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Showing posts from November, 2013

Bike Brands at the Low-Key Hillclimbs

Starting in week 5 I began asking riders to describe the bike they were on when they RSVP'ed for the following weekend's Low-Key Hillclimb. We used to write this down at check-in, but it made it a lot easier to search the data if I had it entered digitally. So if we had a rider on a red and yellow bike and couldn't identify him I could search for all descriptions with both "red" and "yellow" for the bike and realize there was only one such description. We also ask for jersey color, but still write that down at the start, since I for one have problems planning this sort of thing ahead of time. But maybe others plan their wardrobes better, so I may add jersey description to the RSVP form as well. But anyway, I decided to check what bike brands people were riding this year. So for rider numbers for whom I had a bike description (one per rider, so not counting the same rider multiple times if he rode multiple weeks), considered his bike description and

Low-Key Hillclimbs 2013: personal report

Another year of Low-Key Hillclimbs has come and gone, ready or not. When the series began in the first weekend of October I had been riding again for two months (Aug-Sep) after missing most of June + all of July to a groin injury from a bike crash. My focus during this period was on physical therapy, however, and my ride tended to be short and low-intensity. My progress from late Aug - early Sept took a step back when I devoted riding time to watching America's Cup racing. I started ramping up again at the end of September but I was nowhere close to where I needed to be. I traditionally coordinate Montebello, week 1 of the series, and this year was as usual. Weeks 2 and 3 I volunteered, riding climbs both weeks in advance of the participants in order to take split times along the course (Montevina + dirt week 2, Bohlman week 3). These were good, solid, hard climbs, and were a nice boost to my fitness. I added an Old La Honda Wednesday Noon Ride late October, finishing just

Low-Key hillclimbs consolidated results pages

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I am a firm believer that old event results matter, and am always dismayed when I check for results of some past event or race and can't find them. The half-life for old results tends to be around 2 years: typically you can find last year, but go back two years, and it's 50-50. Since a big motivation behind Low-Key Hillclimbs was to show how things can be done better, I've made an effort to keep old results easy to find. With this in mind, I've long had a vision that results should be in some sort of queryable data base. For example, want to find the best scores for women in the 20+ category? No problem. I can do that: I have command-line tools which allow me to quickly search a CSV file of scores from the entire series history. But to provide an on-line access to that would be nice. But that would be a lot of work. As an intermediate step, I decided to write Perl code which would generate static HTML of the consolidated results for every climb Low-Key has do

history of Low-Key Hillclimb banners

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I've been organizing the Low-Key Hillclimbs, with one extended break, since 1995, and as a cycling event it has always has always had its existence firmly planted in the internet. It was relatively early in that regard. Web design hasn't really help up with the times, however. The pages are relatively simple HTML, although I indulged in some JavaScript in 1997, even with on-line ordering for T-shirts. I've only recently started using PHP, and only for Strava API interaction. I want to move toward more PHP in the future, but for now the HTML works fine. One feature of every year is a banner image. Banner images are rather dated these days, but I still like them. Here's a brief history of the Low-Key Hillclimbs banner image. One note: the 1995-1998 pages were reconstructed, since they had been inadvertently lost. 1995-1997 were regenerated with original graphics, but 1998 was generated fresh in 2008 from 1998 result data. So the 1998 banner image is circa ten year

VAM analysis of climbing Marin Ave in Low-Key Hillclimbs 7X Challenge

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Marin Ave isn't like most other climbs. With Marin, it becomes as much a matter of survival as of speed. Speed is desired as much because it ends the suffering sooner as because of the desire for any target time, placing, or Low-Key Hillclimb points. Yet in the case of Saturday's 7X challenge of course the placing and the points were still important. A nice thing about metrology data is they tell a rich story if examined closely enough. In this case I didn't have a power meter, my PowerTap too heavy for timed hillclimbs, so I have to rely on other ways to judge my effort. On a climb this steep, VAM is a nice proxy for power, so I use that to judge my pacing. VAM extracted by numerically differentiating measured altitude with respect to time is inherently noisy, especially on a Garmin Edge 500 where altitude is reported with 1-meter resolution. So to get meaningful numbers I convolved the result with a Gaussian of sigma 3 seconds. This smooths the VAM to something w

Low-Key Hillclimbs week 7x: timing Marin Ave with GPS

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Saturday was a double event of sorts for Low-Key Hillclimbs. We had the standard climb, up Lomas Cantadas in the Berkeley Hills, but we combined that with a bonus event, to do Lomas and Marin Ave, in that order, in the same day. We called it the 7X Challenge . The climb of Lomas Cantadas was fun. I felt stronger than I had the week before, at Patterson Pass. The pace was very quick at the start, requiring a level of explosiveness I simply do not have now or maybe ever, and I drifted back. This cost me a bit on the short descent, where I was in slower traffic than the leaders, but I did well on the final steepest portion, passing riders who suffered from having stuck closer to the leaders in the early going. Among the riders without electric assist, I was 9th, a very good result for me this year, given my ongoing physical therapy to recover from my June crash and injury. I helped with the finish line crew to get the numbers of riders finishing after me, then headed over to the p

Low-Key scoring and X-weeks

Low-Key scoring got complicated when we started balancing the contributions from each week. The results from one week can affect the results of other weeks. This is fine. There's several goals in the scoring: the average of all rider scores should be 100. rider scores should be as consistent as possible week-to-week if I plot the logarithm of scores versus the logarithm of times in a given week, I get a straight line, the average slope for all weeks being one. A trivial example for this might be the following: Suppose rider A does climb 1 and gets a time. He's the only rider in climb 1. Climb 1 has been the only climb. He gets 100 points, consistent with the first goal. Now rider A does climb 2 and gets a time. Again he's the only rider, but now there's been two climbs. He gets scores of 100 and 100. This is consistent with goals 1 and 2. But suppose now I realize there was also a rider B in week 2. Rider B was 20% faster than rider A. Using the third goa

polyline checkpoint enhancement for GPS timing during Low-Key Hillclimbs

As I initially described here , I have been developing an event model for GPS data for the Low-Key Hillclimbs. This allow us to do things which weren't possible before: dirt climbs: 2012 and 2013 , where it's better to let riders do it on their own short-hills routes , where there's too many time points for practical hand-timing bonus climbs , supplementing the standard "event", in which riders get a chance to experience more challenges A limitation of the model has been checkpoints are defined as fixed line segments. This provides a much better solution to event applications than does the Strava timing algorithm, which is optimized for users who within a few seconds define an arbitrary, abstract "segment" and the code is left to match rider data to the segment without much additional information. My model is set up for a course designer who is willing to carefully optimize the placement of a series of checkpoints, to improve timing accuracy and to

Low-Key Patterson Pass: small groups and the prisoner's dilemma

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The prisoner's dilemma is a description of a problem where you have two suspects are captured, accused of committing a crime, and are isolated in separate cells. If either admits to the crime while the other does not, the prisoner admitting to the crime is set free, the other given the most severe punishment (10 years in prison). If they both confess, they are given a light, 2 year sentence. If neither confess, they are held in prison for one year, but eventually freed for lack of evidence. So if you're one of the prisoners, what do you do? If they could collaborate, then the best approach would be for neither to confess. They'd esch serve a year in prison, which isn't great, but overall they'd serve only two years. That's much better than the alternates. But they're isolated, so they can't collaborate. For each prisoner, what the other prisoner does is beyond their control. If the other prisoner confesses, then he is better off confessing as

Letter to Supervisor Cohen on Potrero Streetscaping project

I went to a public meeting on the Potrero Streetscaping project . The principal opposition was from those who fear the loss of parking along this busy, dangerous, high-speed road, which was formally the major through-road along the eastern boundary of the city until that function was taken up by highway 101. Here's my letter to my supervisor, Malia Cohen , which I hurriedly dashed off this morning before riding to physical therapy: Supervisor Cohen: I was at the public meeting last night ont he Potrero Avenue streetscaping. The core issue is the priority our transit-first city is going to place on private vehicle parking versus MUNI efficiency and pedestrian and cycling safety. MUNI is bogged down in traffic and pedestrians and cyclists are being picked off on our roadways at an appalling rate. It is thus imperative to the quality of life in the city that this project moves forward. The key requirement is that traffic on Potrero Ave slow down. The median landscaping, by

How I voted in Nov 2013 San Francisco Election

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Usually I like to post summaries of my views on ballot measured, etc, before elections. After all, if we just vote in silence then we get just one, barely significant vote, but it is in discussion of the issues that voters have their real power. However, this election I slacked off, and I post this after I already voted and the polls have closed. This was the smallest election I remember, certainly in San Francisco, maybe anywhere. There were no contested races, 4 city ballot measures, and nothing at the state level. Turn-out will be extremely small. Here's how I voted on the ballot measures: Prop A : Yes. This is a restriction against tapping into city employee health care accounts for other purposes. Actually I didn't look at the nitty gritty details, and honestly I'm not sure how effective it will be, but it has a lot of support and seems like a good idea. Prop B : No. A condo development along the waterfront wants an extension of the normal height restrictio

GPS accuracy comparison using Portola Valley Low-Key Hillclimb data

As I noted, when dealing with GPS problem cases in the Portola Valley Short-Hills version of the 2013 Low-Key Hillclimbs, I couldn't help but notice every one of the cases I grappled with was an Edge 500. This is anectdotal, so I wanted to take a closer look at the problem. The initial plan was to scrape the HTML from the Strava pages with a Perl app, since the API doesn't provide computer type, but when this didn't work out for me since Strava requires user authentication to see this info bit I started thinking about PHP options but finally when I couldn't sleep last night I just went to the pages sequentially and transcribed the computer identifier from the browser. Brute force. Not elegant. I feel so dirty. There were 69 riders @ Portola Valley who each reported the URLs of their Strava records. I then compared these using the root-mean-square average of the distance from the center of the lines the riders triggered the lines (units: meters). The ideal number

Low-Key Hillclimbs: trends in rider turn-out

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As we head into week 5 of the 2013 Low-Key Hillclimbs, the trend has been unambiguous: despite excellent weather, rider counts are down since last year. The climbs are just as good as ever, although perhaps so far on the challenging side. Still, comparing the same climb year to year the conclusion is the same. And with SRAM leading the way first with compact drivetrains and then with wide-range rear cassettes, riders on "racing bikes" have access to lower gears than ever before, making the steep roads less intimidating. I plot the trend here. 1995-1997 it became more popular and then peaked, dropping off in 1998 when the series took a break. It came back in 2006 and had to rebuild a following almost from scratch. 2006-2010 There's a clear peak 2006-2009 was a period of rapid growth, but then it saturated, with a clear drop-off in 2012 which has accelerated this year. One hit for 2012-2013 has been the "GPS-timed climbs." These have a lower turn-out t