I’m a pro mountain biker, my life revolves around training and good beer. I trained for seven years simply using heart rate data. While that was a useful metric and helped me set some training parameters, it was often frustrating. Heart rate can be affected by many different variables and I found that my heart rate was especially, well, frustrating. It would drop after a couple days of hard effort. Depressed heart rate is normal, but it was hard to gauge how hard I was actually going. Was I recovered enough to keep training, or should I go home? I wanted to try training with power because wattage numbers don’t lie, but it was not affordable for me with every spare penny going to paying race entries and travel.
The first powermeter I tried was a Cyclops Mountain Bike Powertap, and at the time was the most affordable option on the market. The powermeter is placed in a sturdy rear hub. It worked great for training and I didn’t have durability issues despite riding in every condition imaginable. The limiting factor was the weight. A Powertap MTB wheel is extremely heavy and I would certainly not race with it.
For those of you not familiar with power, it’s a unit of energy measured per unit time in watts or Joules/second. It tells you how hard you are pushing on the pedals and in my opinion is currently the most useful training metric out there. I also like it because if I’m riding with friends thinking, “Oooooof, this feels too hard,” I look at my power output. It is a good check to say, “Oh yeah, I AM going too hard for my goals today.” Knowing what your power numbers mean and how to train with those numbers is an adventure on its own, but you get an idea of where you normally perform. There are tons of books and coaching programs that go into the nitty gritty. Daniel Matheny, an accomplished pro mountain biker and coach for Carmichael Training Systems says, “Power is an objective measure. It’s like knowing your pace while running or the amount of weight you can lift in the gym. Other metrics like heart rate and rating of perceived effort (RPE) are subjective and ultimately can change based on other variables like heat and hydration.” Power also gives you a very good idea of calories burned because it goes off the power number and calculate kilojoules. Most calorie estimates are based on a less precise algorithm taking BMI and heart rate into account. Another great thing about power is that you can see concrete proof of improvement; something that keeps me motivated to keep training hard.
So I had this Powertap that I liked, but it was heavy and wasn’t helping me much on race day. There in lied my paradox. I loved training with power, but I wanted something light enough to race with. Having a powermeter on race day is immensely helpful in monitoring my effort with competitive adrenaline pumping through my veins. SRM was the only powermeter I had heard of, and it was far beyond my price range with a tag of over $2,000.
That’s when a new player entered the arena with their own power play. I discovered Stages Power meter at Sea Otter a couple years ago. I learned that they were a Boulder based company, and proud to be from Colorado as their logo creatively reveals. I also saw a very handsome and attainable pricetag of $700.00. The last piece of the puzzle – was it light enough for racing? You betcha!
I visited Stages in Boulder to learn more. The power meter is installed on the inside of an alloy left crankarm. Carbon cranks are not available because the meter works with multiple strain gauges and carbon is too flexy. My electrical engineering background perked up when I got to see the design process, the extensive testing, and the algorithm on how to calculate power based on just the left crank. I know my left leg is weaker than my right, so would my numbers be skewed? How about temperature variability with the alloy? Compared to a TacX trainer (a trainer that measures power) and my Powertap, my numbers are all within 5 percent.
I was very happy with my purchase. I used my Stages Power meter at the my record setting win at the Breck 100 this summer in very rainy conditions, exposed it to the rocky, technical Canadian terrain at the Trans Rockies, and tested its limits through extreme temperatures, heavy moisture, and gritty conditions of Mongolia Bike Challenge. The CR2032 battery is easy to change, but I haven’t had to worry about it yet. It’s also compatible with my Iphone and my Garmin with multiple upload options. Stages makes a crank for many different drivetrains for both road and mountain. Coming from someone who does not enjoy working on bikes, you can move the crank arm from one bike to another quickly and with ease.
After a bit of a lazy off-season, I’m not as pleased with my power numbers compared to the summer. While my Stages showed me how fast I was getting over the summer, it also is showing me how much fitness I have lost! It’s time to start building and watch those numbers grow.