here's my thatsdax kit installed

or you can lay a bolt flat behind the bottom of tensioner and using hose clamps on each side to hold the bolt in place and this will keep the tensioner from going into the wheel.
this works on mine.

If there's a better chain tensioner I'd like to know about it myself. I finally got my Dax kit installed and the tensioner wheel pulled off the side of the bearing. It seems awful flimsy and poorly designed. I would like to get a shifter kit but can't spare that much cash right now.

I too had a problem with that POS stock tensioner. I don't like drilling into the cross arm as I would think it would weaken it and these bikes are not meant for this kind of abuse. I found this thread on a pretty good idea for a tensioner.

Spring Return Chain Tensioner

that looks like a VERY good idea and design. very little required to make it work.

I was engaging my engine and the tensioner went into the back wheel. 3 broken spokes later and a severely bent wheel I came to a stop. thank god I was only going a few mph. I will be taking the advice of the above thread and get myself this tensioner. I already have the 41 chain.