I have no earthly idea why these things are knurled.,because I can't get a grip to stay on it without eventually slipping down, if my life depended on it. The hairspray trick didn't work, 3M spray gave up, shit, I even used the adhesive sheet that came with some Avon grips that I ordered. I don't want to use a permanent glue but it looks like I don't have a choice. BTW, a little alcohol on the clutch side (smooth chrome bar end) and a day to dry and it's never moved! Biltwell, make some smooth ones!