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

It's been 38 days since my crash, and things are progressing, but not as fast as I would like. There was progress 1.5 weeks ago when I got a massage @ World Gym, which left me feeling good, then a productive acupuncture session last Wednesday, which also helped. This initiated a ramp-up of my physical activity. I did 10 minutes on the trainer on Thursday morning followed by a resistance training session in the evening where I was able to up the effort significantly from my previous one. While none of these exercises caused pain, I was left feeling quite fatigued, and waited for the bus rather than walk up Potrero Hill afterwards. Friday and Saturday I was still tired. My walking was definitely off compared to how it had been on Thursday. Despite this, I wanted to stick to the trainer rides, so on Friday I did 20 minutes, then Saturday I did two rides, one of 10, the second of 20 minutes. I figured my fatigue had been from lifting, and the riding was good. Unfortunately Sun

One issue in using VAM to predict power is the effect of variation in grade. I looked at this back in November, 2009 . Grade variation leads to speed variation (at constant power) and speed variation results in an increase in energy dissipated to wind resistance. The analytic result I got was: Δ p / p 0 ≈ 3 f [ < Δ grade ² > / ( grade 0 + C RR )² ] × [ ( 1 - f ) / ( 1 + 2 f ) ]² where f is the fraction of power from wind resistance, <Δ grade ²> is the variance of grade with respect to time (this is to first order the variance with respect to position), and C RR is the coefficient of rolling resistance. Using iBike data from a ride up Old La Honda (iBike directly measures grade, rather than indirectly via altitude), I concluded at constant power up Old La Honda the grade variation would lead to a 0.44% increase in power. I can convert this to the effect on VAM by multiplying by the fractional effect of power on VAM : Δ VAM / VAM 0 ≈ 3 f [ < Δ grade ² &

This Tour de France has experienced truly epic increases in people calculating how much power riders generate on climbs, typically towards assessing whether Chris Froome is practicing illicit performance enhancement. One of the more popular practioners of this assessment is VeloClinic, for example in his Haiku-esque Tumblr page . In previous years, there has been a good deal of discussion about VAM, Ferrari's statistic of rate of vertical ascent. Since climbing primarily involves mass overcoming gravity, VAM is related to power/mass, but but it's only a crude instrument, since the more gradual the climb, the greater the fraction of power going into wind resistance and rolling resistance. Additionally, it is possible to sustain higher VAM for shorter climbs compared to longer ones: on shorter climbs you can use your anaerobic energy reserves more rapidly, increasing the energy per unit time, which is power. Furthermore, at higher altitude oxygen concentrations in the atmos

Today I rode the trainer for the first time since my crash a month ago. I borrowed Cara's cyclocross frame because it's small and I can more easily get my leg over the top tube. Previously leg mobility was limiting on me being able to get on the bike, but today I tried and I could do it. Pedaling has also been a concern but I was able to turn the pedals without too much problem. The limiting factor is more muscular than aerobic: I did just a few minutes today. But that's a starting point. I've also been going to the gym, doing light weights, and I think that's helping, even if it leaves me tired. I see my general practitioner tomorrow, the first time since my crash, so maybe he can give me some advice on my progress. In Tour news, it's been all Froome. I realized last year, his first year on Sky, that I'd seen him years before.

L'Equipe recently posted a nice article on the history of time trialing, including the hour record. The posting included a wonderful photo of Jacques Anquetil , an unsurpassed time trialer in the history of professional bike racing. Jacques' peak was the late 1950's and early 1960's. He won the Tour 5 times, perhaps with the assistance of blood transfusions in the later years. Anquetil was famous for his extreme toe-down pedal style. It's typically recommended the foot at the bottom of the pedal stroke be at a relatively shallow angle, for example 15 degrees. But Anquetil's foot was at a much steeper angle: closer to 45 degrees. It's hard to argue this approach slowed him down at all, but I've not seen it imitated by accomplished racers. The dominant time trialist of today amomg the ProTour ranks is clearly Tony Martin . His most recent victory is the first individual time trial in the 2013 Tour de France , which is ongoing as I write this. De

Since the mid-naughts SF2G has served as a catalyst for cyclists to commute from San Francisco to the Peninsula. The focus has been Google's Mountain View campus, but I've never worked for Google, and I've ridden with the group to Stanford Campus, my old office on California Ave in Palo Alto, and to my present work-place south of Google at the Mountain View - Sunnyvale border. There's no leader; instead riders call rides via the Google Group , then others affirm their intent to join with a Googlesque "+1". But until now, despite the fact SF-to-Peninsula is considered a "reverse commute" (although with the flight back to cities from suburbia this is changing), there's been no comparable organization of cyclists who work in the city and live on the Peninsula (the "forward commute"). That changed today with the launch of a new group, "Pen2SF" . They also have a web site (still under development as I write this). I really

Its t injury +26 days, and I'm still hobbling around. Generally I'm hobbling better than the day before, but not always. I'm not working from home any more, instead braving my Caltrain commute with its close to 1 mile of walking each way (assuming I take the MUNI 10 bus and the VTA light rail in Mountain View). I can do this but it's tiring. I have more functional strength in my adductors on the right, injured leg. I can do push-ups. Getting on and off a bicycle would still be an issue. I've not thought much about riding since last Thursday: I was in Martha's Vineyard and was able to straddle a small hybrid bike, but pushing off with the injured leg just seemed too hard. I'm overdue to try again, but since I live on a 17% slope, the barrier to entry is higher. No "quick spins around the block". Virtually every road in Potrero Hill of San Francisco is steep. It's frustrating. I've gone to acupuncture 4 times, and while it

There's now three minimalist pedal systems on the market, as I pointed out in a previous post : Aerolite : the original, from 1979, very early days for clipless pedals. Cleats are set up for 4-hole mounting, like Speedplay but with a different spacing, although they can also be mounted in 2-hole (mountain bike) shoes or 3-hole (using 2 of the 3 holes). Ultralite Sports : I became introduced to these at Interbike last year: very slick. They have a novel clip-in, clip-out mechanism. TriRig Mercury : still in limited release, closer to the Aerolite than the Ultralite Sports, but with 3-hole cleats rather than 4-holes. Aerolite makes 3 models of pedal. The lightest is "time trial" version with holes drilled in the Turcite sleeve which surrounds the axle, and also the spindles have minimal length to keep the feed close to the bike, which was considered more aerodynamic back then. Then they have a "criterium" pedal, also with short spindles, in this case no