80cc on a sun baja cruz?

[Antilia]

I have an older Sun Crusher which is now called the Baja Cruz Coaster Break. After I purchased my engine I realized the issue of the chain not fitting on the 26 x 3.5 inch tire. I was looking into a jackshaft but I feel like it adds so much complexity. is there a way to move the chain out from the same side just a little bit, just like a jackshaft but for the same side.

 

[curtisfox]

Not much info. What do you have for sprocket mount? If rag joint, a sprocket adaptor you have some side to side play,maybe enough...........Curt

 

[Antilia]

I would like to use a rag joint for my sprocket mount, i only need to move the chain over maybe an inch to make it work. Is there something on the market that will do that? Will provide pictures later after work.

 

[indian22]

Fab a jack shaft & add a wide sprocket hub adapter is the quick answer. That is if your frame is large enough to mount a jack shaft as you described it, and if your wheel hub will accept a hub adapter for 3 hole sprockets. Really need photos of the bike and closeups of the rear wheel hub to answer your question. Also what diameter is the rear hub? Is the 80cc engine a Chinese 2 stroke kit motor? Otherwise we're just guessing what you're dealing with.

Rule of thumb 2.5" tires about as wide as you can go without it getting somewhat "complex" which means different things to different builders. The rag joint won't clear wide tires, even with the widest hub clamp sprocket adapter that Curtis mentioned won't clear a 3.5" tire without additional spacing.

Clearing the tire with chain is only one aspect of making this work with a wide tire as the new chain line has to be perfectly straight with the motors output sprocket and also clear the seat stay tube and chain stay. The chain cuts like a saw on both rubber and metal components while even a slightly crooked chain line will cause the chain to jump sprocket or break.

Rick C.