Questions about Acerbis Hand Guard Installation: I got a set used with a used bike I recently bought. No instructions came with them. So obviously I cut round holes in the grips and bolted them to the bars, two points per side. The problem: the allen bolts tighten in the bar ends expanding the two slash-cut expansion ends against each other but they spin inside the bars and never really tighten or lock into the bar ends? Are they supposed to be able to be pulled out by hand or is there some problem and they are supposed to be tight and locked in place? They just spin when I tighten them and the bolt gets hot from the friction. What am I doing wrong? Thanks!