Author Topic: Front dynamo  (Read 4576 times)

ourclarioncall

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Front dynamo
« on: December 01, 2021, 08:47:51 PM »
Just out of curiosity, could you turn your bike upside down and spin the the front wheel with your gags to generate electricity?

Say your camped up for the night and your phone is dead and your battery pack is dead too

And you can’t ride anywhere

Or in an emergency situation

Could you plug a battery pack into the dynamo hub and spin the wheel repetitively to charge the battery pack, which you can then charge your phone from

Or would it be too hard and too long to spin the wheel ?

mickeg

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Re: Front dynamo
« Reply #1 on: December 01, 2021, 09:10:53 PM »
You are unlikely to spin it fast enough to accomplish anything.

Keep in mind your phone probably needs hours to charge.

Dan experimented at one time with wind vanes in his spokes, maybe he can comment.  I think that was on a trailer but could be done on a wheel with the bike upside down.


Danneaux

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Re: Front dynamo
« Reply #2 on: December 01, 2021, 09:49:00 PM »
Quote
Dan experimented at one time with wind vanes in his spokes, maybe he can comment.  I think that was on a trailer but could be done on a wheel with the bike upside down.
I did indeed and as a wind-powered generator, it was very successful.

I used my Nomad -- with its own dynohub and charger -- sitting upright, brake levers locked and propped by a Click-Stand sitting in a tennis ball to prevent it sinking into soft sand.

My Extrawheel trailer was equipped with a SON28 Klassik dynohub, a B&M e-Werk charger and a voltage rectifier I made to power a switchable taillight with standlight function. The trailer was attached to the Nomad, but inverted on its own optional rack so the wheel was free to spin. After a lot of experimentation I developed some detachable wind vanes for the spokes that assumed a cup shape when filled with air, multiplying the wind-driven effect.

I found I could setup the lot at bedtime, plug in my depleted gadgets, and by morning they were full -- provided there was a nighttime desert wind, which nearly always held true. It actually didn't require much wind to spin the wheel. Winds below 9.5kmh, would not spin it. With a gentle push it would start at about 9.5kmh and by 13kmh it was self-starting and self-sustaining. I was not able to check wheel "ground" speed because the trailer was not equipped with a speedometer/computer, but I would guess based on charging that it was spinning about 12-16kmh in equivalent "ground" speed. At any rate, it was "enough" to charge or top off my gadgets by morning (about 8 hours' duration) while I slept. It worked as I had hoped in the desert but of course did not work at all well in the dense forests where I slept on the mountain passes on my way to the desert. A lot depends on conditions and of course, the vane design, load, and so on.

I now don't use the idea so much because of problems with my 2nd generation version of the trailer that revealed themselves in the fullness of time/use and are difficult to overcome despite my further development: The hub quick-releases specified to double as ball-mount hitches are not good as q/rs...the levers go "over-center" and lose clamping force and there is no ready substitute. Also, at the time I got my version (Extrawheel Voyager), the hitch tongue/fork was too narrow to accommodate the drawbolts on rear mudguards. In certain conditions where there was a strong "break" between bike and trailer -- say, coming off a road and through a shallow ditch to continue onward off-road -- the trailer would elevate to a point where the fork hit the bike's mudguard, either folding the 'guard or breaking it outright. I went though two replacement mudguards and even bought a longer Extrawheel fork trying to address the problem and have not yet found a solution. The maker was unresponsive on both the problem/solution as well as whether the newer model trailer forks will work with my older Voyager. Also, the trailer developed a persistent shimmy when loaded with water, the way I had hoped to use it from the start. I found it very sensitive to weight distribution in the panniers mounted to it and it worked okay with lighter loads. I now feel the cargo rating is less than I had hoped for or assumed on purchase.

If you were to invert a bicycle with dynohub and charger, I would caution it needs to be secured well, probably with tent stakes and lines to prevent fallover. You would also risk damage to your saddle and/or grips on rocky surfaces unless you could pad them in some way. For these reasons (and because I have a lot of easily damaged accessories like my GPS atop my handlebars) I have never inverted my bikes to fix a puncture or remove a wheel, preferring instead to lay my bikes on their left side and remove the wheel(s) in that position, which works when with panniers attached. To facilitate the process, I place my hub q/r levers on the right/drivetrain side for easy access.
Related links..

http://thorncyclesforum.co.uk/index.php?topic=4953.0
http://thorncyclesforum.co.uk/index.php?topic=12293.msg90541#msg90541

Best,

Dan.
« Last Edit: December 02, 2021, 01:55:22 AM by Danneaux »

JohnR

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Re: Front dynamo
« Reply #3 on: December 02, 2021, 09:36:08 PM »

ourclarioncall

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Re: Front dynamo
« Reply #4 on: December 07, 2021, 10:36:33 PM »
Danneaux

Wow, thats really cool


energyman

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Re: Front dynamo
« Reply #5 on: December 08, 2021, 09:36:46 AM »
As we are talking of front hub "dynamos".
My wife's mixte bike has a 1.5 watt one which can run just the lights.  I've only found one manufacturer of the specific lights (B & M One Five T Senso Plus).
Has any one come across another light that can be fitted ?
Seasons Greetings