View Single Post
Old 09-30-2013, 10:50 PM
jared8783's Avatar
jared8783 jared8783 is offline
Motorized Bicycle Elite Member
Join Date: May 2009
Location: Elkhart, IN
Posts: 216
Default Re: Rugged off road mini bike build thread.

Ok so for anyone who may be reading, I have come up with a minor amount of details and have learned that I need to buy a driven cvt pulley, some sprockets, pillow blocks or even weld in jackshaft mounts before I can figure this all out.

Over the weekend I came up with a very rough mock up of the frame.
Here is the crappy cell phone pic of the mock up. For all practical purposes the only four tubes that exist are the two on top and bottom running parallel from tire to tire, the rest are just holding those in place. The following numbers are very aprox. Ground clearance 9-13", seat height 25-30". and I would like to keep the wheelbase below 43 inches if at all possible.

I plan to surely run two jackshafts. One coming through the driven pulley, and one after that. Then from the second to the tire. This is because this is to be a work horse of a mini bike with really low gearing. I have already done the math for the sprockets and have the gearing numbers for both 11.68 mph top speed and 21mph top speed. I also plan on doing my best to run both gears on top of the cvt. And I will be perfectly satisfied even if i have to come to a complete stop and shut off engine to make a shift. Even If I end up running it as a one speed, I will still run two jackshafts to reduce gearing unless someone has some suggestions.

I think I could use a combination of these, idler sprockets, and two jackshafts as explained earlier, to make it a two speed on top of the cvt. Though I will surely need to come to a complete stop and shut down the motor to stop. But that's perfectly fine with me.

Like I said earlier this will be a purpose built bike. These are similar to the first two speeds on a rokon (and no I don't expect rokon performance). I went to a great off road park for the first time with a friend recently. Camped their all weekend. They allow camping and fishing and all sorts of stuff. They pretty much tell you you can do what ever you want. 750 acre park. I want this bike to get me to camping spots that cars can't reach. I want it to get from point a to b in the park. I want it to pull good logs for fire back to camp.

Most say not to run shocks on a project like this. But I really want to, and I sure will on the front. I have shocks for the rear but may decide against that and use just one of those shocks and suspend the seat or something, who knows.

If anyone has any questions about my gearing or anything else feel free to ask. I'm also open to suggestion of just about any part of it.
a square is a rectangle but a rectangle is not a square

Last edited by BarelyAWake; 01-25-2014 at 12:50 AM. Reason: dead links
Reply With Quote