Discrepanicies in RWGPS and Bike Hike

[migrantwing]

Created a route in RWGPS and uploaded it to Bike Hike to check hill gradient. RWGPS shows two hills on my route, one with a gradient maxing out at 5.9% and another at 6.9%. When I upload it to Bike Hike, these values are 10% and 9%, respectively. 1 or 2% here and there is OK, but what is causing these quite prominent differences?

I've saved these routes as gpx, tcx and fit files, but they are all way off.

 

[migrantwing]

Guess not then.

 

[Crackle]

The base mapping is not to a great scale, so each website uses an algorythm to interpret the data, which is why they vary.

 

[Deleted member 23692]

It all depends on the accuracy of the digital terrain module they use

 

[Nigelnaturist]

@migrantwing try uploading to strava, and create a segment for the whole ride and look at the elevation on it, you find it very close to that if you had created a route on strava.
I have never used bike hike, if I correct my ride on rwgps, my max grade is usually lower than that of the same ride uncorrected, and I generally lose a few hundred feet, which is ok, because this is the data I use for my own database, and the data should be consistent from ride to ride, unless you use a different gps unit, then you may get differences, I know I did between the 500 and the 705.

 

[migrantwing]

Cheers, folks!

 

[migrantwing]

@Nigelnaturist I've looked at the route in strava and created a segment. The two gradients are now showing 9.2% and 14.5% at the highest points. Seems more like it, although I wouldn't say they were that steep. I could be wrong, though.

 

[Nigelnaturist]

@migrantwing the other thing you need to take into account is how often a device records the gps plots, my R20 is every three seconds my garmin every second (though it does have a smart recording mode), the longer betweens plots may level max grades out a little.

 

[migrantwing]

@Nigelnaturist Yes, I've seen some similar segments to mine on Strava and the grades fluctuate between 11% and 15%. It's all very bizarre

 

[Nigelnaturist]

@migrantwing even the same route gives different elevations, even when corrected.

 

[migrantwing]

@Nigelnaturist It would just be nice to know what I'm climbing...or not

 

[Nigelnaturist]

@migrantwing I keep a lot of data, most of it generated from the base info from the unit, in all honesty most is irrelevant, grade I do as a max, but only the corrected one from rwgps, I have a field that shows how difficult a ride is, based on height climbed and distance, height/distance is a good indication but not the whole picture. It does however explain why I am not as fast as last Sept for example, however there are other factors as well, but we all keep things differently, when I am riding I only really look at at my cadence, the unit will show what grade I am climbing at the time but doesn't record it.