Tuesday, December 30, 2014

Vector pedal stroke analysis metrics available

Fulfilling a long-term promise, the Garmin Vector now does pedalstroke analysis! See DC Rainmaker's excellent blog post on the latest firmware update.

The new metrics include:

  1. pedal force offset: this measures how far outboard or inboard the average force is applied.
  2. pedal power stroke: this measures over which angles peak propulsive force is applied
  3. seated versus standing time: if you're standing, the pedals support full body weight (non-propulsive), so the Vector can determine how much time you're standing versus sitting (and record whether you're standing or sitting).

Various applications for these metrics would be bike fit, technique analysis, and interpretation of performance. For the pedal force offset, that obviously suggests a bike fit application. "Power stroke" suggests both fit and technique. Standing versus seating suggests performance analysis: am I faster seated or standing on short steep climbs? What about long sustained climbs?

More data is almost never a good thing. The key is how to act on it.

On fit, saddle height optimization is an obvious application. Can I see some signature in the metrics of the saddle being too high? Does the power stroke compress as the bottom of the pedal stroke becomes less accessible when the seat is too high? Does the top of the pedal stroke becomes less productive when the saddle is too low? I don't know.

My key objection is that the update is provided only for the 510, 810, and 1000. For me, the 500 is the best unit most of the time: it's the most compact, the lightest, and it's relatively easy to use. In most cases, I analyze the data after the event: I don't need diverse metrics displayed during the ride. The numbers are produced by the Vector, not the head unit, since they involve samples taken at substantially higher than the 1-per-second rate of the head unit. So updating the head unit would be simply a matter of accepting the associated data field types. As far as I'm concerned, they don't even need to be displayable. I just want them to be recorded.

Rainmaker made the argument that the Edge 500 is 5 years old now and you can't expect Garmin to continue to support 5-year-old hardware. But this is misleading: the unit isn't some deprecated unit which has been displaced by a superior product in the same space. But they don't, and the Edge 500 is still manufactured and is still popular. If you walk into a bike shop and see it for sale today, that it's 5 years old is trivia. As far as you're concerned it's a current product.

The key point here is that this isn't about increasing the value of an Edge 500, which already has well-established value. Rather this is about increasing the value of the Vector, a much newer unit, so that it works fully with the Edge 500.

So I wish Garmin would fix this unfortunate decision: after spending $1500 on a Vector, customers committed to the 500 shouldn't miss out on important functionality which differentiates the Vector from cheaper alternatives.

Saturday, December 27, 2014

modern bar design: the Enve SES Aero

Caley Fretz is one of my favorite cycling reviewers. He now works for VeloNews, where he wrote this review on the new Enve SES bar:

The shape of the SES is a reflection of the way that positioning has changed in recent years — as bars have dropped relative to the saddle, and our understanding of aerodynamics has improved, it has become clear that the lowest drag is often found with hands on the hoods, elbows bent at 90 degrees, chin to the stem.

The SES design allows for a narrow, aerodynamic hood position — 37cm on my test bar — while retaining a wider drop area, 42cm. Narrow when you want it, wide when you need it.

Here's the Enve:

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I love new ideas!

In completely separate news, VeloPress has recently published Goggles and Dust, a book based on the remarkable photos which are part of the Horton Collection:

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Tuesday, December 23, 2014

moving target: restoration of Skyline Boulevard Bridge

Back in the day, back in the early days of recorded time (i.e. since I got a Garmin 500 and signed up for Strava), we used to ride an SF2G Skyline route which didn't descend Crystal Springs to Polhemus bus instead remained on Skyline Boulevard, crossed a bridge at the dam under the 280 Flyover, and then climbed back to Highway 92.   The memories of that nearly forgotten time must be reconstructed from the yellowing pages of the Strava archives lest they be forgotten forever.

Note the rather direct route near Crystal Springs. Now compare and contrast:

You can see the difference near the "Belmont" label: a left, right, right, left while the earlier route takes a relatively straight line.

The alternate route involves a descent of Crystal Springs Road, a right turn onto Polhemus, a long climb there to where it turns into Ralston past the Highway 92 interchange, then passing through a parking lot to descend back to Cañada Road via a twisting bike-pedestrian path which ends with a stiff but short climb to cross over Highway 280. The whole thing adds around 15 minutes for a fast southbound rider.

Why? The bridge on Skyline Boulevard was assigned to be updated for seismic compliance. The promised finish: an incomprehensibly long 2.5 years, until the spring of 2013. Wow. But somehow we'd survive.

It's now fall 2014, and the projected completion date: spring 2017, 2.4 years. So they've made 0.1 years of progress in the past 4 years, an efficiency of 2.5%. Building the entire Grand Coulee Dam took 9 years, so they're looking now at a renovation project on a small dam and bridge which will take most of the time to build one of the great engineering feats of our history, close to double the four years it took to build the Golden Gate Bridge.

In response, some riders have taken to occasionally riding the Highway 280 shoulder along the "flyover", the connecting Golf Course Road and Belmont Road. The 280 shoulder is already legal in two sections further north thanks to the hard work of bike advocates in the 1970's, as at the time it was argued that there was no timely alternative for north-south travel. This is the condition today: the Polhemus detour adds a substantial time and effort to the ride.

Personally I've not objected too strongly -- the goal in riding to work via the hillier and longer Skyline route instead of the flatter and faster Bayway route is for fitness. But for some, in particular those working closer to the mountains than the bay on the peninsula, Skyline is faster and riders have a stronger motivation for reduced transit times. But given the history in delays for the project it makes sense to allow cyclists to use this section of 280. The primary issue is simply one of acrophobia, since the "flyover" is elevated well above ground level. But if a car hits you hard enough to knock you off the edge you were probably a goner anyway.

The following is a history of the projections for the completion of the seismic upgrade project, which was forwarded to the SF2G mailing list. I'm not sure who the original author is, but it's good stuff. I'd love to know why the project is apparently progressing so much slower than originally projected.


Here's there's original dates still on this blog.

 The demolition is on schedule for completion by February 2011, with the replacement bridge opening in 2013.

The internet archive has May 4 2011:
Skyline Boulevard between Crystal Springs Road and Bunker Hill Drive is closed as of Friday October 29, 2010, and is expected to be reopened in the Summer of 2013.  Click the road detour map for detour information.

On May 12 2012
Skyline Boulevard between Crystal Springs Road and Bunker Hill Drive is closed as of Friday October 29, 2010, and is expected to be reopened in the Fall of 2014.  Click the road detour map for detour information.

Then in July 2012
Skyline Boulevard between Crystal Springs Road and Bunker Hill Drive is closed as of Friday October 29, 2010, through Fall of 2014.

As a result of the San Francisco Public Utilities Commission's (SFPUC's) Crystal Springs/San Andreas Water Transmission System Upgrade (CSSA) project, construction of the County's new Crystal Springs Dam Bridge project will be delayed until approximately September 2013.

October 2013:
Skyline Boulevard between Crystal Springs Road and Bunker Hill Drive is closed as of Friday October 29, 2010, through Spring of 2015.

As a result of the San Francisco Public Utilities Commission's (SFPUC's) Crystal Springs/San Andreas Water Transmission System Upgrade (CSSA) project, construction of the County's new Crystal Springs Dam Bridge project will be delayed until approximately Spring 2014.  To facilitate construction of the SFPUC's CSSA project, the scenic vista point parking area located south of the Sawyer Camp Trail terminus will be occupied by SFPUC's contractor for material/equipment staging until approximately Spring 2014.  Subsequently, construction for the County's Crystal Springs Dam Bridge replacement project is expected to take about 1 year to complete with an anticipated reopening of Skyline Boulevard (Highway 35) between Crystal Springs Road and Bunker Hill Drive in the Spring of 2015.


So let's see progress:
dateestimated time to completion
04 May 201127 months
12 May 201230 months
July 201228 months
Oct 201319 months
Dec 201429 months

So in the past 3 years of work, the projected time to completion has actually increased 2 months, from 27 to 29. That's not moving forwards, but rather backwards. Is this a new dose of honesty and we'll all be riding over the bridge by summer solstice 2017? I hardly think so. But the project has to be finished at some point, assuming there's not an earthquake during the interval which sends it all crashing down.

Friday, December 12, 2014

2014 Low-Key Hillclimbs: Mount Hamilton report

Thanksgiving marked the ninth and final climb in the 2014 Low-Key Hillclimbs. And as it has been every year we've done the series, Thanksgiving marked the longest "single" climb we do, Mount Hamilton Road.

Single climb is in quotes because John Summerson has asserted that Hamilton isn't a single climb, but rather three. And indeed the descents are considerable. But with a net elevation difference of 1161 meters and total climbing of 1340 meters, that's an "altitude efficiency" of 86.6%, so it is considerably more up than down. A series of three equal climbs separated by two descents to the original elevation would be an efficiency of only 33.3%.

I began my day in San Jose, having stayed with a friend, and a weather check showed the temperature in the city was 44F but at the summit, at 7 am or so, it was already 62F. So it was unusually warm, a common trend this year. Despite this I wore a wool baselayer in addition to knee warmers, shorts, and a short-sleeve jersey. With a light jacket this was sufficient for the warming morning air at base elevation. Before the start I put the light jacket into Kevin Winterfield's rental car, which was doing support duty,

I gave my speech advising riders to not start further up than they should: I 'd assigned group numbers from 1 to 5 to riders for whom I had availanle scores to do so, with 1 being they should line up near the front, 5 near the back. There's a perceived advantage in starting near the front, but if slower riders start too far up it creates passing situations which result in crash risks. So it's way better if people start in the approximate finish order. It's hardly appropriate for me to call for this then step right up to the front of the pack myself, but I tend to overcompensate a bit, and I was starting back with group 2 people which was not the best place for my goal of avoiding the start line snafus which caused me to be delayed last year when a rider had trouble clipping in in front of me and caused me to burn a match to cross a gap.

But while my starting position could easily have been trouble, the pace at the start was unusually sedate. I had no problem following wheels, and was able to take advantage to move ahead when space opened up toward the left of the right lane to which we were dutifully confining ourselves. This proved a good move, because not long after moving up I looked back and our group had separated itself.

But up the road, three had already taken advantage of the relaxed start: Chris Evans and series leader Stafano Profumo of Squadra SF, along with Hanns Detlefsen of Sistes and Misters had established a considerable gap. Back in my group, favorites Ryan Sherlock and Adrien Costa along with dark horse Brian Lucido sort of neutralized each other, none wanting to drag the others up this first of three climbs where "keeping the powder dry" is the prevailing strategy. That strategy was not held back in the last decade, or the decade prior by Tracy Colwell or Tim Clark, each of whom used their dominent strength to shed the field from the front. But this was going to be far more tactical.

By Grant Ranch I was still feeling fine. The lead three had a 3-minute gap at this point, and extended it further on the close-to-two-mile descent before the start of climb #2. The descent has in the past caused me problems, since with a tendency for gravel to accumulate in the corners exercising too much caution is always a temptation. But I had no issue keeping up with the riders around me. Part of this was due to using my carbon Ritchey MT-32 wheel with Veloflex Carbon road tire rather than the Edge 100 rim with Vittoria Crono time trial tire I more often use on climbs. This wasn't a tactical choice: the Crono is flat and my attempt to order a replacment in time failed due to Sports Basement getting the wrong tire.

But the front wheel, with better aerodynamics, traction, and braking even if it had slightly inferior rolling resistance and a significant amount of extra mass, was probably the best choice today, and I was able to descend confidently.

Different years different riders have different tactics and it is obvious that one of the tactics this year was to shred the lead group on climb 2, because as soon as we hit the end of the descent, I found myself too deep in the red for the 2848 vertical feet still to come. I had two options: stay with the group as long as possible and then hope to struggle the rest of the way, or throttle back immediately and try to ride a more sustainable pace. I chose the latter option. I thus found myself with Shahram Moatazedi and Oleksiy Mishchenko. Shahram was clearly strong, and I didn't see any obvious signs Oleksiy wasn't also ready to keep a good pace. Shahram pulled at first, then Oleksiy came through, then I took my turn.

There's always an initial enthusiasm at the bottom of a climb, and this was no exception. A later review of my data, applying a power-speed model, showed even though we let the leaders go this was still what for me is an unsustainable pace. But I still felt okay, and as I moved to the front I thought maybe I'd succed in dropping someone. But no luck: they stayed on my wheel. So I put in a decent time at the front then pulled off to let Shahram have another shift at the front.

At about this time I saw the unmistable figure of Daryl Spano up the road. He's tried to stay with the leaders longer. clearly, but had reached the same conclusion I had eventually. Daryl and I are often closely matched, so if I can ride with or faster than Daryl, I know I'm doing well.

With Daryl as a rabbit, we closed the gap, and Daryl joined our group. I'm not sure where we lost Oleksiy, but it was somewhere along this second climb. That left the three of us. I think I took one more pull along the way, but the climb gains only 788 vertical feet in its 3.2 miles, so we were to the top relatively quickly by Hamilton standards.

The second descent with our small group wasn't an issue, and we were soon at the bridge which marks the start of climb #3. This bridge offers a clear view of the summit observatory, which while it appears tantilizingly close, is still 6.6 miles and 2060 vertical feet away. This final climb is longer than all but 16 of the 53 climbs for which I have stats from Low-Key history, so it's a challenging climb by Low-Key standards all by itself. It demands respect. Optimism due to the view must be tempered.

The entry to the bridge is a corner where Nils Takkenen crashed three years ago: it's tempting to rail it but it can take you down. I apexed it a bit more than I probably needed to, sticking with my two companions.

And then we were onto the climb. I tried to follow Shahram but he went out a bit too fast for what I had left in the tank and I let a gap open. I was able to limit the damage, though, and the gap stabilized. But try as I could I couldn't close it.

I wasn't the only one in difficulty, Daryl was dropped behind me. My eyes were ahead, not behind, though: doing my best to keep a tempo which gave me a chance to close that gap to Shahram.

But I could not. He wasn't gaining on my, but I wasn't gaining on him. We were in stasis.

There's a sweeping right turn where going in you can see riders ahead of you above, then coming out you can see chasing riders below. Going in I saw Shahram, of course, as he'd been hovering ahead of, but I didn't see anyone immediately ahead of him (Brian Schuster was next, and he had a big gap). However, coming out I saw Daryl Spano chasing from behind, not much more behind me than I was behind Shahram. Well, I already knew Daryl never gives up... so this was added motivation: pulled from ahead, pushed from behind.

image
finishing (Bill Bushnell photo)

But so it remained. Daryl never caught me, but then I never caught Shahram. I hoped, I willed him to crack, just a little. All I needed was a little. But he held his gap to the final rise to the summit. Once I turned there, my last chance to catch him was just ahead, so I spun it up and suppressed the pain and gave everything I had left. Indeed, in those final few hundred meters I closed on him but not enough: he crossed the line 5 seconds ahead. So close. Could I have gone a bit faster a bit earlier? That's hard to say: cycling is such a mental game. But I was wasted at the finish, and I think the better rider won that little battle.

Afterwards I looked more closely at the data, applyin a bike power-speed model to my Garmin numbers. Here's the result, where I assume a coefficient of rolling resistance of 0.4%, a CDA of 0.32 meters2, a drivetrain efficiency of 97%. Note the CDA is a compromise between drafting on the first climb and part of the second, being in a tuck on the descents, and less aerodynamic solo riding on the third climb. The other parameters are estimates. I further estimated my bike mass was 6 kg, my body mass 57 kg, and my clothing and water bottle 2 kg. Here's that result, using 20 second smoothing:

image
calculated watts versus distance

For reference, here's the altitude versus distance:

image
altitude profile

On the first climb, which felt so easy, the power is sustained at around 260 watts. In reality is was likely lower, perhaps 250 watts, due to the benefit of drafting (I can emulate this by reducing CDA, for example to 0.28 meters2).

On the descent, power was low, as I was coasting in draft, even though the model shows relatively high numbers. This is because I was in a tuck and so CDA was lower than modeled, and additionally because I was in rider draft much of the time, a substantial benefit because larger riders ahead of me have higher terminal velocities.

At the second climb, power was unsustainable high. This is where the selection was made in our group, and although I gave up hope of following the leaders early, I was still putting in a big effort here. That paid off by putting me in a compatible small group, which gave me draft on much of the relatively short, gradual second climb.

On the third climb is where things unraveled on me, though. Although I was following Shahram, and the gap to him remained stable, it is clear we were both running out of gas here. Had my endurance been better I could have closed the gap simply by sustaining the power I'd maintained earlier in the climb. To some degree I was perhaps paying the price for the relatively hard pace at the bottom of the second climb, but in the end the real solution was more fitness. Practice makes perfect and with my present work situation my ability to train on climbs during the week is extremely limited, while access to climbs on weekends from San Francisco is also tough (it's a decently long ride just getting in and out of the city, and I've not had the time to do that as much as I used to). In any case, I did the best I could.

At the end you can see the little blip at the end where I pushed the pace on the final rise. The model shows this was relatively unimpressive. That's a good thing, because if I'm too strong on the final bit, that means I didn't ride hard enough leading into it. I'd given pretty much everything I had.

In the end, no complaints. I did what I could, and my overall standing in the Low-Key Hillclimbs ended up being tenth, which is very respectable.

Big changes are happening in my work life, and it remains to be seen what my plans are for running and cycling in 2015...

Thursday, December 11, 2014

VeloViewer mileage summary and Strava OLH times

This blog has been neglected due to other activities, in particular the final weeks of the 2014 Low-Key Hillclimbs, but additionally due to a transition in my work life. I've been at my present job starting October 2010 through today, but that will be changing the beginning of 2015.

This period roughly coincides with my time on Strave. For aggregated those data, VeloViewer is a great tool. They just implemented an annual £10 fee to access full data, and it's paid off in this one plot.

2014 started off very mediocrely. I focused on trail running until April, and that hurt my total mileage, but it ended with a very successful debut at the 50 km distance, the Woodside Ramble. Then there was a downtime associated with preparing for and actually moving to a new place in San Francisco. Starting in September, however, I recovered, with 4 very solid weeks end-of-September-to-start-of-October in Switzerland. After that I did fairly well, participating in Low-Key Hillclimbs, and getting in a decent number of SF2G rides. You can see the slope has been fairly good, even if total mileage is well below the level of 2012.

Strava just recently introduced a segment time plot, which is really nice. Here's mine for the "Low-Key Old La Honda" segment. Old La Honda times, mostly riding the Ritchey Breakaway on the Wednesday Noon Ride, have been quite stable this year and last, quite a bit slower than 2011, but what can you do... 2010 was a slow year since I wasn't able to train as much as I'd like, with the work transition.

I never felt at my best on Old La Honda this year. But since my present work plans take me to Berkeley, I don't know when I'll have an opportunity to do the Nooner again. Maybe I need to plan a weekend trip via Caltrain to give it a go when I have some cycling fitness next.