Strava vs Garmin accuracy

[FirstV8]

I used my gamin edge 25 every day and trust its accuracy to record my distance , time in the saddle and elevation . Today i engaged my Strava as well and was shocked at the difference in readings .  

              Distance    Elevation  Ave.Speed 

Garmin   39.77km         411m       21.77kph

Strava    40.31km         594m       21.98kph

Both times recorded are 1hr 50min so no query on that . My concern is the big difference in elevation . I have always trusted Garmin GPS in the vehicle for many years of travelling throughout SA . Has anyone had this kind of discrepancy and can you explain why ?  

[PieterJvR]

What did you use to measure the ride on Strava?  A phone or was this the figures after you uploaded your ride from the edge 25 to Strava?

[RocknRolla]

edge25 does not use barometric altimeter, so elevation gain is not accurate. 

Not sure on which device you used strava?

[FirstV8]

I use my IPhone . I dont download Strava or Garmin . I just want to know on the day what i have done . 

[Bateleur1]

It all depends what algorythm the various service providers use to calculate the altitude.  RocknRolla already confirmed that the edge25 does not use barometric altimeter which is normally the more accurate measure.  Strava tends to show more elevation than others. 

 

For an example.  Should you cycle over a bridge which crosses a river and say the bridge is 20 meters high at its highest point.   Garmin in its mapping software takes into consideration that you travelled by road and that you just rode level on the road so no elevation gained when crossing the bridge.  Strava however assumes you rode down to the river and climbed out the other side thus you gained 20 meters elevation.

[Dexter-morgan]

Garmin is always, lower than many other devices.

[BigDL]

It all depends what algorythm the various service providers use to calculate the altitude. RocknRolla already confirmed that the edge25 does not use barometric altimeter which is normally the more accurate measure. Strava tends to show more elevation than others.

 

For an example. Should you cycle over a bridge which crosses a river and say the bridge is 20 meters high at its highest point. Garmin in its mapping software takes into consideration that you travelled by road and that you just rode level on the road so no elevation gained when crossing the bridge. Strava however assumes you rode down to the river and climbed out the other side thus you gained 20 meters elevation.

If your phone has a barometric altimeter, will strava use that?

[Frosty]

There was a topic covered on the GCN show entitled, “You’re taking cycling too serious when...”

 

Perhaps this topic should be added to the list.

[Bateleur1]

If your phone has a barometric altimeter, will strava use that?

 

Don't know

[Ozzie NL]

Garmin is always, lower than many other devices.

Uuuh now, Strava app used on phone will typically overestimate ascent vs device with barometric pressure gauge

[scotty]

Different GPS makes and models vastly different reading. As mentioned by Dexter, Garmin tends to be lower

 

Rider’s stats from the 2019 Leige-Bastogne-Leige show just how dramatically different units measure!

 

 

http://fullsus.co.za/cover-feature-measuring-race-routes-how-do-the-get-it-so-ing-wrong/

Edited September 17, 2019 by scotty

[Mamil]

It's a mystery to me too - my Garmin watch reads elevation gain wildly inaccurately (too high) when on my wrist and with variable accuracy when compared to the strava elevation correct feature and I can't see a pattern to predict what will make it inaccurate.

 

In the days when I used an edge 520 and rode with others also using edge 520s, different units would vary by 15 or 20 percent for the same ride. 

 

I understand that barometeric pressure changes all the time but these small units (at least the ones I've owned) don't really seem accurate at all.

[Chingy182]

My weekly Garmin vs Strava activity usually looks something like this:

Go for ride. record activity on Garmin. Upload to Strava. 600m elevation. Log in to Strava. Correct Elevation. Now 1050m elevation. Repeat the cycle next ride...

[BigDL]

Uuuh now, Strava app used on phone will typically overestimate ascent vs device with barometric pressure gauge

iPhones since iPhone 6 have barometric altimeter built in. Just wondering if strava utilises that or map data.

 

Also lots of experience of two identical model garmins in the same ride having 10-15% discrepancy in altitude.

 

Be interesting to know if there is some way to check accuracy?

[scotty]

iPhones since iPhone 6 have barometric altimeter built in. Just wondering if strava utilises that or map data.

 

Also lots of experience of two identical model garmins in the same ride having 10-15% discrepancy in altitude.

 

Be interesting to know if there is some way to check accuracy?

More industrial GPS units which constantly read can be more accurate, Due to limited battery life Bike GPS measure at intervals. 

[Duane_Bosch]

The highest reading is the correct one.