36
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 ...
- 121k
33
votes
Accepted
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 ...
- 1,059
26
votes
Accepted
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'...
- 29.1k
17
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) ...
- 57.3k
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 ...
- 81.9k
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 ...
- 7,482
13
votes
Accepted
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 ...
- 81.9k
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 ...
- 29.1k
11
votes
Accepted
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 ...
- 21.8k
11
votes
Accepted
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 ...
- 81.9k
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 ...
- 57.3k
10
votes
Hub dynamo, maybe loose contact; maintenance?
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 ...
- 211
10
votes
Accepted
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, ...
- 21.8k
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 ...
- 81.9k
10
votes
Accepted
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 ...
- 81.9k
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 ...
- 29.7k
8
votes
Rim dish and flange angle problem
Simple idea - turn the wheel over in the truing stand. The low side of the rim should move to the other side.
If the Right-hand side is still low after flipping, your gauge is out and needs ...
- 121k
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),...
8
votes
Accepted
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 ...
- 57.3k
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 ...
- 23.3k
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 ...
- 75.5k
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 ...
- 57.3k
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 ...
- 23.3k
7
votes
Accepted
How to check your dynamo system?
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 ...
- 29.9k
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 ...
- 18k
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 ...
- 29.1k
6
votes
Are there Dynamo powered, rear flashing lights?
Well. I think that you really want this you have to build something youself. Basically you will need a light without a condensator and this circuit. Just add it to the power cable and have fun.
http:/...
- 1,239
6
votes
Accepted
Hub dynamo, maybe loose contact; maintenance?
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 ...
- 29.1k
6
votes
Accepted
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 ...
- 14.4k
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 ...
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