The Power System Training Equation
Power meters are one of those things that make you kind of wonder how you ever got along without one. It’s among the major sets of data every cyclist needs: Speed. Heat-rate. Cadence…and Power. In some ways, power is the most useful of all for your training, which is pretty much why every serious rider has one these days. Before you make the investment, though, there are some important decisions to be made.
There are four basic parts to the whole power training system equation: 1) Setting up your bike for power; 2) Choosing the right power meter; 3) Pairing the power meter to a device; and 4) Using the power meter for training
First, what kind of bike do you have? I know. It shouldn’t matter, right? But it does. Some systems work better for different bikes and some simply won’t work with your current setup. You may also be weighing getting a new bike. Power meters aren’t cheap (but they’re also not crazy expensive as in the past). Some people choose to put a meter only on the bike they’re going to do most of their training or racing. If you’re not sure about what power system works best for your particular bike, ask your friendly local bike shop…um, preferably us at Cronometro!
The next consideration relates to crank arms and cranksets. Chances are, you are going to be replacing one or the other, so it might be a good time to make sure you’re happy with what you’ve got. Are you thinking of switching to a longer or shorter crank arm? Are you thinking about buying new pedals?
If you’re wondering about making a change, this is the time to schedule a fit or re-fit with Colin. Why? * Because you’ll need to find the optimal length for your pedaling style, and you will need to make adjustments in seat height and perhaps handlebar position.
If you’re thinking about upgrading your crankset or drivetrain, this is also the time to do it. You might not want your nice new shiny power meter system glued on to your battered and beaten drivetrain that’s 5 years old. It’s up to you, but you might want to think about also boosting your power numbers at the same time that you’re starting to measure them!
* It is almost always our policy at Cronometro to think “fit first.” Even the smallest changes in your set-up will affect your position on the bike. If you make sure you’ve got optimal position before you make the change, then you won’t risk affecting your performance on the bike, or worse, causing injury! Read more here.
So, now you need to decide what kind of power meter you want. We recommend two at Cronometro. Stages and Powertap. The quality is comparable for both systems. You will get highly accurate readings from both systems. The difference, really, is cost and amount of information being measured.
The Stages power meter system is the cheaper alternative. It’s a fairly brilliant little system that is attached to your left crank arm. It measures the pressure you apply to the pedal and sends your power data (plus cadence) to your device. It measures your power output by virtue of what work your left leg is doing on the pedals. When you buy the Stages power meter, you purchase the crank arm to go along with your crankset (Shimano, Sram, etc.). Again, if you’re thinking about replacing your entire crankset or buying new pedals, this is a good time to do it.
Powertap [is the alternative with more features and more complete data. The drawback to the Stages alternative is that it just measures your left leg output. Some cyclists need to know both numbers, especially if they’re concerned about having equal power distributed between both legs. The Powertap gives you that option. The two best Powertap options come either on a crank or in the pedals themselves. If you’re thinking about replacing either one of these anyway, then Powertap might be the better option for you. (You can also put the Powertap on your wheel hub, too, but you then lose the right/left leg dual data.)
It matters what particular device you use, whether Garmin, Cateye, Joule GPS+, Wahoo…especially in terms of how old the device is. While power meters have been around for awhile now, they may not play nicely with older models. Your current one may work fine, but again, it might be good to first ask that local bike shop (we recommend one called Cronometro).
Your power meter and the devices are paired by ant + . Once synced, you can calibrate the power meter for accuracy on your device. From there, there is a whole universe of data to be gleaned. The latest Garmin models do an especially good job of crunching power data numbers from your power meter. You can set up your device to get average power for a ride or an interval set. Power numbers tend to move around a lot, but you can get a more even readout by getting a 3s average or a 30s average in real-time as you ride. If you have a Powertap you can get the power numbers for both legs. You can get data on right/left balance, pedal smoothness, torque effectiveness, etc.
From there, it is a matter of choosing what power data sets you want displayed on your device. You can choose to have the power averaged as you ride, or keep track of the power you are using on a particular interval effort. Most devices allow you to configure your data for a particular riding activity. So, for example, you can have a power data set for days you spend climbing, riding on flats, doing intervals, or even recovering.
We could go on and on about what kind of data you can get from your power meter on your device. There are a lot of power numbers to crunch for training. Power zones, Watts/kg, TSS, IF, kj, normalized power, and on and on. It’s all great stuff, but there’s a lot to know…which gets us to the last word on the subject. Coaches.
We recommend you get a coach to learn how to train with power. The very best reason to get a power meter is to start training with science behind you. In fact, if you get a coach, pretty much the first thing they do is make you get a power meter. It’s not impossible, but it is a lot more difficult to train with power on your own…at least from the beginning. A good coach will assess your power, and be able to configure a highly individualized training program for you that will help you improve your power and performance.
At Cronometro, we’re lucky to be working with some of the greatest coaches in the country and would gladly recommend any one of these outstanding trainers: