Analyse a ride
Drop in one ride file and read what it measured: the road cut into the climbs and descents you would actually name, the power you held on each, and your drag area with the spread the estimate saw. The climbing comes off the ground rather than off a barometer. Your file is read in your browser and never uploaded.
Drop in one ride to see what it measured.
Everything here is a measurement, which is why one file is enough: the time, the road, the power and your drag area with the spread the estimate actually saw. What you will not find is a reason — a cause is always a cause compared with something, and one ride has nothing to be compared with. Two files answer that, in the comparison.
Because there is nothing to have lost it to. Every cause on this site is a cause relative to another ride, and with one file there is no other ride. Inventing an average rider to compare you with would produce a number, and it would not mean anything. Put two of your own rides into the comparison and every cause is priced with its uncertainty.
From a terrain model of the ground under your route, not from the altimeter in the file. A barometer cannot tell four hours of weather from a hill — on a flat island ride one reported seven hundred and fifty metres of climbing on a road with thirteen metres of relief. Your file's own figure is shown beside ours so you can see the difference.
From the energy balance over every stretch of road long and steady enough to carry it: what your power went into, once climbing, rolling and the air's density are accounted for. Weight is anchored and rolling resistance held, because a ride cannot separate all three at once. The band beside it is what the estimate itself found, so it is honest about roads that could not say much.
Because a ride of climbs and freewheeled descents flatters its own average. Normalised power weights the hard minutes far more heavily than the easy ones, which is closer to what the effort actually cost you. On a steady flat ride the two figures nearly agree; the bigger the gap, the more stop-start the ride was.
Yes. Distance and speed are taken from your file, and your head unit measures them from a wheel sensor when it has one and from GPS when it does not. GPS wanders under trees, in cuttings and through switchbacks, and it cuts every corner, so a ride without a sensor reads a little short and its speeds a little rough. A wheel sensor with the right circumference set is the more accurate of the two, and every figure here that is measured per kilometre is measured better with one.
The file is read in your browser and never sent. The numbers decoded out of it go to the server to be worked out, and nothing of them is kept. The map loads its tiles from a map service, which can see the area of the ride and nothing more.