My friends had a weedeater engine powered skate board in high school. Jut had a hand throttle you squeezed to give it gas. You could FLY on that thing. :) Was awesome. Only down side was the really smal fuel cell he mounted. That thing still runs...20 years later :)
We tried making a chainsaw powered bike in shop class and it didnt work at all. You gotta get the gearing right we had a way to big sprocket on the clutch. If you can get the right gearing you'll be good.
I dont think there is that much of a difference. between the two. I think a chansaw would have just a little more power.. But basically they are the same. And i would mount it right infron to the seat post. (like wehre a real dirtbike motor is)
BUT! My dads friend had a bicycle and he put a little wheel insetead of a sproket and mounted it on a slider thing on the front tire. And you would pull a lever to pull it up so its not contact the wheel. And when you wanted to go wout would start the engine, get a moving start and the put the engine down so it made contact with the front tire and the go. i couldent really tell you how fast it was because we couldent get the engine to start but it was a good idea...
Yup and engagible friction drive would be the easiest solution. I'd look at using a scateboard wheel or the like. Fix it to the output shaft and then just devise a method to allow the wheel to be forced against or removed from the front bicycle tire and your good to go.
go for the bike. that motor on a tiny little kids bike would rip. I remember when I was real young maybe 4th grade or so there was a kid in my neighborhood. he would take lawnmower motors and mount them on scooters. he eventually put on on a bike with a twist throttle and everthing. I think. All I remember was cruising around on a scooter with a seat and a lawn mower motor. it was fun. but yeah I was probably more like in 2nd grade now that I think about it
My little brother got an old 2.5hp 2t snowblower for free, it was too small for us to use, so it sat in our barn until he got the idea to mount it on a small bike. He mounted the motor inbetween where your legs would go. He made a shaft to go into the petal housing. I pressed in some old bearings so the shaft would turn, he welded a bicycle sprocket to the shaft, and then a spacer to the outside of the sprocket. He Drilled and tapped the spacer and bolted on a lawnmower pully. Hooked up the old bicycle chain and then bought a belt to hook straight up to the motor. It was geared to high tho. It worked really good, he even rigged up a clutch using a brake cable and a lever to dissengage the belt using an idler pulley, like on a lawn tractor. Just slip the heck out of the clutch and go! It still sits in the barn if I recall. It was a lot of fun and a good project for a 12yr old.