Originally Posted by tomgdaly
Thanks for all the replies, but I am still a bit confused.
if I get a speed/cadence sensor will it work accurately with auto-lap (by location)? I understand that I can't get splits - all laps will be recorded.
I presume satellite accuracy will vary between tracks depending on the number of satellites engaged etc?
Using the start/stop button isn't feasible for the short efforts, but I can also understand that the data isn't of much use if not accurate.
Auto Lap is guided by the GPS, not the speed sensor, even if the speed data comes from the speed sensor.
The Garmins were made for road riding/racing. Things happen too fast on the track, even the endurance efforts.
The Garmin 500 records once every second. If you are doing high-speed effort (flying 500M or 1K), then you'll need either a stopwatch or an SRM (set to record at 0.5"). You are simply moving too fast to get any meaningful splits from the auto-lap feature.
The SRM is useful because it measures every 0.5" and you can section-off your splits using the software. But, it's still not as accurate as a stopwatch.
Maybe get someone to record a video of your efforts (using a cell phone or digital camera) then you can time yourself with a stopwatch during playback on your computer at home.
Also, note your top speed and finish speed from the file. Those indicators will be just as strong as splits to measure progress.
Originally Posted by gtrob
Roadies can run tempo all year as that's what humans were designed for. If you want to be a cheetah, lay around and lick your paws more.