I'm upgrading to full suspension Ebikes for the wife and me. See http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=17242&p=251772#p251772
How about this new plan for doing an RC bike on the Prophet:
Make a 1 stage 15:1 or 20:1 reduction using a very long timing belt.
1. Mount a 1 or 1.5" fine pitch toothed pulley on a Astro 3220
2. Use a 20" bike rim as a large smooth pulley. Mount this to spokes of rear wheel.
3. Somehow find a matching very long fine pitch toothed belt.
Plan is to run this with 36 to 48V 15Ah A123 pack with a 100A+ controller. Using a 3 turn 3220 with 20:1 reduction speed (under full load) at 48V should be about 60km/h with 10,000rpm on motor. This is for offroading.
To go faster I can just swap in a larger front pulley.
A conclusion from the thread http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=17401&start=15#p254804
was that it is good to build in some slip/clutching into the drive train to reduce stress on touchdowns or other sudden acceleration/de-acceleration during aggressive riding.
Here I was thinking to set the belt tension just tight enough so it doesn't slip under full motor acceleration, but it if forced by a sudden jerks / large forces on the rear wheel the belt can slip instead of back driving the motor. With a toothed front pulley the slip will happen on the very large rear pulley/rim. That should be large enough to dissipate any friction heat.
There are plenty of BMX 20" rims I could try for the rear pulley. Just have to find one with a reasonably flat bottom.
Any tips on where to find the long belt and matching front pulley? I'm hoping for a lighteweight belt with a small tooth pitch. Maybe 13mm or so wide belt, and with lengths over 2m available.