I have this chain tensioner problem and fix it with spring. The spring must have high tension. ..but not that high to resist the tensioner from moving. .the chain might pull the tensioner inside to the wheel but it will be pulled back by the spring. Hope this helps. Any suggestions? you may comment below. I you have problem with chain jumping of the sprocket you may check the alignment of the chain. For me I elevate the wheel sprocket with the use of thick washers.