Since early this morning I've been searching for some answers to the questions asked by others and in the process I've recalled some answers that I was already aware of, but had not repurposed recently. So here goes my thoughts in general and then in specific as well.
In general as relates to the go cart style 3 position gear box. They feature forward, neutral & reverse. run 35 or 40 chain, cost $120.or so, select either a 5/8" or 3/4" bore to fit your motor & are 3/16" keyed & can handle up to 13 hp when coupled with the 30 series cvt. The gear box is a small package. Offers wide application universality with small 4 stroke engines of 3 hp up. Straight taper output shaft ready, can't accept a tapered output. These can also support the 3D clutch setup for single speed with reverse builds. Reverse speed internal gear reduction is double the forward reduction, and 2,800 rpm at the shaft. It is an oil filled lube system.
This box can also be easily coupled with an electric motor and standard controller to reverse the power output of the dc motor without controller modifications and provide the appropriate gear reduction, in the case, for neutral & reverse. Trucks, trikes, Velos and sidecars are all likely candidates for consideration of the gear box use. The heavier vehicles & those with greater turning radius are most likely applications.
My specific application would be to use the reverse gearbox on my sidecar build. To not only reverse the car wheel but also propel the rig for emergency situations and only at very modest speed. Run out of gas a few miles from help...no problem. Ever had a bike die at a stop light? It's dangerous as is being stopped on any highly traveled motorway. I feel compelled use this solution to power my sidecar rather than alter the controller: the reason being the appropriate gear reduction produced in the gearbox and the ability to run a smaller final drive sprocket as a result. I want to crawl in reverse and maintain a reliable 10 mph going forward and all this with the relatively small 48 volt 1000 watt motor.
The total cost is still way under that of a bike motor swap. It adds power redundancy for emergencies and I'll still have the added ballast for car balance. I'm having a hard time rejecting this as my best alternative for adding reverse to my sidecar and it's electric!
Rick C.