Strava elevation
08-13-12 | 08:52 PM
#1
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From: Grand Rapids, MI
Bikes: Specialized Cross Trail, Specialized Roubaix, Paramount PDG 5, Framed Alaskan Carbon, BMC Roadmachine 01
Strava elevation
I mapped a 70 mile ride last week on ridewithgps.com and it had my climbing at 1700 feet. Rode it with my Strava Ap, and it said 800 feet. Why the big difference.? Are they calculating differently? I also notice when I get done with my ride on Strava it over reports my distance from when it actually ends the ride or run.
08-13-12 | 09:05 PM
#2
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From: Tacoma, Wa
If you're using Strava with a smartphone, then it has to rely on map data to figure out your elevation, but if you go on overpasses or something that often doesn't show up. Also if there are elevation changes or unknown elevations between the mapped elevation levels you'll lose that gain in your summary as well. If you use a Garmin with an altimeter you'll get a more accurate reading.
I'm not sure ridewithgps works though.
I'm not sure ridewithgps works though.
08-13-12 | 09:09 PM
#3
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From: Orange, CA
Bikes: Roubaix / Shiv
Google "richardson effect", or check out https://en.wikipedia.org/wiki/How_Lon...onal_Dimension
Or, imagine you're running, and your body bobs up and down 4cm each stride. After an hour at a cadence of 85, you've gone up and down 5100 times, or 20,400cm. Thats 600ft of elevation gain and loss. Now, does that count? Applied to cycling, imagine bumps in the road, 1 foot here, 1 foot there. Does that count? Who decides? Some algorithms smooth those out, some dont.
Or, imagine you're running, and your body bobs up and down 4cm each stride. After an hour at a cadence of 85, you've gone up and down 5100 times, or 20,400cm. Thats 600ft of elevation gain and loss. Now, does that count? Applied to cycling, imagine bumps in the road, 1 foot here, 1 foot there. Does that count? Who decides? Some algorithms smooth those out, some dont.
08-14-12 | 10:33 AM
#5
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From: Roanoke
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If you're using Strava with a smartphone, then it has to rely on map data to figure out your elevation, but if you go on overpasses or something that often doesn't show up. Also if there are elevation changes or unknown elevations between the mapped elevation levels you'll lose that gain in your summary as well. If you use a Garmin with an altimeter you'll get a more accurate reading.
I'm not sure ridewithgps works though.
I'm not sure ridewithgps works though.
The answer to OP's question is that Strava selectively filters out small elevation changes to smooth the data (to avoid the "Richardson Effect" jmX mentioned). DEM will often NOT have accurate data for roads but rather simple low-res topographic data which doesn't account for roads cutting through hills, bridges, etc. Also, RWGPS uses very little smoothing in their calculation.
08-14-12 | 11:08 AM
#6
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From: Tacoma, Wa
This doesn't make any sense. Both RWGPS and map data are using DEM data for elevation, probably the 30-ft resolution version if you're in the USA.
The answer to OP's question is that Strava selectively filters out small elevation changes to smooth the data (to avoid the "Richardson Effect" jmX mentioned). DEM will often NOT have accurate data for roads but rather simple low-res topographic data which doesn't account for roads cutting through hills, bridges, etc. Also, RWGPS uses very little smoothing in their calculation.
The answer to OP's question is that Strava selectively filters out small elevation changes to smooth the data (to avoid the "Richardson Effect" jmX mentioned). DEM will often NOT have accurate data for roads but rather simple low-res topographic data which doesn't account for roads cutting through hills, bridges, etc. Also, RWGPS uses very little smoothing in their calculation.
08-14-12 | 01:09 PM
#7
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From: Central Florida
Bikes: 2011 Trek 8.4 DS
I used strava for the first time yesterday and when I paused it at the end of my ride and recorded it my time was 1hr 45min 22sec for 27.6 miles. When I looked it up on my computer this morning it had my time as 2hr 8min don't remember the seconds for total moving time. I know the first time was accurate because I looked at my watch when I started and when I finished. Has anyone had similar experiences?
