dminor 

Sorry you had trouble with them, Ed. The end caps are a bit futzy sometimes. I wasn't going to say anything before, not because I wanted to hide anything - - I just didn't want to cause trouble where maybe there wouldn't be any for you. The 'trick,' if there is one, is to do the cap with a light touch. The set screw is more to just keep the cap on, not to clamp the grip (the inboard screws do that job). Yes it helps remove the possibility of the inner plastic barrel twisting I suppose, but mainly it keeps the cap on. That means just snugging the screw into it's divot in the plastic (that HAS to be lined up dead on to work right). Over-tightening deforms the plastic, can strip the set-screw thread (yeah, I've done it - - there are, what three or four threads in that cap?) and sets the cap cockeyed on the end.

I like your idea of the opposing set-screw. A divot on the other side and that would be golden. Should be stock from Sunline IMO. For the record, I've salvaged a savagely-ripped-off cap with a small sheet metal screw through everything, bar wall and all. And no I can't believe it can hurt the bar in any way. Shucks it's way out at the end beyond any stresses.

You shouldn't be experiencing any twist though, no matter what. 4 foot to flat? Pffft! I've gapped jumps, cased gap jumps, completely blown gap jumps, augered jumps, gone ass-over-teakettle off stuff and even the crashes haven't loosened the grips. Ripped caps off yes, but the grips themselves have stayed solid.

I feel bad that they haven't delivered as promised though, Ed. PM me and let's see what we can work out.