Reverse thoughts...

[XLerate]

Hi all!

Reverse thoughts, maybe the same as bassackwards. Don't know if this has been covered before, haven't found it here yet myself. Regarding reverse on some builds, it may be quite easy:

You can use a 12V starter motor with the right sprocket to give reverse. If starter motor is turning same direction as engine, then engaging starter motor on opposite side of chain from primary drive sprocket contact side runs chain in reverse direction. That's of course the 'outside' of chain.

A simple swinging bracket for starter motor can be fabbed up with a spring assist to hold motor normally disengaged, out of contact with chain. You shift bike in neutral, swing starter motor down to engage sprocket to chain, hit the heavy duty 50 amp switch & bike reverses.

Also possible to use a momentary contact bayonet switch [push-button or micro-switch] at least 50 amps so that simply swinging starter motor down to contact chain also energizes motor switch at the same time. Swinging assembly would need a heavy enough spring to disengage, so that a rough road would not cause contact.

A little more challenging with a toothed belt drive. There a swinging jackshaft driven by starter motor, with 2nd pulley to engage inside of drive belt, could accomplish the same. The 2nd pulley would need to be on toothed side so a reverse direction motor, or swapping motor end for end, would give reverse. This would apply to vee belt drives also.

The main drawback to this is very limited contact of drive teeth from starter motor, in that chain or belt doesn't wrap around sprocket. At least with a chain drive the normal slack would somewhat improve tooth contact.

This could give a simple, clean & compact reverse drive without a whole lot of grief on the engineering.
XL

[coachgeo]

course there is also rev. gear boxes

Not sure which needs more room... stuffing in another small gearbox into the mix or stuffing in a starter motor, swing arm etc.

[coachgeo]

Dont some of the add on rev. units friction drive? Simlar to your idea but instead swing arm presses a small rubber wheel onto the rear tire. It to powered by a starter motor?