Whats the least amount you can spend?

[uisgdlyast]

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]

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]

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

 

[uisgdlyast]

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]

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]

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.

 

[Dave31]

Welcome to the forum uisgdlyast

 

[seabillco]

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]

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]

last years prices

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!

 

[Jemma Hawtrey]

Re: last years prices

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!

You took the words out of my mouth. With stuff like these bikes the more you pay, generally, the more you get. I ride GEBE and yes it was expensive, but I can be pretty sure that it wont destroy itself or shed bits everywhere..

The most problem i have ever had with it was my fault...

Jemma xx

 

[deacon]

I think I am so happy with my bike because I don't need speed. I am happy to motor along at 15mph as long as I don't to pedal it up the hills around town.

I run the china bike at just a little over that speed even though it will do more.

I don't know the tinkering is part of the fun for me. I guess that is obvious.

 

[comfortableshoes]

In my friction drive I have about $10 in various parts and bolts I've purchased. I got my weed wacker off craigslist for free. I look for towns around me that are "rich" and look for cheap or free stuff there- generally speaking for an inexpensive item (to them) a small issue is a reason to upgrade and buy new so they toss or get rid of the old for cheap, sometimes.

I checked to make sure the weedwacker was turning over freely and pulled the plug to see what kind of shape it was in- pristine, and looked to see that the issue the guy told me was really the issue- in this case a broken gas line. Of course for free- I could have just tossed it if it didn't start.

I also pulled a small kids BMX out of the trash to harvest it's parts- brake lever, cables, and a few other things. That was free but for my time.

If your looking for cheap friction drive is the way to go.

In my other build- a Schwinn OCC Stingray with a 49cc pocketbike engine I've got $250 sunk into it, with at least another $150 going to end up into it. Of course I could have gone the easy route and picked up a HT kit but I want custom. I'm difficult like that. But with a cheap and easy friction drive already running I have plenty of time to space out and get my pricey build right.

Friction drive is the cheapest and easiest build your gonna find.

 

[deacon]

I could not agree more, plus you don't have the chain tensioner going through the back wheel. You don't have the chain jumping off every time you turn around.

I thought I had a sense of accomplishment when I got the China Bike kit running well. That was nothing to the feeling when I rode off on my own designed, personally built bike.

My wife doesn't believe me because she has seen me working on the prototype bikes but the weed whacker friction drive bike is going to be very maintenance free. Double bolt and loctite will pretty much do away with the heavy vibrations that killed my bowlens engine. I bought it new what a waste of money.

I starting my "How to Motorize Your mountain Bike for under A Hundred Bucks" booklet today. I am using the under a hundred for those guys who are afraid to tackle an engine that doesn't run. I'm going to tell them to go to Lowe's or Home Depot for the 70 buck weed whacker there.

For the illustrations, I am picking up a free weedeater in the next town. Broken gas line he says, I think it is probably going to be a sticky carb as well but I have a can of carb cleaner (the miracle repair item) so either way I am pretty confident I can make it go.

For the bike my grand daughter has a mountain bike her father has been trying to get me to take away, so he can get it out of his garage. It has suspension even.

The only downside I see with friction drive is that you cant ride it in the rain. Personally I never rode ANY bike in the rain.

 

[shiloh0]

they ride in the rain alot in england. i personally can attest that it's not a whole lot of fun. even less enjoyable is rain at night on the way to work. i hear everyone say that the friction drive wears the tire out quickly.

 

[deacon]

On the tire wear, that is not my experience but then I don't know for sure. I did just have one put a pretty good sized dent in a new tire. I dropped a running engine on a bike that was blocked so that it couldn't move. That was my fault not the engine's. It does look like it wears them fast because it knocks down the parts that stick up. I will have to let you know about that as time goes on.

I can drop a friction drive tire and change it in pretty short order. If I have to change one once a year I would call that a pretty good maintenance cost per mile. As opposed to a china bike kit that always needed something. I bought three chain tensioners for the china bike at about twenty bucks each. not to mention chain brakers, new chain, rings because I installed it wrong. The china bike was fun and I love it still, but tire wear is a lot more doable for me.