This morning was also my first ride with my new HRM setup. I got the sensors put on the bike last night and had a go playing with downloading files to the computer. Everything is terrific . . . except for one thing. For some bizarre reason, Polar decided not to include an Auto Stop/Start feature on their top of the line cycling computer. I have absolutely no clue why they would decide to do this. It's commonplace on even the cheapest cyclocomputers and it's very important. I freaked out last night when I found this out, but fortunately it's not as big a deal as I expected.

The average speed calculation was what I was most worried about, but fortunately it throws out samples taken at zero speed. That means that the average speed I get is the same as an auto stop/start. So the only real missing piece of information is ride time. The stopwatch now runs from the time I start it to when I stop it. There's nothing to tell you how long you actually spent moving. I can deal with that, however, so my plans of eBaying the HRM won't happen.

Another piece to note is that the average speed calculated from the dowloaded file by the PC software differs from the average speed seen on the watch immediately after I finish riding. I emailed Polar, expressing my displeasure with not having auto stop/start, and also asking about this difference. Here was their response, which amazingly came in less than ten minutes:

Dear Mr. Brewer,

Thank you for your email.

The software use samples in all calculations and displaying information whereas the HR monitor uses online data. Thus the values in the HR monitor and the SW may vary a little. However, when using the recommended 5 sec. cording rate the differences are minimal or do not exist. However, the heart rate of a lap is an exception: the heart rate at the lap is the same in both the receiver and software.

It confirmed what I'd already assumed. The watch does some averaging on its own and throws out the zeros as well. The software uses only the samples taken every 5 seconds. So essentially, the watch takes more samples when calculating the on-board average. This usually means that the watch's average is a few tenths of a mile/hr less than that of the software. I can live with that. I will miss ride time though.