I don't know where/how I tried setting them up on my trekking bars. It's been too long. I wasn't happy with the view I was getting. My wife tried it on her flattish/slight rise bars and complained that all she could see was her armpit. I tried them on my old-school swept back handlebars and on my trekking bars. The swept back bars worked best with them, but in all cases I found it a little awkward to use just because I had to keep my head and the mirror at the right angle to see behind me, and, of course, I had to be going straight. That's not the fault of this mirror, as it's probably a factor with any handlebar-mounted mirror, but at the time I was also experimenting with an helmet/eyeglass-mounted mirror, and I ended up deciding that I liked that a lot better.

I still like the idea of a handlebar-mounted mirror. The helmet mounted one goes against my general trend of trying to make the bike(s) as complete as possible and ready to ride with no extra gear/preparation on my part. A mirror not attached to the bike means that sometimes I hop on the bike and find I don't have a mirror, but that's rare because the mirror now lives almost permanently on my glasses, and it's just so much handier than other mirrors I've tried. So it really wasn't the mirror's fault, although I didn't think it was a great match with the trekking bars, it's just that I found a mirror solution that I liked better.