You do, of course.
Or at least, that's what some people would like you to think. You can't pick up a bicycle magazine, or click on a bike industry cheerleading blog without reading about the latest power meter that's "guaranteed" to take your cycling up to a "new level." If you aren't measuring your watts you're just pedaling around, and what's the point of that?
|Crank based, pedal mounted, or hub-based -- power meters come|
in all shapes, sizes, and styles. Why limit yourself to just one?
Maybe they spend so much time watching their performance numbers that they forget to look at the numbers in their credit card statements?
|You can never have too much data.|
Searching around various bike blogs, I've found examples of performance addicts for whom having just one power meter wasn't enough. For something as important as measuring watts, you can't necessarily trust one type of meter to give you the most complete performance picture. You need meters of different types so you can compare the results. Get the numbers from the crank, then compare them with the numbers measured at the hub. Crunch the numbers through a computer program. Add in heart rate and everything else, and guess what? You're still an amateur, but an amateur with a lot less money.
I liked this quote from one of the blogs, Why You Need A Power Meter: "So why should you get a power meter? The short answer is that you simply are more likely to achieve your race goals by training -- and racing-- with a power meter than without. It is the most affective (sic) tool you can get to go faster on a bike."
In fact, that blogger would recommend a power meter over "fast wheels" -- "every time." "When it comes to speed the engine is always the most important part. A power meter will help you develop a bigger one. With sleek wheels you still have a small engine."
Except that for the performance addicts, it's not a question of one or the other. It's both -- or all of the above. It's the $1000 power meter and the $3000 wheels. The $6000(+) bike. It's the heart-rate monitor. The computer programs. The off-season stationary trainer. The dietary supplements. Oh, the humanity.
Ultimately, with all this data -- the obsession with numbers and incrementally miniscule (and meaningless) performance gains -- a bicycle just becomes a really expensive training device, and gets farther and farther away from what makes a bicycle great.
My advice? Forget about watts. Unplug and just enjoy the ride.