Originally Posted by
jrobe
I wonder how accurate some of these inexpensive altimeters really are though (or for that matter, even the expensive ones). It is useless if it isn't accurate. Are they accurate on rolling hills, etc?
I wouldn't trust the cumulative gain figure on any of them in terrain that's basically flat but with lots of short ups and downs. They all use some internal filtering to reduce the amount of noise in the raw altitude data and the details of the filter will have a big effect on the result in that type of terrain. And if they didn't filter at all then the result would be way too high.
But they can be pretty good when you have a ride with a few major climbs.