Wednesday, October 19, 2011

Cyclocross Course Design, Technical skills, Fitness

Groups of riders usually signal un-technical riding.
Photo Credit: Lyne Lamoureux
Following some recent races both at the national and local level, some have been asking, commenting, and wondering how Cyclocross (CX) course design plays into the outcome of the race.  This proves a very interesting topic and something that could be debated indefinitely.  But first let's talk about some things we do know regarding CX course design and conditions.

First, we know that there are virtually no statistics kept in cycling.  At least not nearly detailed, or accurate enough to warrant a color man in the commentary booth.  The next time you watch a major sport on TV, note how many statistics you are bombarded with, "this team is 3 of 8 on 3rd and long today."  Or, more vague, "this quarterback has a tendency to look to the left first, then throw right in the red zone."  Even, "this team is 19-1 when leading in the 4th quarter."  Cycling simply does not have those type of statistics available.  Instead they rely on commentators entertaining the spectators with stories or anecdotal evidence.  No one really knows what Sven Nys' win ratio is in mud, when he leads by 3sec with 1 lap to go. Expect to see more on this in later posts.

Besides the ambiance, the most notable difference between UCI CX courses and the local events most racers attend is course design.  As a whole, UCI courses tend to flow better, are faster and are much more technical at speed while local events tend to be much more compressed and constricted, slowing average speed in the belief that tight courses favor the less fit rider who can handle a bike better.  (Obviously there are reasons for the difference such as constrictions for venue selection between UCI and local events, but that's beyond the realm of this discussion.)  However, lap times for CX races tend to run 7-8 minutes each at the elite level and around 9-10 minutes for the non-elite categories.  This is important because it sets the stage for the conjecture: Tight, overly technical and ultimately slow speed course design, while meant to favor the more technically skilled rider, favors the racers who are more fit.

The theory with the course design is to mitigate the fitness component of race in favor of the technical skills.  The premise of the theory is that because some have better bike handling skills, but not as much fitness, the more turns the better.  And the tighter the turns, the better.  This allows the handlers to show off their skills and gain ground on the more fit, yet less proficient bike drivers. Unfortunately, a different result usually ensues.

Often times, a course designed as stated above will contain many tight turns that force speeds to drop dramatically and often during each lap.  Hairpin 180 degree turns are the best example. Is this technical? Absolutely, but not technical enough to put the favor in the hands of the superb bike handlers.  This is because once a rider has the fitness to reach the terminal velocity of the corner (speed at which physics limits absolute traction and speed of the corner) then the advantage dealt to the bike handlers is eliminated and is shifted back to the more fit, less technical rider.  Why?

Confusing, ain't it?
Because once that velocity is reached and the brakes are applied, everyone is RESTING! If each hairpin 180 takes 7 seconds to negotiate, then that's 7 seconds of total rest, which can seem like an amazing eternity to anyone who has done micro intervals or anaerobic capacity work (imagine getting 7 extra seconds to rest). The net effect is that the fit rider is more fresh, relatively speaking.  The more fresh rider is able to hit the gas, HARD out of every turn for the entire race if they are rested enough, relatively. The repeated, near maximal efforts will always wear more on the less fit riders and result in them eventually being dropped.

So how is the technical rider able to compete?

In order make a CX course that benefits technical ability, course must be set up in a way that allows those who have fantastic handling skills can stay at speed, while those without the skills, must pull the brakes.  But the terminal velocity of the turns must be high enough while the speed is allowed to stay high enough without expending energy while riding a particular section.  (The videos below are a great example of needing more skills to go faster, regardless of fitness)

However, there is one caveat to all this talk about bike handling... cyclo-cross will always be an endurance based sport.  This means that while fitness alone may not be a sufficient quality to succeed in CX, it will always be necessary.  Often times, superb bike handling only accounts for a handful of seconds per 7-8 minute lap and while they can make a difference they should be put in perspective.  An 8 minute lap is 480 seconds.  So, if superb handling allows up to 12 seconds per lap over another rider the net result is a ~2.5% gain which if applied to a 60 minute elite race is just under 90 seconds.  Not much.  You can practice technique for races, but you can not fake fitness.

Time indices 0:55-2:37 and 4:43-5:38, but it's a good video of Jingle CX in Iowa City, IA.