Originally Posted by streners
My only thought would be if the hub axle had a hole in it for the screw in the chain tug to pull against. That way it would try and pull the hub back, keeping the tension of the chain up. Is this how it works?
Well, you've got the right idea.... A chain tug actually has a plate where an axle end pokes through. Chain tugs are attached at the axle ends prior to mounting the wheel into the dropouts. The set screws/bolts pull the axle rearward and keeps it there, then of course, you tighten the nuts.
My take is as long as you're using quality track axle nuts and washers, these gizmos are not necessary. I always set my chain tension by feel and my wheel never slips.
George