As I was just riding along (JRA) this morning, I kept hearing a beep. Not constant, just occasionally. My watchs beeps on the hour, but that wasn't right. My combo cyclometer/heart rate monitor (Specialized p-Brain) beeps to alert me that my heart rate is out of my pre-defined zone. I'm not a morning person and was definitely feeling pretty sleepy, so was almost wondering whether I'd worn my chest strap transmitter and had forgotten I'd done it. Nope.

Then I realized it was my LIGHT sending interference to the heart rate monitor receiver! It's getting a bit darker every morning now, and I finally put the light on the bike. When it was no longer quite so dim out, I turned the light off, and, sure enough, the heart-rate component of the cyclometer clicked off.

Funny to see my heart rate in the 160s while heading downhill.

Lin