chain banging into upper support arm?

[Cam]

Hi all i have put togther one of these kids and after i few rides i noticed that the chain was taking paint off the upper support bar above the sprocket from the chain moving sidways i have re tensioned the chain and made sure that tensioer didn't move during the ride by marking points to see if the tension-er slid but it didnt. note im running a rag join mount for the sprocket any ideas on how I could solve the problem of the chain grinding on metal as that will cause the chain to snap.

many thanks

 

[wolframore]

It would be nice to see pictures, is it possible you’re using a dished sprocket? Perhaps you should have it dished the other way. Since we can’t see what’s going on it’s just a guess.

 

[Chainlube]

Put a washer on the inside of the drop out to space the sprocket further in.

 

[Will'smotobikes19]

If its a 2 stroke, which probably is. You can use a spring loaded tensioner from the sprocket cover and use the basic design one on upper bar to keep it from rubbing.

 

[Cam]

here I have put 3 washers to space out the support arm from the sprocket. Also do u think i could mount the chain tensioner upside down pushing the chain away from the top arm. and I am using a dish sprocket .