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 ...

For Low-Key Hillclimbs week 4 riders must ride a series of short hills, and we add up their times on those hills. The intent is that riding between the hills not be included, but we don't want the riders to head out for lunch between climbs, the intent is that the ride be continuous, providing some test of endurance over short hills as well as peak power. So to allow for that there is a time budget to get from one hill to the next. But if a rider needs to wait for a friend to finish the preceding climb, takes a wrong turn, or even has a puncture and does a fairly quick tube swap, we want the rider to have time to complete the transition. So the times to get between the climbs have been generously allocated. Additionally, Low-Key gets a broad range of riders, including unicyclists in the past, and so it would be a mistake to set these time limits for the fastest riders and compel the more endurance-oriented riders to take stupid risks to avoid additional time being added to th...

For Low-Key Hillclimbs week 4 this year, we're doing a GPS-timed route which I have been told is similar to something which has been used in rally car races: the riders must follow a somewhat challenging route, doing a series of short climbs in a given order, where the net time is calculated as the sum of the times taken to get up the hills with any time taken to get between the hills if those are over the allowed budget. So if there's two hills, and there's a budget of 10 minutes to get from the top of the first to the bottom of the second, then if the rider takes 8 minutes to cover the gap, there is no time assessed for that, but if it takes 12 minutes, that would add 2 minutes to the rider's total time. The ideas is that the time be based only on the climbs, but that the rider make a reasonable effort to get from one climb to the next in a timely fashion. Key to all of this is to time the rider between checkpoints. I define checkpoints as one would in most races...

After coordinating week 1 of the Low-Key Hillclimbs last week, I was a volunteer for week 2, with the role of taking split times where the course transitioned from paved to dirt. It was a fun climb, mostly on paved Montevina Road, but then the riders traversed a barrier and continued the last half-mile on fire road. To get there, I of course rode. So with a small backpack and on my trusty steel Ritchey Breakaway, I set off ahead of the riders to be in position before the leaders arrived. This was to be my longest hard climb effort by a factor of two since I injured myself, and came after riding to work on back-to-back-days, that coming after a hard workout in the gym and physical therapy. Hardly what would be classified as a "pre-competitive taper". But despite this, I went out at a power pace (around 280 W avg) which would have been solid for me up Old La Honda, a substantially shorter climb than Montevina, at my peak fitness. Not surprisingly, this didn't la...

I came across the following interesting tidbit on the CyclingNews review of the Trek Speed Concept 9 : To tweak the original Speed Concept, Trek engineers studied real-world wind conditions on Ironman courses, and settled on optimizing the bike for yaw angles between zero and 12.5 degrees. (They found 3-5 degree average yaw in Arizona, up to a 13 degree average yaw in the notoriously windy Kona worlds course.) I came up with my own ad hoc calculation, including the Hellman model for ground shear, back in 2011. I published that here : So the end result of all of this is that, given the assumption of an average 10 mph wind at 10 meter elevation (a stiff wind), a Maxwellan distribution of the ratio of wind speed to rider speed, an average rider speed of 11 m/sec (40 kph), and a Hellman coefficient of 0.34 (associated with urbanized areas), I get the average yaw angle magnitude is 6.8 degrees, with yaw probabilities extending from -20 degrees to +20 degrees. The yaw of greatest probab...

In my previous post, I noted that Strava segments can be flagged by a single, perhaps overopinionated, observer. Convinced a flag is unjust, other users redefine segments for essentially the same path. These new segments are typically flagged as well. This process may be further repeated, leading to a littered mess of redundent, flagged segments. The obvious response is for Strava to allow segments to be unflagged. However, they need to be careful here, since it may well be the case if anyone can unflag a segment which had been flagged, enough users exist that persistent segment flagging could become essentially impossible. This would nullify the role of crowd-sanctioning that flagging is designed to play. There are segments which are intriniscally dangerous to contest, and Strava doesn't want to be found responsible for promoting dangerous competition. So a balance is needed. But it doesn't take much imagination to derive a way to reach it. It's a matter of ti...

Yesterday I took advantage of an oh-so-precious closure of Conzelman Road in the Marin Headlands to ride the backside of Hawk Hill. While the road was "closed" in the sense of auto access, it was open as never before to hikers, walkers, and cyclists. The "closure" really revealed the potential for Conzelman Road, normally a congested, traffic-clogged tourist trap where drivers work their way through the numerous parking hotspots until they reach the top, get out of their cars, snap a few photos, get back in their cars, and battle the crawling traffic back down. This is all because the National Park Service, which oversees the Headlands as part of the Golden Gate National Park, operates under the policy that human legs are vestigial atavisms, and the only sort of meaningful human access is car access. Fortunately the people, young and old, enjoying the wonderful and rare serenity of the hill yesterday didn't buy into this 20th-century myth. I, as did severa...

I rode Hawk Hill in the Headlands today, and what an eye-opening experience. Rather than a traffic-clogged photo-op, it was a peaceful vista to be savored and enjoyed. Walkers, hikers, cyclists were going up and down the hill, all smiling at the rare opportunity presented by the Federal shutdown... the shut-down of a national park service that is so car-centric it views "access" synonymous with "car access". I went to the summit then started descending the backside of Conzelman. As I turned a corner I saw two women slowly climbing the other way. My first reaction was "they're crazy", until a few seconds later it occurred to me... why not? The "narrow" road is plenty wide enough for bidirectional bike traffic. So when I reached the bottom I turned around and climbed it myself: ouch, that is steep. It's an opportunity I'm not likely to get again. I strongly recommend checking it out. It's a chance to envision the pote...

Thanks to Will Van Kaenel for this great image, from Google Earth. Low-Key Hillclimbs begin Saturday!!!

It's been three and a half months since my crash in June, and while I continue to progress, it's been a lot slower than I originally expected. Strength is improving thanks to Physical Therapy (@ Potrero Physical Therapy , supplemented by plenty of work in the gym ), and my cycling is getting stronger after a break for some travel and watching America's Cup. My Strava plot tells the story (distance in km): Note the short distances from late 2012 were from a focus on running versus cycling. I can run short distances (very short) but even a half mile running to the gym last week left me slightly hobbled for a few days. I'm definitely looking forward to getting my running legs back, as I very much miss trail running. Cycling is going better. While my right side is uncomfortable pedaling, it's not painful, and I'm more limited by lack of aerobic fitness and endurance than the injury. I've not yet done any extended climbs (more than 1100 vertical feet),...

The finish of the 2013 World Road championships was remarkable. There's something special about Road World Championships, with riders representing nations rather than trade teams, in a winner-takes-all scenario in which the winner always worthy, but where circumstances and luck play a substantial role. In this case, after the crashes had filtered down the field, it came down to four riders: Nibali from host Italy, Costa from Portugal, and Rodriguez and Valverde from Spain. Obviously Spain had a big advantage with two riders who could win. Rodriguez and Valverde have been like twin brothers the past few years. Despite riding for separate trade teams it seems like they're always together. But the past few years Rodriguez has been the stronger. And world championships was no different. With two riders in the final four, Rodriguez launched. This put the team in an excellent position, as Valverde could just follow the wheels of the other two. If Rodriguez were to stay away...