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

This is yet another in a series of the Low-Key Hillclimbs Portola Valley Hills multi-climb day. We used GPS to time riders based on when they were interpolated to have crossed a series of "lines" (essentially passing through virtual pylons) in the correct direction. Between certain lines there was a time budget which was designed to be easy to meet, as long as you didn't dally. The lines were designed to be wide enough so all riders who rode the course would be credited with crossing all of the lines, even in the presence of GPS errors. It all worked so well in testing. But in practice, on "game day", the conclusions from testing proved optimistic. First I'll look at time budgets. I had provided a lot of slack in these, and I needed it. There's two major reasons for this. One is that the test riders were mostly solo. On the other hand the "event" riders tended to ride in groups. With group rides the faster riders would wait at the top...

This is another in a series of the Low-Key Hillclimbs Portola Valley Hills meta-climb. It was the second climb where Low-Key used custom timing code to extract rider times from GPS data. But it was by far the most complex, since instead of one climb where time was the difference between the time at the top and bottom, it was a series of 5 climbs where the times from each were added. I did preliminary testing of the Portola Valley Hills course with 6 data sets of riders who had attempted to pre-ride the course. One did the climbs in the incorrect sequence, leaving 5 riders which the scoring code processed. I had no problem with these riders. But it's a big difference between processing 5 data sets and processing 70. Here I'll look at the GPS tracks I recorded for each of the climbs in the Portola Valley Hills. First, the good. Here's plots for the three climbs ending at appropriately named Peak. The plots are x versus y, where x and y are the distance eastward and ...

There were a number of challenges with organizing the Portola Valley Hills Low-Key Hillclimbs . For example, the Edge 500 GPS quality on Joaquin Road. But one of the more interesting was the scoring conundrum represented by a rider who repeated one of the climbs. The scoring code I used here was originally developed for Kennedy Fire Road last year . There we had a long climb with a number of intermediate check-points. To get an overall time I assigned a time to each checkpoint, but overall time was essentially the time crossing the finish minus the time crossing the start. If the rider completed the course multiple times I'd keep track of times between the start and finish and take the shortest one. If a rider recrossed the start line I'd start over. If he crossed the finish line I'd ignore everything until he recrossed the start line. It was easy. For Portola Valley Hills I added in the cocnept of time budgets for time segments between checkpoints. If a rider ...

Back in 2010 I did a regression of the Tour de France total length since WWII. There was a clear overall trend of course length reduction. In the 1920's, a typical route was 5500 km. By the 2000's that had decreased by 2000 km. The effect of this was profound: the Tour went from an ultra-endurance event with stages starting hours before dawn, unable to sustain body mass, to one where riders are able to devote considerably more time to recovery each day. Since then I like keeping tabs on the distance to see how it's doing relative to that trend. After all, while most of the public focuses on the final 20 km of each stage, it's the up to 200 km preceding that which provide the real character of the event, wearing down riders and teams and tapping into the human body's endurance limits. Without those preceding kilometers, the Tour loses some of its character. Even with the pack still together, it's what I call the "unseen attrition" of the effort....

I couldn't believe what I was seeing when I got an email from Bicycling magazine promoting an article which discusses Strava's responsibility in Kim Flint 's death in June 2010. The article is here . It spawned an even more remarkable set of comments arguing Strava had responsibility in Flint's fatal crash, which resulted when he went after a downhill KOM in the Berkeley Hills. There was a law suit resulting from the crash, pressed by Flint's family, and Strava won. The result of the crash was Strava's segment flagging policy, as well as a beefed-up user agreement bludgeoning the potential user even stronger with the idea of personal responsibility and the inherent danger of the roads. It additionally resulted in Strava's Stand With Us policy, calling on users to support it's vision of friendly competition with personal responsibility. Here was my response to that Bicycling article: Any argument that Strava should take responsibility for removi...

To further test the Low-Key timing on the Portola Valley route, continuing the work of the previous two blog posts, I decided to check the distance covered by 4 riders who completed the course on trial runs. The following is a summary of these results: checkpoint description avg dd sigma dd 0 Golden Oak E beginning 0 0 1 Golden Oak E midway 572.859 3.28549 2 Golden Oak W finish @ Peak 593.25 2.61963 3 Joaquin start 7727.13 266.924 4 Joaquin finish 562.262 11.2647 5 Hillbrook pre-start 5183.68 206.595 6 Hillbrook start 40.9188 1.80053 7 Hillbrook finish 509.026 16.7473 8 Cerventes start @ Kiowa 1377.76 24.602 9 Cervents finish @ Peak 633.005 7.36351 10 Golden Oak W pre-start 2113.01 61.9842 11 Golden Oak W start 27.0102 3.06064 12 Golden Oak W @ Toro 1023.98 3.93379 13 GOlden Oak W Peak 341.193 1.71231 14 Summit Spring start @ Trip...

I tried to find the San Francisco Transit-First policy and indeed some old links were stale. I dug it up again at this link . But it's sort of flaky, so to give myself a chance of finding it again, I figured I'd just copy it here. The transit-first policy of San Francisco is brilliant for its time, as it was passed in the dark ages of the 1970's. But unfortunately even though we consider ourselves now far more enlightened, the policy is typically ignored. Compliance is by convenience, not by intent. In any case, that it persists in the city charter gives continued hope for the future. We now realize the focus on the car in the mid-20th century nearly killed our cities as virtually all new infrastructure investment was in suburbia, a failed, unsustainable, unscalable model. Today demand for cities is higher than ever, and with a half-century of neglect, supply is inadequate. As a result the most expensive housing in the nation is in urban cores. Cities are cooking ...