I had Genmar risers and never had them move even though I tried to on a few occasions. Now I have Convertibars and have them at the highest position which is +3 inches over stock...beyond that I have the bars raised an additional 1/4 inch in their clamp and the fork clamps raised up the fork tube another 1/4 inch...thus giving me an additional 1/2 inch over what the bars are supposed to provide.
Result, I cannot get the bars or the clamps to move at all. I have tried many times to get the bars to move...they simply won't.
I'm certain that even under conditions that far exceed the normal the bars are going to stay where they are.
Slightly different item, but I also had a YZF 750 with the Two Brothers adjustable riser bars on it...and even during a crash that ground a large portion of the bar weight off the bars never moved...in fact the bike was perfectly ridable after a lot of duct taping 60% of the body work back together and having to shift with my hand for about 30 miles through the mountains due to a broken shifter.
Once at the hotel more permanent repairs were made and the trip continued. A drill borrowed from the maintenance guy at the hotel, a bolt, a lock nut, some locktite and the salvaged rubber from the old shifter fixed the shifting issue. Lots, and lots of duct tape, a slight concussion, a new helmet, some gloves, some mirrors and a few other replacement part found at local bike dealers and the trip was able to continue...BTW total bill for the bike repair was $4,500.00...90% of it was simply body work.