Originally Posted by topflightpro

I had an issue with a cheap, generic, K-Edge-style GoPro mount causing interference with my PC8. I was getting frequent power drops on only one of my bikes, and by removing that mount, my problems went away. I'm not sure whether the metal had some magnetic properties or what. SRM seemed surprised when I got back to them to tell them that was the problem. I ultimately discovered it because when I first contacted SRM about my problem, they asked if I was on a TT bike, in which the aerobars might block the signal. I was looking at my set up and thought, "huh, I wonder if the GoPro mount is causing interference." (I only had the mount on the bike in which I had the power drop problems. The other bike did not have problems or a mount.) I stopped, pulled out my mini tool, removed it, and the problem went away.

And adding more anecdotal evidence to the pile, I've heard several people complain about issues with Stages, Pioneer and Quarq. (I went through three Quarqs in 18 months. My wife, knock on wood, has had no issues with either of her Quarqs.) I've heard that Vector is not particularly accurate. The only ones I don't hear many power-related complaints about are SRM, Power2Max and PowerTap. That said, I did buy a Stages for my wife's second bike. It was too cheap to pass up, and she is only riding this bike a couple times a month.)

InfoCrank has gotten good review so far, but there are so few of them out there, I think it's too early to tell.

But if you are looking for a 170 DA Pioneer, I know a guy selling one. He wants to go back to 172.5.