The never attemted..(plz look)

weekend-fun · #1 (**permalink**) 07-19-2009, 07:35 PM

Hey,
I wondering if any one has ever attemted to make a generator on the bicycle so when the ba and or front tires spin, it generats electricity to a eletric engine. My rough idea is to put magnets on the tire and frame so that they pass by each other, than the wires go up to the motor and give it energy?
Hows that sound and do you have a better idea?

Large Filipino · #2 (**permalink**) 07-19-2009, 09:06 PM

You'll need a battery in between. If you can generate more power than what you use then you made something that people have been trying to make for generations.
At best you'll extend normal battery range which may still not be a bad idea.
When it's parked like when you go to work a solar panel may give it a good trickle charging.
Maybe down the road with technology 150 mile range is possible.
It may already be possible.

Scotchmo · #3 (**permalink**) 07-19-2009, 09:19 PM

If you have an electric motor hooked up to drive the wheel, than you already have a generator. A motor and a generator are basically the same thing. There is no energy gain by running a generator off a motor and then hooking the wires together. Because of inefficiency, you actually lose energy.

Think about this; the simplest mechanical equivalent of that concept has no efficiency losses but still buys you nothing. You put a bigger wheel on the back of your bike so it is always pointed downhill. The difference between the two is that it is more obvious why the mechanical implementation does not work. Neither concept works for the same reasons.

weekend-fun · #4 (**permalink**) 07-20-2009, 11:15 AM

so, i would actully LOSE power by doing this??

Finfan · #5 (**permalink**) 07-20-2009, 12:58 PM

You can't get more out than you put in. If you could all of our energy problems would be solved! If you want more info wiki "Perpetual Motion" and "Laws of Thermodynamics".

weekend-fun · #6 (**permalink**) 07-20-2009, 12:58 PM

i thought i could run a wire from the magnets, attach it to the plus side of the battery and then run a wire from the - side to the motor. Would that work? i think so.
all i want to do is increase the mileage.

deacon · #7 (**permalink**) 07-20-2009, 01:01 PM

sounds like it but you have to remember that when coasting you wont be using power you will be making it. It's the recumbent braking theory. When you kill your drive motor you will still be making current in the generator. Probably not enough to power a bike but enough to extend the range a bit.

The next generation of power bikes may well have something like that as part of the system. For instance on my hub bike I am going to pull a battery trailer so that the bike will handle better not be so top heavy. What if I turned the trailer into a generator by hooking a motor/generator with a diode to one of the wheels. It would turn independently. When the bike pulls the trailer, but would also turn when the bike is coasting down the hill. It would even turn full speed even when the hub motor is at a lesser speed. So in theory I could maybe get a 30% return of energy adding that same amount to the range of the bike.

It's worth a thought. The real problem is a 350 watt motor would have to turn at 2600 rpms to generate 360 watts per minute or whatever the rating is. It most likely would not do that so the return would be much less.

I build my power trailer from scooter tires. I have a scooter tire with a 80 tooth sprocket. The motors have 11 tooth sprockets. So it would probably be a pretty good generator power source. I'll have to give that a try one day...