Ok I put a 36cc 4.0 hp chainsaw (2 stroke) on a bicycle, it has a 17 tooth gear on the crank and a 45 tooth gear on the back, The bike weighs just about 30 and Im 180 so the comined weight is 210 lbs , how fast do u think this thing will be able to do ?

What's the diameter of the rear tire? At any rate, I think it'll go like a scalded dog, DOWNHILL! A real dog on the flats, and not at all with any kind of hill. Been a long time since high school power mechanics class. I think you're going to need a very large rear sprocket to make this feasible. It's geared too steep against itself.

Faster than you would ever want to go on a bicycle!!

Trees

Moving this to the Off Topic forum as this is not a Beginner Hotrod or Basic Hotrodding question.

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Hotrodding is much more than just owning a hotrod...It is a state of mind!

wow...what a flash back!

you need a clutch....or a 15 speed de-raelier(sp?)

what we used to build was a 4-5hp motor with about a 3-4" v belt motor pulley and use the (12"?) v belt pulley out of a washing machine on a 20" rear wheel....

for a clutch we'd mount a swivel mount idler pulley hooked up to a hand brake....pull the handle tightens the belt....(LOL, I only weighed about 100 lbs, it would do a burnout...rev it and grab the clutch handle while barely sitting on it)

use another hand brake for the throttle and use a rear wheel with a hub brake...

top speed? 35mph?maybe....which is as fast as you want to go with only a rear hub brake to stop you!!!!

we did it that way so we could keep the regular chain and sprocket to be able to "pedal" on the streets to some safe private property places to have some fun...

eventually the cops did bust us anyway and told us to remove the motor because technically just because it had a motor it is considered by law a "motorized vehicle"....(if a cop in a bad mood pulls you over, you can be looking at $1,000+ in fines!)

hmmmm...grandson is 9, nuts about motors and cars, maybe a good project for us to build together in a couple of years....he lives in a rural area

Do you guys think a normal bicycle chain will hold up ?. And with a 17 gear on the front and a 45 in the back make it torquey ?. Thanks

Anyone know where I can get some plans to build one of these?

Mike