Anyone tried out one of these? For those not familiar, it's a T-shaped thing that can be fixed onto your stem or steerer, there's a long flexible strap that wraps around, and provides you with a place for those extra lamps, computers, etc. that won't go on the handlebar. Useful thing if you have an oval-cross-section handlebar (as my son's bike has) on which many accessories won't fit directly. But: bought one the other day, put it on my son's bike, and on its first outing the screws worked loose and the thing fell off. I was sure I'd tightened them up properly. My son recovered the missing bit but lost the bolt and nut. So now I've tried to re-attach the thing with a standard M5 screw in place of the original allen key bolt. If these things are liable to shake loose on the road, despite normal tightening, this is a design defect, seems to me. I may try threadlock or something. Haven't got back on to the shop yet.