Friday, January 04, 2008

Designing a Bike Racer

Many years ago, as a young Operations Research Analyst, I worked on a study with the charter of determining the best characteristics of a next-generation fighter aircraft. The F-15 was getting old and Pentagon big-wigs were getting worried about new threats. Our job was to sort through the myriad design choices and make recommendations for an F-15 replacement.

This kind of DoD study group typically has a variety of players, including: the "Gray Beards" who are basically old guys who've been around a long time and like to pontificate; procurement bureaucrats whose job it is to wisely spend tax-payers money; US Air Force folks who ultimately fly the aircraft; and analysts who do all the work. You know those kids in class who would draw elaborate air battles on their paper with fighters and missiles and guns and explosions and stuff? Well, those kids grow up to be analysts and then get paid to do that same thing, only with computer simulations and math equations. That was my job back then.

Only it was really complicated, and you can't have it all. "Faster, better, cheaper... pick two" is a classic saying attributed to some Dilbert NASA engineer who was probably telling his pointy-haired boss that you have to make choices and must make sacrifices in some dimension or another.

With respect to a fighter aircraft, you have a number of critical dimensions to think about. They include the stealthiness of the aircraft, its cruise speed, its unrefueled endurance, the weapon load it carries, its maneuverability, and the performance of its sensors. These dimensions are illustrated on the "spider plot" below...

    Analysts sometimes use these kinds of conceptual plots when considering a lot of dimensions (i.e., more than can fit on a standard 2-D or 3-D graph). Each axis represents some characteristic of a fighter aircraft, and further out the axis represents better capability. The plot above has an inner dashed-line contour drawn notionally to represent an F-15. The outer-most dashed-line contour represents the absolute maximum that could be achieved in each dimension. That maximum could be a limit of physics, cost, or some other practical constraint.

    In reality, you cannot achieve the maximum in every dimension. You have to make choices. Two such choices are drawn on the plot above. The Blue contour represents a stealthy, fast-cruising, long-endurance aircraft. The Purple represents a very maneuverable, highly-armed aircraft. Which is better?

    Well, without getting into a ton of nitty gritty detail, let's just say... it depends. What is the mission? Where is the threat? Which tactics will you use? on and on...

    The analyst might say, "Build a really stealthy fighter so you can win before the enemy even sees you!"

    ...to which an USAF pilot might respond, "What if I get into a dogfight ...I need maneuverability and weapons!"

    "But I calculate that you'll get three shoot-look-shoot opportunities before he even detects you!!", cries the analyst.

    "Dammit, air-combat is not a math problem you snot-nosed punk!!!" yells the pilot.


    OK, calm down. The exchange above is purely fictional and has nothing at all to do with bike racing ...or does it?

    Let's start with something relatively simple and non-controversial. The plot to the right is a notional representation of Andy Coggan's Power Profiling. I've altered the presentation slightly to make some points. First, the plot illustrates maximum power output (in W/kg) for a spectrum of durations (5 seconds, 1 minute, 5 minutes, and 1 hour). The black line is meant to represent an "average" rider. Now, you're free to define that any way you wish, but to me it's most meaningful if it represents a typical rider in the same circumstances as yourself (or myself). In other words, for me, I'd assume an average Masters-age rider who can put in 15 hours a week of training and who has many years of racing experience.

    Two notional riders are sketched onto the power-profile graph, a typical crit sprinter (Blue) and a typical roadie/rolleur (Red). This simple example should agree with everyone's own experience. Surely you know riders who are better sprinters than you, but who don't climb or tt at your level. Alternatively, maybe you know a better tt'er or climber who you could beat in a straight-up sprint.

    Which is better? The sprinter or the rolleur? The rolleur tries to drop the sprinter so he doesn't need to fight in the endgame. The sprinter tries to survive to the endgame to use his weapon. See the analogy?

    Of course it's really much more complicated and multi-dimensional. As K-Dub famously once said, "Bike racing ain't a math problem."

    Here's my thought on a 6-D spider plot for a bike racer:

    Let me define what I mean by each axis:

    • Aerobic Power: Just what you think it is, namely, maximum power output over durations of five minutes or longer. For example, the Glendora Mtn TT in the San Dimas Stage Race.
    • Anaerobic Power: Maximum output for shorter durations, say, 30 seconds to a couple minutes. This is the brutally hard surge or attack that almost causes you to black out. Personally, I think of Daniel Ramsey's last lap attack up the hill in the Conquer the Canyons RR. It was wickedly hard, let me tell you.
    • Sprint: Everyone knows what a sprint is, but I mean to include more than 5-10 sec. power here. I also mean those intangibles like positioning, bravery, intelligence, and cunning.
    • "Short-term" Recovery: a measure of how able you are to do repeated short-but-very-hard efforts. This is like covering a whole flurry of attacks or going up the hill at Nevada City. Way over threshold, back under, way over, back under, repeat...
    • "Long-term" Recovery: By this I mean day-to-day and week-to-week. At one level, it affects how you will do in a hard stage race. At another level, it determines how hard you can train.
    • Endurance: As in "suffering", like when it's 90 degrees out and you're trying to hold onto a wheel in the 3rd hour of a race and you're cramping.


    Just like the spider plot for the fighter aircraft, this one has a few conceptual contours. The outer dashed-line ring denotes the maximum capability you could possibly achieve in each dimension. Let me be clear, by that I mean the level you could achieve by focusing all your training exclusively on maximizing that one dimension. Therefore, almost by definition, it would be impossible for a rider to reach the outer contour in every dimension. The inner contour alternatively, represents an arbitrary level of "weak" in each dimension, whereas the middle dashed line is your "average" rider.

    The red contour on the plot is my judgement of my own capabilities in recent years. Better than average W/kg and (sufferer) endurance, average in anaerobic power, less than average elsewhere. I know this to be correct without any quantitative information. Racing against the same people every weekend for years tells you all you need to know about where you're strong and where you're weak. Do you make the front split? Do you win the sprints? Do you fade and cramp at the 2-hour point? How many matches can you burn covering attacks? Do you get relatively stronger or weaker on the 5th day of a stage race?

    My main purpose in talking about this subject is that a bike racer has some choice in his/her development (or design, if you will). Many of us default to doing the same kinds of rides year-in and year-out, and we lose sight of the control we have. So few racers do dedicated sprint training, for example, yet most races come down to a sprint of some sort. Similarly, not many people do the gut-busting 1-2 minute intervals that train your body to endure the repeated anaerobic efforts you face in some races.

    To be sure, the dimensions I drew in the spider plot above are not totally uncorrelated. Improving one can help in the others. For example, if you max out your aerobic power, it will help in most of the other dimensions. But there is a cost. You cannot reach your maximum potential in every dimension. For example, if you want to be the very best sprinter you possibly can, then you will sacrifice some of your endurance and aerobic power.

    Let's talk about two local examples. First, Adam Duvendeck has become one of the best short-distance track riders in the US, but it didn't come easy. Rather, it's taken him 10 years of hard training to reach that level. Very dedicated and focused training, emphasizing technique, strength, and explosive power. He could blow away most anybody in a kilo or straight-up sprint, yet he'd probably get dropped in a Cat 3 road race. He made his choice about where to focus.

    Chris Walker, on the other hand, has dedicated the last 20 years of his life to maximizing his aerobic power, endurance, and long-term recovery. Really, I doubt there's any room for improvement in those dimensions. His fat-burning metabolism is truly maximized. He won the Elite National RR championships when over 40 years old. Yet, half the field of a SoCal Cat 3 crit could probably beat him in a straight-up sprint. He made his choice too.

    Now, you might be thinking that Chris is a natural roadie, and Adam is a natural trackie. You'd be wrong. I've watched the evolution of each of those guys. Both are where they are today due almost solely to really hard and focused work. Chris has designed himself to be a stealthy, long-endurance, cruising fighter. Adam has turned himself into a top-gun dogfighter.

    So, my challenge to you is: make your own bike-racer spider plot, and put yourself onto it. If you don't like the dimensions I chose, pick your own. After you've done that, think hard about whether or not your strengths and weaknesses really match what you think is the most desirable design for the kind of bike racer you want to be. If your strengths perfectly match your design, then great... keep doing whatever it is you're doing. Otherwise, think hard about your training choices and consider making some changes. (Note: I am talking to myself here!)

    Sincerely,
    Aspiring Gray Beard

    12 comments:

    TnA said...

    F15, sheesh, that's SOOO old school. I just want to be an F35 Lightning II:

    http://en.wikipedia.org/wiki/F-35_Lightning_II

    That's all...I think I might have to quit my job though to make that happen ;-)

    Marco Fanelli said...

    TnA- Perhaps I wasn't clear... the study was to determine the fighter that should replace the F-15. That fighter became the F-22. (BTW, won by LM in a brutal competition with Northrop.) The JSF (F-35) is also a very capable airplane, but designed for a different mission than either the F-22 or the F-15.

    TnA said...

    OK...I still want to be an F35. The only thing better than it in air-to-air is the F22, and it's got it beat in every other axis.

    Sounds like a good "fighter" for me "emulate" :-)

    Gianni said...

    Excellent topic and one that's on my mind as well.

    As much as I like the long miles, I think the very short events suit me better.
    As hard as I trained my endurance the last few years, I could only push my spider graph so far to the upper right.

    Nice analogy.
    J

    Anonymous said...

    Dance Dance Revolution uses spider graphs too.

    Jason said...

    Holy sh...! Glad to see your starting off the new year by breaking out of the one dimensional bike racer mentality.

    Actually very interesting stuff. It would be interesting to take a huge sprinter and spend 15 years making him into a climber and see how far he could get.

    I thought I was a climber to some degree until Everest Challenge. Now I'm not a climber or a sprinter.

    TnA said...

    BTW, I'm thinking you may be somewhat downplaying the relative "help" that increasing your "aerobic power" (as you call it) adds to basically every one of the other categories. To borrow an economics quote, "A rising tide lifts all boats."

    Pretty much any effort longer than 20s or so has a pretty significant aerobic content. That basically means that most of the axes of the spider plot are somewhat tied to that one leg. To quote Dr. C, "It's an aerobic sport, dammit!" :-)

    Just my 2 pesos...

    Marco Fanelli said...

    Gianni- Aren't you a good tt'er and cx rider? That seems to me like a pretty good base to push outward from!

    Anony- DDR is the best!!! ...so I'm in good company using a spider-plot, eh!?!

    Jason- For whatever reason, Everest was an anomaly for you (in my opinion). You are still a bike racer, both a climber and a sprinter.

    TnA- I am not downplaying anything, and again I think you are missing my point (which is too lengthy to expand upon here in the comment box with dinner waiting).

    Aram Dellalian said...

    Hm. I've always said "i'd sacrifice some of my sprint for some extra juice on the climbs.." and that's right in line with your proposed suggestion of focusing on weaknesses. But I don't subscribe to what you're saying.

    Take C-Walk: Go back two decades, and try to turn him into a sprint machine. Sure, he'd be better than he is now, but there is a terminal limitation just based on a rider's physical (fiber orientation, tissue size, etc) build.

    For me, all bike racing comes down to threshold power in relation to your weight. Improve that, be a better bike racer.

    Marco Fanelli said...

    Aram (and TnA)- I'll respond in another post in a few minutes.

    jAndy donka-donk said...

    that was a really cool post.... all up to the point where you started talking about bike racing....

    you never leave your wingman... I meant "tell us some stories dad, and leave out all that bike racing crap"


    that first story was just getting cool.....

    Marco Fanelli said...

    Thanks Junk-a-Dunk! and the comment was just getting funny.....