I wanted to test some bar end mirrors and found some bar ends of the right diameter from an older project. However, there is no good way to secure them to the V2 bars. So I manufactured a little retaining mechanism. The thread inside the bar matches perfectly a 1/4" NPT thread. I had some 1/4" NPT socket head caps (they are available on Amazon, cheap), so I drilled holes in them, then made threads using 6mm tap. The caps screw in deep into the bar, and creates an anchoring point, and the bar end now can be secured to it using the 6mm bolts. I prefer this over friction type mount. Sharing here if anyone is interested. Using this method allows pretty much any bar end to be mounted securely and aesthetically.