Sand Section Lesson

A single corner at my last cyclocross event unwound my entire race. The corner in question featured a slight decline and quite dry sand. Lap after lap I failed to navigate the sand. At the end of the day I guessed that my poor execution in this one corner cost me about 90 seconds over my hour of racing. Those lost seconds have motivated this blog post and hopefully a chance to avoid a similarly large error in the future.

The corner in question required bike handling skills and a real time tactical choice to ride or run. Riding was fastest. Running was slower. Attempting to ride, failing, and resuming on foot was slowest. No measurements were available so I'll share my best estimates of ten seconds to ride, fifteen to run, and thirty if a ride attempt failed. Running affects my heart rate negatively and those downstream affects are included in my time estimates.

There was a large risk and small reward for attempting to ride the sand section. And therefore the question is why, in the moment, I made the risky choice to ride the sand corner seven of seven laps despite my string of failed attempts.

The answer is poor assumptions. First, however, some background information that informed my assumptions.

1. Riding was faster than running.

2. On my first sighting lap I realized the challenge of the sand corner and rode it repeatedly to verify riding was a choice with a high percentage of success.

3. During the race I was watching for evidence that other riders were resorting to running the sand and found none.

4. My bike handling is solid (usually). If my competitors can ride an obstacle likely I can as well.

5. During the race I was tracking the changes in the sand section.

If I look at all these points of information statically it appears running is the better tactical choice. Adding in the dynamic points of changing sand conditions and lack of other runners still pointed to riding the sand. On race day this was the end of my analysis and it cost me dearly.

After stewing on my failure for a week my false assumptions became more clear.

The changing sand conditions were eroding two of my data points. The number of seconds to ride the sand was inching up and the ride success percentage was inching down. I wasn't taking this into account in real time.

My second poor assumption regards the absence of other runners. My failure to see runners does not disprove their existence. I suspect plenty of my competitors were choosing to run. I failed to consider this possibility and subsequently failed to reconsider my ride vs run choice.

My general assumption that good bike handling applies to every patch of sand was too optimistic. This short stretch was not in my wheelhouse.

Bringing it all together I believe I was operating with generally good information and thought processes. These general principles were in play for every challenging section of the course and bringing good results everywhere save the sand section. A few poor assumptions, however, conspired to undermine my real time thinking process.

Going forward I want to close the door on this type of failure. Which is a tough nut to crack. Reasoning through my race day assumptions while executing 400 watt intervals on the bike is not feasible.

I do possess another feedback system. It runs the software in my head that is informed by my race experience. This system is subjectivity. I needed no stopwatch to know after my first failed attempt at riding the sand that my execution was 'bad'. After my second or third failure the switchboard for this system was aglow with red blinking lights.

As I continue to contemplate the sand section failure I hope to update my decision system by adding subjectivity as a reality check. When I am riding well I plan to allow data and assumptions to run the tactical decision show. When the primary system leads to a subjectively 'bad' decision I need to be more open to quickly hitting the reset button.

The Cross Revolution series takes us next to Arlington where I'll try to update my real time decision making. Expect me to write about it soon.