I like the bmx chain, and have had success with KMC Z510 HXYour options are
(1) Get a thinner tire
(2) Get a thinner chain. I use this really strong BMX chain, it gives me more room for the rear tire, it won't break and it won't get twisted after extended use, also, it seems to go through my engine sprocket with less drag than the bulky 415. ---> https://www.bike24.com/p272230.html
Also here---> https://www.starbike.com/en/wippermann-connex-chain-1r8-complete-nickel-plated-112-links/
(3) Remount engine at a different angle.
(4) Get some kind of sprocket adapter that will move the rear sprocket away from the hub.
Yes I am using a rag jointAre you using a rag joint? I cut some spacers from 1/4 in. pvc. worked well an have put many, many miles on it. View attachment 99863
What kind of hub are you using? Do you have a coaster brake or freewheel?Yes I am using a rag joint
I have a freewheelWhat kind of hub are you using? Do you have a coaster brake or freewheel?