if your bars are powdercoated or painted, that is acting like nonstick teflon.. clean the coating off where it clamps down.. also get an aluminum 1 piece top clamp, you might have to grind the top edge a little to clear the radio..the one piece steel one hd sells isnt much better..i bought a old dirty used top clamp form an indy for $5,you cant see it anyway

 

When I was running 16" apes this issue would arise now and again for me. I was and still am running a 1-piece top clamp. I tried the sandpaper strip trick, the center punching trick, and sanding down the top clamp trick. All would work for awhile and eventually fail again. The one trick that I did to cure the situation was to drill, tap and use a setscrew in the top clamp over the area of each bottom clamp. Torque clamp to spec, then tighten the setscrew. You could even run a drill in the setscrew hole if you wanted to make a little seat for the setscrew. No problems since.

Adam

 

You can wrap the bars at the mounting points w/ the strips to build up the bars a little and the soft alum. will form and grab the bars when you tighten the clamps down. Strips of old inner tube work also.

 

If anyone has seen the movie The Hangover you will know what I mean when I say I am Re-Tard...the powdercoated placed tape over the knurling in the bars prior to powdercoating...Couldn't see the PC when we installed the bars. Peel tape and problem solved...I hate feeling like a re-tard

 

Glad to see you got it fixed.
Easy mistake to make IMO ......

Did you have to get longer brake lines and clutch cable with the 10's?

 

No need feeling like a retard. They should have removed the tape before they returned the bars to you.

Adam

 

No cables changes for the 10"'s...great bars too

 

Sometimes I've gotten away with changing bars once without getting slippage. Other times, the problem has started from the first change over -- no matter how much I tightened the clamps.

So, my conclusion is that the clamps are a one-time use item. I've re-used torca clamps on mufflers a half dozen times, but handle bar clamps seem to be a one time item.

I also noticed a new Delrin shim for the lower clamp bolts in the parts catalog and wondered if that would make things more solid.

By the way, I enjoyed the homage to "Zen and the Art of Motorcycle Maintenance" in the above comments. It's like Persig's book came alive there for a moment.

 

Mine use to slip on my FXDWG. I just got a pair of latex surgical gloves and cut strips and placed around the knurls. It has worked for 5 years now.