Maybe the last chapter in the C&E drive roller. My wife was throwing away a 1" thick oak cutting board. Perfect material to experiment with. I had used oak before but the torque the Lifans produce would break the roller loose under high load hill climbing. Cut out a 2.1" to try. Produced a really nice smooth driving roller, but still would slip on steep hills. So I began to increase down pressure, way higher than the rubber rollers required. finally I hit a point that would hold the engines torque. It requires a LOT of down force, right to the point that the lift clutch is getting pretty hard to pull, but still useable in frequent clutching situations like traffic. So after running the 2.1 for quite a few miles, a hundred or more, the conclusion is the Easy Oak Roller is the way to go. At this point shows about zero wear, yet it sees a lot of dirt and gravel riding. I cut out a whole range of rollers, that are easy to fit in the bikes bag and change out in less than a minute. They run from 1.6 to 2.4 with the every day rollers being either 1.9 or 2.1. These give a range of speed from 19 to 28mph on the governed Mongoose to 26 to 39 mph on the ungoverned Schwinn. With the 1.6 the bike would probably climb the face of Mt. Rushmore it has so much pull ability. On lesser powerful FDs the downforce could be less I am sure. The thinner roller in the pics is a fir roller cut from a 2x4. They make a good proof of concept roller, and never failed with 2.5hp. Would probably be just fine on a lower HP engine with narrower tires.
