Whats the least amount you can spend?

uisgdlyast · #1 (**permalink**) 07-27-2008, 06:10 PM

I've been interested in doing this for awhile and have read a lot of the posts here (I still need a lot of reading to do though).

Anyways, before I really go and consider this I was wondering what is the least amount of money I can spend on setting up a motorized bike if I already have the bicycle? (under 200$? can I do it for around 100$?)
My plan was to just buy a used motor (from a weed wacker or something) and set it up on the bike. I weigh less than 150lb so I don't need anything too strong, and it will be short city driving for the most part.

Also, it looks like a lot of people use mountain bikes for the set-up (or those coaster ones i think). Is it possible to make a motorized BMX bike? I assume there is not a lot of space for the engine unless you mounted it differently, but I'm young and figure a motorized BMX would be cool and you can get some really light frames.

deacon · #2 (**permalink**) 07-27-2008, 06:31 PM

If you go friction drive you an put it on anything at all. The amount depends solely on what you plan to do. You should be able to set up a friction drive on your bike with a used motor for under a hundred bucks easy. Remember used motors might need some cleaning ect.

Try to buy in yard sales or flea markets so you can hear it run.

**Bikeguy Joe** · #3 (**permalink**) 07-27-2008, 07:35 PM

Used yard sale weed wacker+cheap bike= motorized bike for under a hundred.

uisgdlyast · #4 (**permalink**) 07-27-2008, 07:56 PM

Cool, yup I've been looking on craigslist and found some weed eaters for under 50, I assume I'll need some more supplies though.

Anything to look for when I'm getting the weedwacker/eater? I still need to do a lot more reading but I'm pretty new to motor terminology so I dont know the horsepower or cc i should be looking for.

**Ilikeabikea** · #5 (**permalink**) 07-27-2008, 08:11 PM

Welcome to the forum. Looks like Deacon and Joe are taking care of you. They are great motorized bicycle builders. Glad you joined us................

deacon · #6 (**permalink**) 07-27-2008, 09:11 PM

Make sure the engine runs. Do not take their word for it make them start it. How do you want to use it, how is the terrain there.

Generally speaking the more cc the more power you are going to have. For ease of build and best cost efficiency go with friction drive I think.

You can get some help with even the smaller engines but I just finished my first build where I got the 31cc engine to work. It does almost as good as the China bike i have.

I also have a 25cc I'm going to rig to see what kind of pull it has with the same mount and drive wheel. I will have a comparison soon. Couple of days no more I would think.

**fairracing31** · #7 (**permalink**) 07-28-2008, 12:13 AM

Welcome to the forum uisgdlyast

seabillco · #8 (**permalink**) 07-28-2008, 06:05 PM

Hi,
I just built a friction drive bike for $5.
I used a 31cc Ryobi I took from a tiller I had and scraps of plywood, steel and aluminum.
The $5 was for a BMX peg I used as a drive roller.
For details, here's a link to my personal blog that includes a video of me driving the bike:

steverg.blogspot.com: Motorized Bicycle - DIY

I have since bought 5 used engines on eBay for about $25 each and all of them run fine. The 2 strokes are very simple.
I've also motorized a recumbent with a 4 stroke and it's my favorite ride.

Good luck!
Steve G.
Grants Pass, Oregon

deacon · #9 (**permalink**) 07-28-2008, 06:46 PM

Your frame is basically the same as mine I think. I use a scissor type hinge that is made from a couple of mending strips to allow the motor to swing up and down. I use a lever from the front to lift it. And spring to hold it in place. So far it seems to work fine.

srdavo · #10 (**permalink**) 07-28-2008, 06:49 PM

used homelite chainsaw....$30
freebie bicycle
scrap metal from work........free
6 hours labor=fun

motoring down the road the same day....priceless!!

And a lifetime of tinkering....
I dint say it was motoring well.

looks like I got what I paid for....

Seriously...I don't mean to discourage.

Homebuilts Rock!