Strava v Radar
07-28-16, 09:44 PM
#1
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Strava v Radar
Wasn't quite sure which forum was best for this, but figured I'd get the most abuse here. On my commute home today I passed one of those radar contraptions that tells you your speed. It said 18mph. Checked strava on my Apple Watch and it was 15.6mph.
Who's lying?
Who's lying?
07-28-16, 10:43 PM
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Wouldn't use Strava as a speedometer. I've found my computer to be pretty consistent with radar signs.
07-28-16, 10:49 PM
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Between those two I'd trust the radar sign. But I'd trust a simple magnet-based cyclometer with correct wheel size setting over either of them.
07-29-16, 12:21 AM
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I use my Garmin watch on the bars and there's this radar on my way back home. Those two readings jive with each other.
07-29-16, 04:02 AM
#6
Flyin' under the radar
There's no real way to know. RADAR units have to be calibrated periodically, so it could have been an inaccurate reading. Besides, there could have been a data transmission delay between your phone and your watch, so you might have actually been going 18mph but the data on your watch hadn't yet caught up.
In terms of speed detection accuracy, I'd rate it accordingly:
1. As @prathmann mentioned, a wheel sensor (properly setup) is the most accurate.
2. RADAR
3. GPS-based cycling computer
4. GPS-based phone app
5. Time divided by distance
In terms of speed detection accuracy, I'd rate it accordingly:
1. As @prathmann mentioned, a wheel sensor (properly setup) is the most accurate.
2. RADAR
3. GPS-based cycling computer
4. GPS-based phone app
5. Time divided by distance
07-29-16, 04:26 AM
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I'll just add that my Garmin Edge shows ride elevations that are always short of reality. Example: I do a ride that shows 2300 ft. of elevation and it's really 2600 ft. Other Garmin models are more accurate.
07-29-16, 06:12 AM
#8
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Strava polls GPS data once per second and extrapolates data based on two points. Not reliable for a single point in time reading.
07-29-16, 06:24 AM
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07-29-16, 06:43 AM
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07-29-16, 07:07 AM
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07-29-16, 08:09 AM
#15
Flyin' under the radar
07-29-16, 08:17 AM
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This.
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See, this is why we can't have nice things. - - smarkinson
Where else but the internet can a bunch of cyclists go and be the tough guy? - - jdon
07-29-16, 08:24 AM
#18
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My experience is that radar usually reads ~1 mph low compared to a Garmin (with speed sensor). I think probably just due to the angle between the radar and the direction I'm traveling.
07-29-16, 08:38 AM
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Who the heck has time to look at a radar when passing it, much less also look at your watch/computer and then compare the two?
I mean, even at my leisurely 500 watts, I blink and it's like loooong gone. Didn't even see it. Radar? What radar?
I mean, even at my leisurely 500 watts, I blink and it's like loooong gone. Didn't even see it. Radar? What radar?
07-29-16, 08:42 AM
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07-29-16, 10:42 AM
#21
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Using cell tower triangulation to determine location is even more unreliable and something Strava would not have access to anyways.
07-29-16, 10:52 AM
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07-29-16, 10:57 AM
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07-29-16, 11:12 AM
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07-29-16, 11:18 AM
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Yes, many phones have real GPS that's further assisted by tower triangulation. That said, I've found my Garmin to be far more accurate.