Generator using my motorcycle?

What about using my motorcycle as a generator to charge a battery bank by placing the rear wheel on a spindle that turns a generator while the bike idles? The spindle can be geared to run any speed using different size sprockets. Obviously there are more efficient generators, but I already have the cycle, and I won't be riding it in winter. One less engine needing maintainence.

Motorcycles are horrible gas pigs. Most are far less efficient than other gasoline powered vehicles.

Most motorcycle engines are air cooled, even the more modern engines with a liquid cooling system are cooled by air moving over a radiator, so extended running without moving is probably not recommended. My air cooled '81 honda cb650 absolutely suffered if I got stuck in traffic and had to idle. Some have fans mounted to the rad, but even still I"d be really hesitant to run stationary for extended periods. If you do decide to try this, your motorcycle already has an alternator that is setup to charge the 12V lead-acid battery which is used to run the starter, lights, and provide spark for the plugs, so in effect you already have a smallish 12V DC charging system that you can use with zero rigging, add an inverter and you might be able to have some limited 120V AC power... I'm not sure what the specs are on a motorcycle alternator off hand. I'd opt for buying an inexpensive gas generator if I were in the same situation.

the alternator on a motor cycle is way to SMALL to be of any use to anything. It basically just runs the head light and the ignition and that's about it. You're looking at a LOT of cluging something together to get very little out of it. You are by FAR better having a 1 deep cycle battery bank and a $89 harbor freight 2 cycle generator. Youi'll spend less on both than you will trying to am string some pulley and gear system from some motorcycle rear tire to an alternator.

Steve

i thought the OP was asking about hooking a gen-set up to a motorcycle and using the rear sprocket as the driver.

i have thought about this as well.
i dont see why it couldnt be part of a power recovery strategy. if you have or could get a motorcycle that has been wrecked, it would be easy to mount a genset and connect the 2 via a chain.
i like the idea because a lot of the smaller generators arent meant to run 24/7. most seem to have 2-3hr cycle times, whereas a motorcycle could idle/1st gear for much longer (assuming you can keep it cool)

Motorcycles are gas pigs? I get 50mpg minimum at an average of 75 mph. There is a reason third world countrys are filled with bikes they are cheap, easy to maintain, and get great gas mileage. Unless you are reffering to a boss hoss( v8 powered bike) or some of the ludicrous bikes produced in the last decade with motors over 2000cc (110ci). My bike is more efficient than those god awful prius' and you don't have all the toxic materials from making the batteries,wiring, and plastic bodywork

Okay, allow me to re-literate.

This would be an EMERGENCY back-up generator, not full time. My cycle is water cooled, most back-up generators are air cooled, so I don't think overheating is an issue when running at idle, especially during Winter when this is most likely to be used.

This would NOT be hooked up to an alternator, but to an electric motor, and only if a back-up generator was needed. The cycle could be rolled onto a roller assembly that turns the generator flywheel, and rolled off again if needed for transportation. If you've seen a dynometer, then you know what I'm thinking about.

Seems to be a lot of naysayers here. BTW, If you think going to the store and buying another 2 stroke engine is the answer, then you might be on the wrong forum.

I recommend that you match the power performance of the bike (idle torque at the tire) to the torque required of the generator. This might be quite small for a inline 4 and higher for a V twin. If the starting torque of the generator exceeds your torque at idle for the bike you will constantly stall it. If you can't find a generator with a small starting torque you might be able to compensate by putting a very large cog on the generator drive shaft.

Then I recommend that you have a very strong support for the generator (made of steel) and not attached to the frame of the bike (typically aluminum).

Good luck with the project!

That would work fine if you charge to the batteries and then utilize the DC power or invert it. The problems that I can foresee are related to AC frequency control, but stay away from AC generation and you should be fine.

josh mccormick wrote:Motorcycles are gas pigs? I get 50mpg minimum at an average of 75 mph. There is a reason third world countrys are filled with bikes they are cheap, easy to maintain, and get great gas mileage. Unless you are reffering to a boss hoss( v8 powered bike) or some of the ludicrous bikes produced in the last decade with motors over 2000cc (110ci). My bike is more efficient than those god awful prius' and you don't have all the toxic materials from making the batteries,wiring, and plastic bodywork

I believe Dale was referring to motorcycle engines being less efficient than car engines in terms of work done per amount of gasoline used. Just making up numbers, but we could assume that it will take twice as much gasoline to accelerate a Prius from 0 to 60 MPH as compared to a motorcycle. While the motorcycle used half as much gas, the Prius engine was twice as efficient because the Prius weighs four times as much as the motorcycle. Since the OP's idea is to use a stationary vehicle, we are left with a scenario where the weight of the vehicle does not matter.