I was reading on another forum about a dirt-bike guy(old post)running a narrow x-ring chain.
He said it "pogo-jumped" ?? I'm just going to guess he meant in the chain slack?
The guy wrote that he 'fixed it' by using a hacksaw to cut-out & removed all the x-rings in the chain,then it was 'fine'?? weird
The rubber rings had become packed w/ dirt??