Happened to me 2 miles into my trip home from the dealership when I bought my 2012 Fatboy Lo 2 Months ago. I wasn't used to the bike and not very experienced on street motorcycles. Scared the hell out of me. I was on a side road doing only like 40. You should have heard me yell at them on the phone when I got home. Lol

 

i lost a lower tree mounting bolt on a chopper once going about 30mph.the bars swung sideways.. had a 12" over springer just to make it more fun. the only brake was on the handle bars. with a lot of luck, i kind of Fred Flintstoned it to a stop. happened to be passing a indy harley shop so i got a new bolt and borrow a wrench.. def not anything i ever want to experience again..

 

I have to check and tighten my top clamp bolts about every third ride. They slowly loosen all the time. I was recently told by some guys on the forum that the metal the MoCo uses in the risers is not the best quality, so it doesn't hold the thread well. I just stripped a bolt, so my Sunday project is to Helicoil that riser. I have heard of some guys that put a small strip of 150 grit sandpaper between the bar and the riser also, so I think I will try that while I have the bars off.

 

My Carlini "Boob Risers" have a hidden set screw. With the aggressive knurling Bill put on my bars, they do not move.

I don't move my bars around, but if I did I'd use blue loctite as Tx_Outlaw posted.

 

I have read somewhere that you can pin the bars drill a hole in the handlebar then drill a matching hole in your riser one or both risers put in a dowl pen they will never move on you again those aps do move around a bit the bigger the ape the bigger the problem

 

You could try cutting a rubber glove into strips and wraping the strips around the bars and using blue locktite on the bolts.
Thats worked for me on other bikes that didn't have knurled bars or set screws in the risers.