A good friend of mine planted the seed a couple of years ago. Said he saw some cool videos on the Web of three wheelers that had been converted into two wheelers. This fall I came across a guy selling an ATC 200 with a Lifan 200 engine he pulled from a Chinese dirt bike. So I picked up the ATC plus what was left of the dirt bike frame and had myself a winter project!
Here I mocked-up what the finished product should look like (sort of). I tacked it in this position and coasted down some hills to check the handling. Looks like I need to increase the rake cause it turns way too sharp. Looking at BW200 and TR200 specs I need to angle the forks out another 5 degrees and stretch the wheelbase a few inches.
So I've got the engine opened up; needs rings and a lower rocker arm (it's a pushrod engine!). I traced the dirt bike swing arm on a piece of cardboard and then widened to accommodate the fat rear wheel. I also had to locate the drive chain from the engine countershaft so I could begin design of a jackshaft. Looks like I'll use a couple of flange bearings and a 5/8" or 3/4" keyed shaft with a couple of 16 tooth sprockets to do the job. Hoping to start tacking some tubing together this weekend!
Got a prototype swingarm assembled! Next step is to locate the jackshaft to see how everything lines up before I finish welding. The extra bars you see where the engine should go are temporary supports tacked in place to hold the front end together while I experiment with the back.
February 1, 2016
Had to cut-off front end to adjust head angle to 27 degrees and wheelbase of 54". Everything is tacked, time to do some welding!
Jackshaft starting to take shape.
Here's a closer look at the plate behind the flange bearing. Need to do something similar for the inside bearing.
March 11th and I've got a rear sprocket! About 1/16" of runout, not bad.
Final stages here. A few adjustments here and there and the drivetrain should be complete.
April 4, 2016 - Finally got the swing arm finished-up. Reassembled everything with new chains. Going to have to put a guard on that outside sprocket. Starting to sort out the wiring. Previous owner hacked off a lot of connections to lights and things.
Oct 10,2016
Didn't work on the bike much this summer but got back into it recently. Modified the muffler to clear the wide tire, added a kickstand and got the front brakes working. Been out for a couple of drives now. A narrower front tire would do it some good as the 12"er follows every groove and rut in the trails making it a constant fight with the handlebars.
