I bought the Procycle bar-end mirrors, installed them, then drove down North Vancouver through heavy traffic to try em out at the dirtpile in south Richmond (Triangle Park?). They come with what looks like solid aluminum clamps but what in reality is pot metal. One of the clamps broke during installation. The instructions say " do not over-tighten" but who reads instructions? Motorsport will send me a new clamp to replace the brocken one. In the interim I used JB Weld to mend the fracture.
The mirrors provide a wide-angle view of what is behind and are great for moving through traffic. They do not seem to twist out of position when going over bumps, and are easily folded out of the way. Their only downside, other than the crappy metal used ito make the clamps, is that the wide-angle view makes vehicles behind very small and hard to see unless they are up close. I did not see the police car behind me until his lights started to flash. The ticket price was much more than that of the new hardware!