Someone asked me why I was using belts for the racer's main drive. Kinetic sculptures apparently don't really use belts and pulleys. My main motivation for using belts is gearing down significantly while minimizing weight. Doing that with chains and sprockets would be so much heavier. I also want to reduce the lengths of the tire chains where possible.
The pulleys I sourced from Maedler North America are made from aluminum. The belts are steel-reinforced urethane belts and have trapezoidal teeth. The specs I've read just require that the belt engage 6 teeth on a pulley to get the rated capacity.
There would still be chains from the pedals to the drive shaft and from the drive output to the tires.
We had to do a lot of repairs during the race last year, so in-race maintenance is a top consideration, trumped only by weight. Though it's not bicycle tech, this technology is used in cars and other transmissions. As long as we get properly rated belts, I think it'll work.No special chain tools would be needed to change belts. Just a wrench (maybe a ratcheting one to maximize efficiency).
All the mud gear belts are the same size and can be changed by loosening 2 nuts. The long belt can also be changed by loosening just 2 nuts. It's about the same price as the 4 mud gear belts. Switching the 2 drive belts would be a little more work, since it would involve opening the shifter box. Tightening the belts would be done by adjusting 4 nuts.
However, putting new drive belts on would require opening the shifter "gearbox". I'm working on the shifter design currently, so that process is still a little vague in my mind.
Lastly, I want to use beefier chains (40b) than standard bicycles to connect the drive to the tires, in order to handle the torque being generated in mud mode.
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