If you aren’t already using a cycling power meter to measure your power output then you might be missing out on tracking data points that could help transform your training efficency.
While the technology has been around for over 30 years, training with a power meter is becoming more and more popular and there are more and more units becoming available at more affordable prices.
This is great if you want to be able to measure your real output objectively and keep a close track on your training. They are also more accurate than just using a heart rate monitor.
A heart rate monitor simply measures the effects that exercise is having on your body rather than the actual output you are producing.
You might, for instance, be ill and be training at your normal heart rate but with a significantly reduced power output. Also your heart rate can remain constant during a training session while your power out put is actually dropping off.
With a cycling power meter you can also draw direct comparisons to your cadence and how it performs in relation to your speed and heart rate.
Parts of a cycling power meter
Cycling power meters usually consist of a strain gauge which is usually mounted in the crankset, bottom bracket, or rear freehub.
Types of cycling power meters
The different types of power meters use different methods to calculate the actual power output.
Bottom bracket power meters
Bottom bracket power meters require you to have a separate bottom bracket unit for separate bikes. They are also very hard to change out once they have been put in place. They work in conjunction with a handlebar mounted computer.
The BB shaft has a perforated disc at each end which allow sensors to detect whenever torque is applied to one of the pedals. This method is based on the torsional deflection of the shaft.
Crankset power meters
A crankset power meter requires you to have a specific crankset but is usually quite easy to swap onto other bikes.
There are strain gauges positioned so that they can pick up the torque which is applied to the two pedals. The cadence and gauge deflection allows the computer to then calculate your power output.
Freehub power meters
Much like the crankset power meters, these use strain gauges, however these are placed in the rear wheel hub. This makes them a lot easier to swap with other bikes as long as the wheel is exchangeable.
Due to their placement they can measure a lower power output as compared to crankset meters.
Opposing force power meters
These meters calculate your power output indirectly by taking into account inertia, gravity and occasionally, wind speed.
Chain power meters
It is possible to work out power output backwards from the vibrations in the bicycle chain. The variables that are used are chain speed and tension. The sensor measures the vibrations while positioned on the chain stay.
Direct applied force power meters
These power meters are built directly into cyclists shoe or pedal and measures the forces applied to the pedals as the cranks rotate. This is better than other systems because you can measure the power output each leg separately and you obviously don’t have to replace parts of your bike.
What’s the best type of cycling power meter?
Each type of meter has it’s advantages and disadvantages so it’s important to consider exactly what you want to do before committing to a setup. Will you want exact measurements for both legs? Will you only be using it on one bike? How accurate do you need the setup to be?
We’ll be publishing detailed product recommendations and guides for the different types of power meters available shortly.
Do you have a favorite setup? Let me know in the comments.