Stanton has the right idea and it looks good, but this gear box weighs about 10 lbs and is priced about $175, very expensive.
18.75 to 1 Outside Drive Reduction Staton Gearbox for most 76 mm Clutched Engines.
www.staton-inc.com
In contrast, the double right-sided drive I developed uses a $25 5:1 goped gearbox and weighs about 3 lbs.
I'd like to see a less expensive solution using a cheap $25 3:1 gearbox mated to a 9 or 10 drive gear and a
56T wheel sprocket. Here's the gearbox:
https://www.monsterscooterparts.com...cc-engine-mini-atv-dirt-bike-pocket-bike.html
This solution would mount to the left side of the bike and would take any engine with a 76mm clutch, like the
Honda GX50, GX35, Robin 35, Lifan 35. The motor mount is the challenge to invent and develop. I'd like to see
2speed put his invented talents on this approach rather than reinventing front and rear wheel friction drives that have been
on the market since Egypt used straw reinforced mud bricks. Sorry to be so blunt but I believe serious inventors
should not reinvent old ideas.
Check this guy out:
Put this on the market, and you may have to quit your day job.