Best motor and drivetrain for large Cycletruck?

[Chalo]

Small pitch chain isn't an advantage for large size chainrings; it is advantageous for large reduction ratios. I used #25 chain on my first e-bike to get a 1:12 reduction in a single stage (12t/144t sprockets). It would have been impracticable to use a 144t sprocket for regular 1/2" pitch chain.

Since you already have some reduction in the planetary gears of your motor, you don't have a strong need for such a large secondary reduction ratio. So you can do fine with regular bicycle sprockets.

 

[Hugh-Jassman]

ok I won't worrie about using a smaller chain.

It looks like the reason my chain keeps braking maybe that the cassette has a warped sprocket. I don't see how to avoid that except to not shift the rear. And use a thicker sprocket there. It has to be only about 26-28t, but do they make such a thing? Only in single speed freewheels.

Then use the front chainwheels to shift for steep hills.

 

[Chalo]

I don't see how to avoid that except to not shift the rear. And use a thicker sprocket there.

No, those things aren't necessary. Just don't shift while the motor is pulling. Modern cassettes can complete shifts under heavy load, but it's likely to damage them.

 

[Hugh-Jassman]

I found an indexed thumb shifter that I can mount on the left side.

To continue my understanding about this, I started another thread about voltage and battery building:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=99952