Sprocket help QS138 70h v1

[azeus17]

My son and I are converting a Coleman CT200U using a QS138 70h v1. It has the tapered shaft. I did not realize when I bought it how difficult it would be to find sprockets. The motor came with a 428 sprocket and the bike uses a 420 rear. I am having a heck of a time finding a new sprocket for either end to make them compatible. I've looked through the Amp website and did not see a 420 sprocket for that motor. I find the Supersprox website very unhelpful, unless you need a sprocket for a year and model of a factory bike...no dimensions or really descriptions at all. I've searched all over Amazon, etc. for a 428 rear sprocket that will fit that bike, but no luck. I've even considered a 520 as I can find a front sprocket for the motor, but not for the rear.

Any other ideas out there? If I can't find something, I guess I'll have no choice but go custom.

 

[Chalo]

My son and I are converting a Coleman CT200U using a QS138 70h v1. It has the tapered shaft. I did not realize when I bought it how difficult it would be to find sprockets. The motor came with a 428 sprocket and the bike uses a 420 rear.

ANSI #40 chain might be able to reconcile those two different sprockets. The width is enough for the wider sprocket but the roller diameter is close to the smaller size. It's probably worth picking up a piece of chain and test fitting.

 

[azeus17]

Thanks for the suggestion...I'll check it out!

 

[Hummina Shadeeba]

Are there any pulleys available that fit the qs138 motor shaft? I find the chain stretches quickly and takes time retensioning vs a belt