two speed scooter

[dcb]

I just always wanted to experiment with retro-direct. Seems to work pretty well so far.


It should say each sprocket has its own freewheel, not flywheel

[dcb]

you do have to keep the chain tight though, or it likes to jump off. maybe a spring loaded idler is better.

here is how I got two freewheel hubs on there, you might want to grind off a bit of the parts that might rub on the freewheels, mine have self machined pretty well though.

basically figure out how much to remove to center the hubs on the threads, then carefully removed it by giving the wheel a good spin and grabbing the angle grinder.



Also, you want the sprockets to be as close as possible, ie the big one is on the outside of the freewheel and the little one is on the inside, and they both have tapered countersunk bolts holding them in.

[dcb]

one more pic, make absolutely sure you have the direction of rotation and the sprocket sides right before you spin on the freewheels, they are a pita to get off in a non-destructive manner. I had to chamfer the bolt holes a bit more too.

I guess what I find fascinating about this exercise is that what seems missing from many non-hipower EV's is a couple gears, and this looks like about the least intimidating way to accomplish that. It does pull my butt up a hill no problem, and I can almost wind it up in top gear, so I think I got lucky with the teeth counts. Better battery is next, maybe some pedals and call it a bike.



You can see that the sprockets are pretty close together to minimize chain deflection.