Picked up the mount today, great quality and 30 seconds to fit - seriously. I'll add some photo's, but basically, no need to replace the top nut, or even remove it. The guy makes these in his workshop, along with fittings for most bikes, even has custom ones where two devices can be fitted such as lap timers and a camera. The ball uses is a 1" Ram ball and he me chines the other parts.
The one for the panigale has a rubber lip which is pushed down hard so as it cops through the hole in the nut, it has an alu disk which sits on top and you just tighten it up so as the rubber lip that's now under the nut tightens up. It's designed to stay in place, but could be removed by unscrewing completely, the rubber section should then fall straight through.
Mine is on and will be staying in place, the looks don't detract from the looks of the bike and always handy to fit the sat nag or GoPro to for rides out.
I'll put a link to the web site where they can be ordered directly if anyone fancies one. Cost wise, they are £28.50 + £3.50 UK postage, or can be picked up from the Cheadle Heath area of Manchester. He would post international, but not sure of the price. May be worth combining with others to get a reduced postage for international if a few people want them.
