Page 1 of 1

the 'water in the hole' problem

Posted: 16 May 2016 10:18
by Andy Terry
I am now the proud owner of a Garmin Edge 810 and last week got caught in a downpour and I think experienced the 'water in the hole' problem. The Garmin did not register any altitude change on the long and wet 500m descent.

Anyway ... is there any way of preventing this?

Posted: 16 May 2016 10:55
by AlanW
Don't go out in the rain?

Joking aside, as I understand it, on the right hand side of the Strava screen where is shows the elevation data, if the word "elevation?" is in blue and underscored you can click on it and it will then calculate the elevation based on the route ridden and then correct it. But, you can only do that once and if it corrects it incorrectly it cannot be reversed.

Although, thinking about it, if you still have the .fit file on your Garmin what would stop you deleting the ride from Strava and downloading it again?

Posted: 16 May 2016 11:22
by Andy Terry
Sorry my question wasn't clear ... but I think I found the answer anyway - fit a Garmin Edge 800/810 Silicone Case.

http://www.wiggle.co.uk/garmin-edge-800 ... cone-case/


Regarding Strava - I think it works out elevation from route anyway and ignores what is in the FIT file. Which also explains why it exaggerates massively in mountainous terrain.

Posted: 16 May 2016 11:47
by AlanW
Sorry but the case makes no difference, in fact I think that sometimes it makes it worse as it tends to hold water rather than let it blow/flow freely away

Posted: 16 May 2016 11:56
by laurence_cooley
Andy Terry wrote:Regarding Strava - I think it works out elevation from route anyway and ignores what is in the FIT file. Which also explains why it exaggerates massively in mountainous terrain.
If the Garmin is one with a barometric altimeter, Strava takes the data from that (unless you press the correction button): https://support.strava.com/hc/en-us/art ... r-Activity.

Posted: 16 May 2016 13:00
by Andy Terry
laurence_cooley wrote:If the Garmin is one with a barometric altimeter, Strava takes the data from that (unless you press the correction button): https://support.strava.com/hc/en-us/art ... r-Activity.
Only if you upload direct from the device (which I don't) so it can detect the presence or otherwise of the barometric altimeter. If you upload via GPX (which I do) it doesn't know you had a barometric altimeter and sp recalculates elevation using SRTM database.


Other Known Issues and Problematic Terrain:

The elevation profile has climbs, but the elevation gain is very large. This often happens with activities recorded in mountainous areas outside of the US.


As I thought. Strava calculated 21,000m of climbing for my week in Corsica - it was actually more like 13,000.

Posted: 16 May 2016 13:05
by Andy Terry
And just to add, my old faithful eTrex 30 records elevation accurately - rain or shine.
:)

Posted: 16 May 2016 16:48
by CakeStop
This happened to me when I was caught in a storm weekend before last. Strangely, it actually added a huge hill where the storm started in the flat lands of Earlswood. The correction feature got rid of this but resulted in the elevation being understated compared to a correctly working altimeter.

Posted: 16 May 2016 19:03
by petemarshall
The cases don't work.
It usually only gets blocked in a real downpour not "normal " rain.
As far as Strava goes it uses the data uploaded to it this includes how it was recorded as all this is contained in the file, makes no difference if it's a fit or gpx format or how it's uploaded. Strava will over ride the data from the file if you click on the correct data button replacing it with map data. This is usually more accurate in terms of actual climbing than the GPS record of altitude dependent on how often it samples, but not as accurate as barometric.
Whilst weather changes can cause odd jumps in the profiles of climbing shown on Strava this doesn't effect the overall climbing recorded as long as you set your edge to pause.

Posted: 18 May 2016 12:15
by George
Silicone covers can also interfere with attaching the unit to some types of mount.

I'm slightly surprised to read the above, because I've now been using a Garmin in all weathers for some years and I've never experienced a problem. Am I simply very lucky? Does everyone who has experienced a problem have a missing/worn hole plug?

Posted: 18 May 2016 12:31
by petemarshall
George wrote:Silicone covers can also interfere with attaching the unit to some types of mount.

I'm slightly surprised to read the above, because I've now been using a Garmin in all weathers for some years and I've never experienced a problem. Am I simply very lucky? Does everyone who has experienced a problem have a missing/worn hole plug?
Hole.plug? The tiny hole for the barometer must be open or I assume it doesn't work.
I haven't had a problem with my 810 but did have the problem once on my 510..
I try and avoid riding in real bad downpours and use mud guards in the winter. I also use an out front mount that may shield the unit a little.
The hole is on the bottom of the unit and placed centrally by an out front mount which does mean it should get less water thrown up from the road than handle bar mounts which place the unit to one side.

Posted: 18 May 2016 12:47
by George
Sorry. I had the wrong end of the stick. Ignore my comment about hole plugs.