gas -alternator powered 250watt

Which is probably why torq is so puny down low.

I hate to rain on your parade and people here generally avoid being nay sayers, but there's a good reason "no one has ever done this kind of set-up". It's because it just won't work. There's plenty of good reasons car alternators aren't ever used in bicycle setups. They're super inefficient and you can't possibly spin it fast enough with small gas engines to do anything. You're defeating the purpose at every step you take. But on forums like this, every single day, someone comes up with a brainstorm of "hey, what about a car alternator"!! "Hey, I can charge the batteries while I drive"!!! "Hey, I can put magnets on my bike rims and generate electricity while I drive!!" You cannot possibly charge batteries that power an electric motor that powers the bike while the bike is running under that power. If you add a heavy gas engine to charge those batteries, you just added a ton of weight to rob you of any efficiency that you might have gotten in the first place. You seem to be thinking you're coming up with a new invention no one ever thought of. You're not by a long shot. And you can't silence a weedeater motor. They are the loudest of all gas engines. If you DID manage to silence one or another small gas engine, it would mean you blocked most of the air coming out of the exhaust and you'd lose most of your power if it would even run at all. You obviously have money to burn to find out eventually what I say is true, but you'd be much better off to just use a traditional electric bike motor and traditional batteries and be done with it and accept that your range will suck because of what we have available to us. There are plenty of choices of bike motors available to you. There are few choices on batteries. All this stuff about a heavy gas engine turning a car alternator on a bicycle is hogwash and you'll find this out in the end. But on the positive side, you'll have another contraption we can add to the Rube Goldberg archives. And I have no idea what you meant when you topped it all off with the "Austrellia" comment. What does this have to do with motorized bikes in Australia?

There's a couple of lil differences that sets professor's scheme apart from the dreaded perpetual motion babble.

1: As far as I understand it he's not lookin' for "free" power, he's goin' for more the hybrid setup.

2: He's actually experimenting and building stuff - not just "armchair engineering".

Now - while I'm not sayin' it'll work, but I for one am glad he's trying. One BIG thing he did prove beyond a doubt is that a weed whacker engine doesn't have the cojones to push an alternator!

That quote alone is worth it's weight in gold. Regardless of what is thought of the project itself - I have massive respect for those that'll break out the tools and try! Who knows? He just might surprise us all!

Well Popcorn, I already did silence the wacker motor with a muffler I made. It is on the other forum. Went from 90.5 db to around 85. Large diameter tubes = no loss in power.
An alternative to the alternator would be another DC motor, however, that would mean having a clutch on the engine to cut drive to the actual drive motor when you want zero forward movement.

I do not know how locomotives work in detail, but they have a diesel driving a generator which drives the wheels. This is the concept I am after.

I do agree that alternators are not real efficient. They are real durable and inexpensive though.

By the way, I hadn't mentioned, that the only battery on board will be a small 12 volt one to energize the field, switched on with throttle opening. I want to tap off the big power to put charge into the battery while running with some kind of regulator and a diode.
I doubt I will need anywhere near the full 2.5 hp the engine is rated at to run it.

Thank you, Barely awake, for your comment.

Those big diesel-electrics are far more common than some may know: Diesel-electric transmission - Wikipedia, the free encyclopedia

While a liveaboard I looked into a scale version for my application, the numbers work out great for a slippery displacement hull and a battery bank - the concept goes way back: Elco History They even had fuel gennys onboard with similar thoughts in mind - of course they were steam or naphtha lol

I see yer bike as just yet another scale down. I dunno if it'll work out - the math gets troublesome the smaller a vehicle it is, land vehicles also have variable demand considerations that boats do not (hills and traffic driving).

Yet the tech is proven for what you wanna do - those WWII subs wouldn't have got very far w/o it lol

hey professor ive got an old craftsman 500 watt genset in the garage that i tried to get going. but the carb was so jacked up there was no getting it going. and and there are no more parts available.the genset works and ive still got the power panel . it is belt driven and the motor is only a 1 hp. Do you think that might work ? it does have a 12v out put on the power panel

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The problem is we want 24 volts to the drive motor (or maybe more since some scooters go higher) I guess if you had a 500 watt drive motor and you run it on 12 volts, you will have 250 watts of output. You would be pulling a bit over 22 amps to do it. That is more than house outlets I think

I have sucessfully put different carbs on small engines- especially the Techumseh. I like the carbs with the primer bulb. Main jet is on the side of the bottom plug that holds the bowl on- they get full of junk and stop flowing. Thus, we find free mowers often. A guitar wire or welding tip cleaner and some compressed air fixes them. REAL simple carb.

sorry didnt read the 24 volt thing!

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