Just as the title says, I need to find a cheap motor for a project a friend of mine and I are working on.

He’s an electrician, I’m a welder.

So we have the knowledge, but we are both cheap and want to try our hand at this ebike thing. So here is a basic idea of what we are wanting to do.

3 wheeled so we can carry parts, tools, and such back and forth when we need them. The 3 wheeled bike will make it easier for us to hide the motor and battery and make it a more stable. See we want it to be somewhat covert as far as people knowing it is a powered bike.

We live 3.1 miles each way and could travel most of that on a atv trail, but would have to travel a few hundred yards on the street. Speed is not that important but I would like to get 30 MPH out of it on level ground. That would give us enough balls to make it up his driveway, I hope.

So who has someplace that has cheap motors, or any ideas on finding a used motor?

I don’t want a hub style motor. And as this is a low budget project we would like to keep the whole thing under 100 bucks. We have bikes available that we can turn into a 3 wheeler.

Any help would be appreciated thanks ahead of time.

I don't know what you mean by cheap but Cyclone taiwan has motors for ebikes up to 1000 watts. As far as stealth goes, high speed motors always make some whine. You'll need to step the speed down about 9.5 to one. If you put it in the chain line, it will make it up any hill that you could climb. 30 mph on a trike is dangerous unless you can lean the wheels to corner.

the cyclone motors are somewhat expensive. but then, so are the alternatives. hub motors are generally the cheapest thing you can get, especially if you get ones with imperfections (http://www.electricrider.com/yardsale.htm).

On e-bay is an inexpensive motor (http://search.ebay.com/search/search.dll?query=480kv+swang) that should be adaptable to bike use at 1000 watts if you gear it down (somewhere around 14 to 1) and run it at 12 volts. (apparently it can be run at anything between 6 volts and 40 volts, but for a bike you won't want to go above 12V and 1000W unless you gear down more). One of the ways to gear down 14 to 1 is to go to this site (https://sdp-si.com/eStore/) and buy a 9 tooth "#25" sprocket and a 125 tooth #25 sprocket, and then buy a #25 chain (but not from that site, if it's cheapness you're after).

You'd have to make mounting brackets and stuff to get the motor on the bike, and the sprockets attached where they need to be. If you have to pay anyone to make the mounting bracket stuff (in a machine shop, say) it'll cost you quite a bit.

you tube is a good place to look for alternative ideas. electric lawn mower and treadmill motors have been used along with 12Vdc to 120Vac inverters to power them.

you're not gonna find ready-made bicycle motor stuff for that price - except look on craigslist or local sales for somebody with an older eBike that's dead.

Thanksfor those sites. that’s a place to start. Motors are used everywhere, 12 volt motors are used in even more places. I was hoping to find some one who knew of a 12 v motor used for another purpose that we could pick up cheap.
The 30 MPH would be for straight away only and the ability to go up hills with a very heavy load. See if I need to go get my small 220 mig welder we are talking about some serious weight with the welder, tank and assorted tools. I would bet it would be around 200 lbs just for the tools.
I read somewhere that a robot maker uses auto starter motors for his robots. Not sure about life span or speed but something like that.
As I said I am a welder/fabricator, so making the mounting brackets is not a problem. I also have a farmer friend who at times has turned shafts for me as a favor. So any real machining will not be a problem, or expensive.
Thanks again.

One of the first ebikes I ever heard of was home-made and powered by an electric drill motor. Electric drills are cheap and easy to find, and probably an OK choice for your project.

You could set it up as friction drive if you like - where a small wheel sits on the bike tire and turns to push you forward. (or chain or belt drive) friction drive doesn't work well on wet tires.

Friction drive is no good as it can be seen. Electric drill I would think doesn’t have the torque for the hills. I wouldn’t think.
As I said I can make just about anything needed as far as gearboxes and mounts.
Starter motors are easy, cheap, as in free to me. I have a half dozen old cars out back so they would be free.
I just wonder how long something like that would last.



http://robots.freehostia.com/Motors/Starters/Starters.html

Starter motors are easy, cheap, as in free to me. I have a half dozen old cars out back so they would be free. I just wonder how long something like that would last.

Not long as most starters are designed for short duty cycle. Least of which most use bushings which will be toast in under a mile, I suspect. But, hey - you got the means and time, give it a try and share the results?

Some folks have found promise in rewinding 3 phase automobile alternators into some type of electric motor and gearing it to the bicycle crank. That's where you will have most luck using smaller motors - through the bicycle gearing system.

starter motors provide crazy torque....for a few seconds. If all you need is a quick burst to get you up a street, it might be the way to go. Just remember you will need a battery with high current flow capability. So, assuming one of those cars has a starter, battery and starter solenoid, you just might be in business. Ofcourse if you require more than 15-20 second runs, you might be S.O.L.