How do you calculate how far you've climbed?

[OakLeaf]

The Garmin Edge series has a barometric altimeter, software corrected against known locations, and are considered the most accurate bike computers on the market. Barometric is WAY more accurate than GPS points, just because of the nature of the triangulation from satellites high above the ground, and with the correction against known points, it eliminates some (but not all!) of the inaccuracies that come from air pressure variations.

The software programs I mentioned, MotionBased (online) and SportTracks (downloadable) add another level of correction to uploaded GPS data. MotionBased does tend to overestimate, it seems. SportTracks has my confidence mainly because it (1) reliably corrects distances on the occasions when there's a problem with my GPS; (2) gives elevation figures in flat terrain that seem pretty reasonable, when everything else will really overestimate just because of little pressure variations of a foot or two at a time; (3) usually matches total ascent and descent pretty closely for a ride that starts and ends in the same place; and (4) can vary in either direction from my raw 705 numbers rather than consistently being higher or lower.

Just looking at topo maps, as you point out, is probably reasonably close for long steady climbs and descents, but in rolling terrain, most of the climbing won't even register on a topo map that's laid out in 200 foot contour lines. Surely yours must be narrower than 100 meters!? In areas where the climbs are short but very steep, like Ohio, climbs of 150 foot (50 m) gain at over 10% grade surely do count in your legs. So it depends on where you are I suppose.


ETA: for real-time grade, there's a very low-tech bubble level type of device in the Adventure Cycling catalog. It doesn't store data obviously, but for just glancing down and seeing how steep the hill is that you're climbing at the moment, you don't get any more accurate than a gravity-based device!

[SadieKate]

The Garmin Edge series has a barometric altimeter, software corrected against known locations, and are considered the most accurate bike computers on the market. Barometric is WAY more accurate than GPS points, just because of the nature of the triangulation from satellites high above the ground, and with the correction against known points, it eliminates some (but not all!) of the inaccuracies that come from air pressure variations.

The software programs I mentioned, MotionBased (online) and SportTracks (downloadable) add another level of correction to uploaded GPS data. MotionBased does tend to overestimate, it seems. SportTracks has my confidence mainly because it (1) reliably corrects distances on the occasions when there's a problem with my GPS; (2) gives elevation figures in flat terrain that seem pretty reasonable, when everything else will really overestimate just because of little pressure variations of a foot or two at a time; (3) usually matches total ascent and descent pretty closely for a ride that starts and ends in the same place; and (4) can vary in either direction from my raw 705 numbers rather than consistently being higher or lower.

Most excellent explanation! I may steal this sometime.

kfergos, do a search on SportTracks and you'll see some discussion of the plug-ins which make SportTracks such a tremendous application.

[hilldweller]

Just looking at topo maps, as you point out, is probably reasonably close for long steady climbs and descents, but in rolling terrain, most of the climbing won't even register on a topo map that's laid out in 200 foot contour lines. Surely yours must be narrower than 100 meters!? In areas where the climbs are short but very steep, like Ohio, climbs of 150 foot (50 m) gain at over 10% grade surely do count in your legs. So it depends on where you are I suppose.

Thanks for that detailed reply Oakleaf. I think I'm starting to get an idea how they work now. The NZ topo maps have contour bands at 20m (60-something ft) intervals, which is pretty detailed really. I'll have to see if I know anyone with a Garmin or something similar and see how much difference all the little ups and downs makes. Could be quite a lot on rolling terrain. As you say, depends what sort of roads you're riding.

[msincredible]

I use:

Bikely, which does calculate total climbing. It works well on some routes and not so well on other routes (according to my estimates and to friends with Garmins).

My VDO cyclocomputer which just uses barometric pressure. If the weather is nice all day, it does pretty well, but it gets easily confused in all our microclimates. Climbing in the rain the other day, I suddenly saw myself on a 54% grade!