Elevation Stats

[Norry1]

OK, so when I map a ride I plan to do, on Mapmyride it gives me a figure showing expected feet of climbing, let's say 3,000 feet

When I then do the ride, my Garmin 705 tells me the amount of climbing that I have done, let's say 5,000 feet.

I then download the ride to Garmin Connect and click the "Elevation Correction" button, this gives me yet another figure, say 4,000 feet.


Please, can someone tell me which figure is likely to be most accurate.

Thanks


Martin

 

[2Loose]

I'd go with the Garmin myself (especially if it was greater )

 

[briantrumpet]

Comparing any of the online mapping sites with my Mapyx Quo, the online ones underestimate the climbing by a considerable margin - something like 30-50%. For instance, my 107-mile Easter Sunday ride had climbing of 1083 metres according to bikeroutetoaster, but 2200m according to Quo. I think this is because the elevation data is at a low resolution on the online sites using Googlemaps or whatever, to make the data processing manageable. Quo has the elevation data for the whole of GB at a 50m resolution, but it's a massively memory-hungry program. When I've compared Quo with official figures given for sportives etc., it's always very close.

 

[PK99]

When I then do the ride, my Garmin 705 tells me the amount of climbing that I have done, let's say 5,000 feet.

I then download the ride to Garmin Connect and click the "Elevation Correction" button, this gives me yet another figure, say 4,000 feet.

The "corrected" version is the better as it links direct to a map, on the road the garmin is working on atmospheric pressure - ok for a rough guide over a short period but pretty poor over a long period - my house is almost always 50-100 feet higher when i get back after a ride!

 

[david1701]

The "corrected" version is the better as it links direct to a map, on the road the garmin is working on atmospheric pressure - ok for a rough guide over a short period but pretty poor over a long period - my house is almost always 50-100 feet higher when i get back after a ride!

barometric altimeters are always innacurate espesh if they haven't had a pressure local at mean sea level reading

 

[psmiffy]

They are all different - it depends what they count as being up and whether it is measured or calculated- every 10m or just anything over 20m -or how many contours do they cross- and as a someone said barometric altimeers can be out over a few hours in changeable weather

My polar and sunnto altimers are always out whewn I get home - but my Garmin Vista is not (allow GPS to calibrater the altimeter)

 

[RecordAceFromNew]

They are all different - it depends what they count as being up

Is this why they say you can freewheel uphill in Australia?

 

[Paul_L]

I too find bike hike to be more accurate than others for elevation data.

For gradients however i've found it underestimates very steep climbs. On hills of known 1:5 gradients i find bikehike has the peaks at 13 to 14 %

 

[Garz]

They will all differ and possibly the most accurate would be a proper OS map judging by the contours or peak info if it has it.

However just like you mentioned I have compared my garmin to the mapping sites and they are not exact. The good thing is if you do the route a few times you could probably take the average of the garmin and take that figure to be more precise.

 

[Norry1]

I tend to use the Garmin Connect figure - one because it is usually in between the other two and secondly because it feels that it should be best - i.e. taking what the 705 actually records and then moderating it against known elevation points.

Next time I do a measured Sportive, I'll see which method is closest to what the organisers state.

Martin