Inside the gear case what was the differential ? Didn't Dune Cycle just use 3/4 inch axels. On my race trike it was solid axle with double rowed # 40 as with the total weight of the machine and a jack shaft disc brake the chain took a lot of stress. It was a bear to move around on asphalt but running it would just power around. I used to go up on two wheels and turn in circle's just for fun.
Steve
Steve