On Bicycles, and.... what else is there?

Today I'll take another look at the route data from the Death Ride , Climb to Kaiser , and the Terrible Two . Here for each climb I first map the data onto a 50 meter grid, then slightly smooth it using an estimated 15 second time constant (the same as when I calculate a climb rating), then I map it back to a 50 meter point separation (since smoothing disturbs this at the beginning and end of the ride) then I calculate the total climbing (with zero threshold) between each pair of points on the route. For each segment length (which is the number of contiguous points minus one multiplied by 50 meters) I find the segment which maximizes this total climbing. The only efficiency trick is if I have a given segment length, I don't need to calculate it fresh each time: if I start with the segment from points 1000 to 2000 (length 50 km), and I want to calculate the climbing from points 1001 to 2001, I take the previous sum, subtract the climbing from 1000 to 1001, and then add the ...

Last time I used grade histograms and total climbing versus climbing threshold to compare three really solid one-day riding challenges: the Death Ride , Climb to Kaiser , and the Terrible Two . What I left out is sort of the obvious: the route profiles. Every big ride shows its route profile, and they all tend to sort of look the same: up and down. So to compare the three, I plotted them on the same axes. I use km for distance and meters for altitude: That one's worth more than the measly 100 kpixels shown here, so if you click on the plot you should see a higher resolution version. Anyway, the Death Ride and Climb to Kaiser look sort of imposing here. The Terrible Two is almost lost under the giant altitudes of those other two rides. Climb to Kaiser is perhaps most striking of the three, starting down in the lowlands before rising to and beyond the lofty altitudes of the Death Ride. Indeed, Climb to Kaiser is a very special ride, one I often recommend to those who th...

First, a bit about the climbing algorithm. Just two paragraphs, I promise. Then on to good stuff. I just described an algorithm by which you can calculate total climbing from a route profile with a given "climbing threshold" designed to both eliminate small bumps which can be coasted over, but more importantly to get rid of the small altitude fluctuations which occur with "noise" in both barometric and GPS-based altimeters. I proposed that a 5 meter threshold worked well, but that there was no unique answer for what is the "true" climbing of a route. Well, that algorithm does work well for a relatively small climbing threshold, but when you crank the threshold up to the size of the largest hills on a ride, it can be fooled. For this post, I thus added an extra step to the process, in which peaks closer than the climbing threshold from the minimum altitude on the ride, and valleys closer than the threshold from the maximum altitude on the ride are b...