Originally Posted by
Seattle Forrest
I have a Garmin GPS watch for hiking and running and swimming, and also an Edge computer. My experience is pretty much like yours. I have to go about 30 miles before they disagree by 1/10th mile.
OP and some people's expectations of what you can get out of consumer devices is unrealistic. Expecting every source to match even more so.
In the example above, if you assume one of your devices was 100% correct, then the other one was about 99.67% correct. But that is assuming you and your wife rode the
exact same track which is unlikely. If you go wide on 10 corners, that could account for a 500 foot difference. Even so, if I got slightly different numbers from 2 units on my handlebars, I wouldn't worry about it. We used to ride with little wheels that ran off the tire to measure miles to the nearest 10th. So a Garmin is magic* in comparison.
Originally Posted by
CliffordK
Anybody know how Strava uses and records time? I've had the time off on my android phone by quite a bit, and it all seems to work out just fine. But, would other devices be more sensitive to the proper time? Having the time off by a minute or two could give a bizarre "flyby" summary, but really wouldn't affect the overall ride at all.
Most cell phones seem to use the time broadcast by the provider. In the past, I found that at&t was off from the real time, but that doesn't seem to be the case anymore.
The time on any real GPS unit is going to be correct to the second (actually a lot less, it's critical to how they work.) Cell phones have GPS chips in them, but I can't see that they're used to set the clock.
*Any sufficiently advanced technology is indistinguishable from
magic. -Arthur C. Clarke