1k
9 votes

Using a dynamo hub to run ONLY rear lights

Yes, it will work just fine in this day and age of modern LED lighting. A dynamo in its typical operating mode is a constant current device. It provides very high voltage, far higher than 6 volts, if ...
juhist's user avatar
  • 20.2k
8 votes

Just how bad are bottle dynamos?

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),...
cmaster - reinstate monica's user avatar
8 votes
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Can any dynamo hub get the electricity rotating with the spokes?

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 ...
Chris H's user avatar
  • 60.8k
8 votes

Will running an LED designed for batteries on a NEXUS dynamo hub damage the LED?

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 ...
Móż's user avatar
  • 23.6k
8 votes

How does dynamo hub feel at hand?

Remember a dynamo hub has a small electric generator inside of it. What you are feeling when you turn the shaft is the interaction between the magnets and wires in the the generator creating peaks of ...
Argenti Apparatus's user avatar
8 votes

What applications exist for bicycle power, besides propulsion?

Bike-powered smoothie makers are a thing you can rent or buy. They're most often seen at events promoting science/engineering careers to kids, or sustainable travel. Bike-powered electrical ...
Chris H's user avatar
  • 60.8k
7 votes

Do you need to ride gentler with a dynamo hub?

I have never owned the cheap and nasty dyno hubs you're looking at as alternatives, only the SON hub. My experience of the SON is that it has not been necessary to ride gently, and observation of ...
Móż's user avatar
  • 23.6k
7 votes

What applications exist for bicycle power, besides propulsion?

Bicycles are often used for charging mobile devices. A mobile device usually charges with 5 volts (USB) and charging is possible with less than 1 ampere rates -- usually the minimal current unit being ...
juhist's user avatar
  • 20.2k
7 votes

Do hub dynamos with higher power output exist?

Actually a 3 W dynamo is mislabeled. It isn't 3 W. It is 0.5 A. A hub dynamo is mostly a constant current device. The faster it rotates, the higher is the frequency and voltage of the alternating ...
juhist's user avatar
  • 20.2k
6 votes

How to waterproof Shimano dynamo connector?

I use ShoeGoo or Sugru (you can Google both brand names) for waterproofing connectors. The advantage of both is that they are flexible and waterproof, but also relatively easy to remove in the field ...
RoboKaren's user avatar
  • 29.3k
6 votes
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Wheel with Centerlock hub for disc brakes and rim for caliper brakes

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 ...
Grigory Rechistov's user avatar
6 votes

Can I safely drill a hole from the crown into the steerer in my carbon fork?

I faced exactly this question about a year ago. I did all the internet research I could, talked to bike mechanics and emailed fork builders and repairers. The answer that emerged from all this was a ...
dr_strangeloop's user avatar

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