Originally Posted by freewheeling frank
the dropouts on the cranbrook are facing forward, i dont use a tensioner on mine. but the torque pulls the axle forward lossening the chain i plan on building some adjusters like on a motor cycle when i get time till then i carry a wrench in my back pocket and tighten it up as needed.
I doubt that's what's happening. Out of dozens of bikes set up that way never saw an axel slip. It really can't happen if tightened properly. More likely the chain is wearing.