I had to send my Garmin 305 back for a warranty repair. I decided to buy a Garmin 500 as sort of an alternate, so if and when my 305 is in the shop, I'll still be able to anally retentively collect data.
I always figured GPS must be pretty accurate. No more wheel calculations, wires, magnets, easy transfers from one bike to the other.
Well Doug and Mookie shattered my impressions with stories of Garmins inaccuracies in both mileage and elevation gain.
So since I have two units now I decided to do a little test. I used them both simultaneously. I had the 500 on my stem and the 305 in my jersey pocket.
The 305 recorded a further distance, but less elevation gain and a crazy high calorie burned.
You would think the unit on the stem would have the higher mileage count? Or that two units would somewhat closer on elevation? Or what kind of whacked out algorithm are the using to calculate calories, and why the 1300 C difference?
They keep pretty good time though.