I have 16 in apes and when I hit decent size potholes they will move. I have them tightened to spec and they are kurled. Thought about removing the riser clamp and drilling hole front to back and putting a small pin at the desired position and clamping back down. Anyone see any issues with this?

 

Are you sure it's not the bushings moving?

 

Assuming you have the stock rubber bushings in there now I'd try some new poly bushings and see if that makes a difference. The higher the bars the more they tend to move,
You could also try solid type "bushings" but the comfort goes down a bit. Both poly and solid are a cheap fix.
Pegging them, as you suggest, is also an option. I did that a few times on various H-Ds I owned with high bars. That always worked for me.
Good luck with your fix.

Acky1946

 

You can also take a large grit sandpaper, fold it in half so the grit is showing on both sides, wrap that around the bars and put your top clamp back on. I have had good luck with this taking a lot of the movement out of my bars.

 

i wrapped grip tape on the knurled part of the bars under the clamp. sandpaper works too

 

I have changed the rubber bushings and it's the bars that roll in the clamp when I hit bumps in the road. Not all of the time but enough to **** you off.

 

Put some drag bars on her. Problem solved!

 

Skateboard grip tape worked perfect on my 16's. My bars are rock solid now.