Chainsaw Build

[ZMX]

For my first build I just bought a Craftsman 18 inch chainsaw from my local flea market. Its mate will be an aluminum Mongoose mountain bike with 26 inch rims.

I'd like to run it as direct chain drive. I understand that they spin >8000rpm, and that the reduction to <600rpm will be a difficulty to overcome. Also, I know the engine must stay under 3000rpm if I don't want the clutch to burn out. I haven't settled 100% on whether or not to mount it to the handlebars and attach it to the front wheel or to buy a bike rack and stick it on the back.

I have, however, come up with a design that I believe will work in reducing the speed while keeping fabrication to a minimum. Tell me what you think.

P.S. Blah, wrong section. Feel free to flame me/move the thread.

 

[SirJakesus]

I would do it on the rear wheel and get a freewheeling left side hub so you can pedal or coast down hills with zero drag.
I've seen a few front wheel drive bikes but I think they're better suited if you're going to be carrying large loads on the rear of the bike.

 

[eljefino]

I bet the chain goes much slower than you expect. Maybe paint a couple links white and shoot a video to see how many times a second that link goes by.

This will tell you your RPM at the saw sprocket, which will be a starting point.

 

[Alaskavan]

It looks interesting. The saw bar isn't very thick. You will have to pay particular attention to how the reduction gears are attached to make sure the pressure on the bearings is even.