Elevation differences?

Cardinal-Red

Hi, started a new thread, because didn't want to hijack Pedarby's one on calories, but me and a friend did the same ride together last week, and logged two different elevations of Strava, 1014 foot for me and 705 feet for him, over the same distance of 35 miles.

Strava even linked the rides together and I've checked the routes and they match.

I used a Garmin 1000 and he used the iPhone app.

So what's the cause, and which is likely to be most accurate?

Cardinal-Red

Ignore this - I've found the 1000000 google hits on the same topic.

Interested in views as to which is more accurate though - I did the elevation correction on Strava and my elevation went up (slightly) just widening the gap between the two.

sloppyschleckonds

I wouldn't trust Strava data for anything

grenw

Me and the missus ride together with 2 different Garmin Edges (me a 510, her an 810) and every time I get around 10% more climbing in. Neither are adjusted by Strava - this is straight off the screen.

Of course, mine is the accurate one!

On a more serious note, the Garmin will have in a barometric sensor so should be reading off changes in air pressure. The iPhone I assume is reading off mapping the same as Strava would. Not sure this answers which is more accurate though.

thomasmorris

In the UK strava will be more accurate, abroad, probably garmin.

Garmin is generally accurate but the barometer is very sensitive to changing pressure and water blocking barometer hole.

Strava is based on map elevation data... so where they have good mapped data it's good. But on the continent I've had obviously very bad results.

In the UK i tend to correct elevation on all my rides, as that seems more consistent.

wongataa

thomasmorris wrote:

In the UK strava will be more accurate, abroad, probably garmin.

Garmin is generally accurate but the barometer is very sensitive to changing pressure and water blocking barometer hole.

Strava is based on map elevation data... so where they have good mapped data it's good. But on the continent I've had obviously very bad results.

In the UK i tend to correct elevation on all my rides, as that seems more consistent.

Strava just use the freely available elevation data which is the same quality in the UK as in mainland Europe and it is pretty low resolution and full of glitches. As an overview it is fine but for details it is not so good. They do not use higher quality OS elevation data as it is expensive.

The iPhone will be using the GPS for the elevation. The Strava app won't be pulling down elevation data. All it does is record the GPS position every so often. If the Garmin is set to 1 second recording then the recorded track on the Garmin will be more accurate than the one on the iPhone.

thomasmorris

Okay, that goes against my experience then. Across the UK when I have auto corrected the route profile is exactly as I would imagine including the height so the peaks and sea level (checked against OS). It often matches up perfectly with the elevation profile I get when I put the track in memory map (OS elevation).

However, in Southern Spain and Italy when I've auto corrected it has produced a saw tooth profile. Looking at the full profile it's hardly noticeable, but when you zoom in on the analysis you can see it.

(edit: having said that, on the rides in Italy (2012) and Spain (2013) I was thinking of, I can no longer see this).

sniper68

I have a Garmin 820 and my lad has an Edge 200 and we get massively different stats on the same ride.
If I plot the same route on Memory Map I get the same elevation stats as I do from Strava after doing elevation correction so I tend to go with the data that Strava comes up with.
If I use elevation correction on Garmin Express it's still differs from Strava/Memory Map.
Having said that they could all be wrong!

N0bodyOfTheGoat

I'm getting wildly different stats from my Nexus 7 2013 tablet and new Sony Smartwatch 3 when I take them both out, mainly in terms of max speed and segment time, but also elevation.

I'm trying to see if different recording apps give more similar data on the watch compared with the tablet, but trying to make sense of it is a nightmare! Generally, I'm finding the watch's standalone GPS disappointing, I can start Ghostracer and it might take 15-30 minutes some days to get a GPS lock!
The standalone Strava app might be working better on the watch.

It doesn't help I recently bought a Polar H7 monitor and I'm currently trying to evaluate the Polar Beat tracking app on my tablet, which then sends the ride and heart data to Strava.

... Too many cycling apps!

Jerry185

Even worse: when I was visiting my girlfriend and had forgotten to take my Garmin. We did our runs together then she saved it to a GPX(?) file on her computer. I logged on, downloaded the GPX file onto my Strava in the approved manner and, taadaa, different speeds and elevation.