gas/electric bicycle?

[Thomson85]

Ok so I was going to buy one of those 2-stroke china 50cc engines, but I want something I know that will be dependable. So I am going to pick myself up a weed wacker/chainsaw/or leaf blower engine and using it instead. But I also had this idea, and am not sure if anyone else has thought about this.

Taking a small generator... I found one on craigslist for $60, and have it power an electric motor that would run the bike. I think this would be interesting as the gas generator would practically be at idle (gas saver) and everyone knows the acceleration benefits of having an electric engine (they're FAST).

Would this be practical? I think it's kinda like having the power of an electric motor with the benifits of not being dependent on batteries or charging. The fuel consumption should remain minimal as the load of an appropriate motor shouldnt drain the gas generator and should produce fast acceleration from a dead stop. Not to mention as far as "red-lining" an electric motor is practical not to blow the motor apposed to a gas engine!

Any comments?

Don't get me wrong this will most likely be a project of the future for me, for now I will just use a weed wacker motor.

 

[Member 5549]

Sounds cool but you might need 2 batterys, one to charge and one too run on.
and have a selector switch to switch from one to another.
also you will need a charger to run between the genarator and batt..
not sure but the weight might become a prob.
thats going to require a lot of real estate to mount all that stuff.
but I was reading about the Chevy Volt electric car, it will have a small engine too only charge not propell the car.
Sounds like one heck of a project.. but you might be on too somthing !!!

 

[srdavo]

seems like someone here has attemped to generate power for their electric bike...?
anyone remember? link, please.....

here's a fun thread about homebuilt motored bikes...enjoy
http://www.motoredbikes.com/showthread.php?t=4770

welcome to MBc.

 

[Thomson85]

2 batteries? No I dont think so... Im not speaking of a rechargable electric motor, I mean one you would plug into a regular house outlet.

So basically on a rear mounted rack you would first have the gas generator (not big at all with only 1 outlet... ill look for a pic), then after that you would have the electric motor from either a weed eater, leaf/snow blower (whatever size you desire).

There would be no need for batteries, just plug the engine into the generator, start the generator and the electric engine will run....

Or am I missing something? The generator will provide enough electricity to power the electric motor, meaning it should be able to do so at idle or just above idle, meaning major savings in gas....

convenience of a gas engine (no recharging or distance restrictions) with the speed of an electric motor (Fast with LOTS of torque)

 

[Thomson85]

Here's a rough concept I made on paint, basically you just plug the motor cord into the gas generator just as if you were going to use any electric appliance (non-battery operated)

http://img20.imageshack.us/img20/891/conceptct2.jpg

 

[thescooterguy]

what powers the generator ? wouldn't it be best to have gas motor to run bike and charge battery for electric drive then switch back and forth like the hybrid car ? i have toyed with this idea but its just the wiring that gets me . i would use a gas motor with an e start to send power to batteries .then a hub type eletric motor on front or back wheel .

 

[Thomson85]

what powers the generator ? wouldn't it be best to have gas motor to run bike and charge battery for electric drive then switch back and forth like the hybrid car ? i have toyed with this idea but its just the wiring that gets me . i would use a gas motor with an e start to send power to batteries .then a hub type electric motor on front or back wheel .

Read above it's a gasoline generator... you know the kind people buy for natural disasters or construction companies... So it would be like this.... I have said it 2 times already!


It's a 4-stroke gasoline engine generator, that powers the electric motor! So the electric motor is PLUGGED into the gasoline engine generator!

Gasoline engine generator > Provides constant power to electric motor. Using less gas to produce electricity to the motor. No charging, quick throttle response.

Understand?

 

[thescooterguy]

got it now , came in late , sounds good

 

[SimpleSimon]

There has been substantial discussion of the idea in several threads here, and at least two members have built gas/electric hybrid drive vehicles - a bike and a delta trike. Gas powered generators (even small ones of 1 KW or so) have substantial weights and physical footprints. The smallest I have seen was 36 lbs and is about 14" x 20" x 16" high. Most such built commercially are designed to deliver AC, with a small capability to provide DC (usually around 6-10 amps at 12 volts), so you'd likely have some electrical work to do to get substantial amounts of DC power.

Acceleration using an electrical motor as the prime mover of the bike requires fairly high draws of power, which represents a big demand surge. In the absence of a battery to serve as a reserve current source to meet peak demands, you'd likely blow the surge protector on your generator repeatedly.

Don't get me wrong - I'm no electrical engineer, and mayhap you can make your idea work. Good luck, and keep us posted on your efforts.

 

[Thomson85]

I wouldnt need to use DC power as I can just use a standard 120v electric motor... like a electric weed eater (that you plug into you house 120V). I wouldn't imagine it being a little past idle to power something such as a weed wacker motor (electric).

Yes, weight seems like it could be an issue, and that's why distributing it through out the bike would be essential and preferable centered. That's why this re-vised drawing I would move the electric motor to where a lot of people place their 2-stroke engines



http://img155.imageshack.us/img155/465/concept2yx3.jpg