Power was the single metric I was looking to improve during the lead-up to La Ruta. I became power savvy by establishing my baseline watts at lactate threshold and VO2 Max during the F.U.E.L. testing we covered in Part II and then had the next six months to train against these numbers to improve fitness and manage nutrition on long rides. Yet I still had just one gap in my arsenal of gear: a power meter for my mountain bike. The Stages Power X9 ($700) is both new and affordable relative to other power meters, so I decided to give it a test run.

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Boulder-based Stages Cycling is the only company that offers mountain bike power meters that won’t break the bank. In fact, few options from other brands are priced at less than $1,000. The X9’s non-drive side crank arm with a housing that’s impenetrably sealed to the elements doesn’t require any additional mounted hardware; it communicates with bike computers, multi-sport watches and smartphones via either ANT+ or Bluetooth; there’s 200 hours of battery life and even active temperature compensation to ensure accurate readouts regardless of clime.

For pseudo-mechanics like myself, the Stages’s simplicity in design is a major relief, especially when it’s compared to other crank-based models that require bottom bracket adapters, magnets and a mounting device near the crank to measure cadence. Magnets mounted under the frame may be fine on the road, but spending all day in the rain forest of Costa Rica is an entirely different beast. I needed something that could handle this uniquely brutal beating and still keep working.

The Stages Power line borrows its power-tracking solution from the smartphone. The same technology that tells your iPhone if it’s upside down or tilted — the accelerometer — measures cadence by tracking the crank position and each rotation while calculating power based on the flex of that arm. This system allows for the Power’s self-contained construction, which in turn makes for its easy installation: simply replace the non-drive crank arm, pair the power meter to a compatible head unit and head out for a ride. I had the crank installed and paired on my SRAM XO Scott Scale Pro within 15 minutes. The hardest part of this installation was determining which IPA to drink while I did it. In fact, the only issue I found with the X9 is its lack of support for carbon cranks. This is a small sacrifice for us who like aesthetically balanced bikes, and if you’re faster than the next guy, no one will notice.

Having power data on display is a constant reminder that you are either way outside of your zone or that you can push a little harder. The latter is always preferred.

My first ride with the Stages X9 power meter was a 5.5-hour aerobic spin through the North Georgia mountains. The goal for the day was to find a sustainable pace without feeling fatigued at the end. There was a steady eight-mile climb right out of the gate, and I took off at normal pace — but when I looked down at my Garmin, my watts were over 250, far higher than my target for the day. I backed off. These insight into little pieces of data made a huge difference: the ride ended up right at my target of 5.5 hours with around 8,000 feet of climbing and watts averaging around 175. That translates into 65-70% of a six-hour race pace.

After four months, dozens of rides and 62- & 100-mile races, the Stages’s data has become an essential training tool and even more important racing tool. When I hear the starter’s gun crack it’s in my nature to drop the hammer and try to keep up with the lead pack, a group of guys who even on a good day I can’t hang with for more than 30-45 minutes. Riding outside of the zones too early can spell disaster around the fourth hour of a six-hour race. Having power data on display is a constant reminder that you are either way outside of your zone or that you can push a little harder. The latter is always preferred.

METHODOLOGY: GP correspondent Dirk Shaw tested the Stages Power meter during the coarse of his training for La Ruta de Los Conquistadores.