How to choose your power meter?

In the 1990s, the power meter revolutionised training in the cycling world. This performance measurement tool collects, processes and provides a wealth of precise and reliable data of great value, both for the competitor and their coach. As a result, it has since established itself as an indispensable and undeniable instrument for those who wish to optimise their training, improve their performance and reach their goals. Here are a few tips to help you find your way!

What benefit does it offer the cyclist?

The power meter offers the possibility of evaluating yourself across a whole battery of tests: velocity, force-velocity, Wingate tests and MAP... These data allow you to determine intensity zones and adapt your training programme. Specific sessions are thus carried out with greater precision, and their quality and results can be verified.

The power meter also proves extremely valuable in competition as it allows the cyclist to better manage their effort throughout the race, during attacks, breakaways or time trials. Collecting data during a race allows performance to be analysed in the finest detail. And, since performances achieved in competition are often the best, these can subsequently be used to adjust the training programme.

What advantage over heart rate?

The main advantage of the power meter is that it allows you to free yourself from many external constraints that have a direct impact on an athlete's heart rate: heat, stress, fatigue, hydration, nutrition, altitude… These influences are difficult to quantify, and as a result, the quality of training can be called into question.

Power is a raw and objective measurement that no external factor can influence. Heart rate data nonetheless remains useful and complementary for the coach and for monitoring the athlete's progress.

How does a power meter work?

Power (W) = Torque (N.m) x Angular velocity

Power meters base their technology on the principle of strain gauging, that is, the measurement of deformations. Mechanical power is measured through the deformation of strain gauges. Thanks to the constant deformation of these calibrated components, the system measures the torque (in N.m).

The measurement of angular velocity depends on the component in which the power meter is integrated. For a crankset or pedals, for example, it corresponds to the pedalling cadence, whereas for a hub, it corresponds to the rotational speed of the rear wheel.

Regarding data transmission, most power meters are compatible with computers equipped with the ANT+ and/or Bluetooth Low Energy (BLE) data transmission protocol. Some brands also offer compatible applications for other devices (e.g. smartphones or tablets).

Types of power meters

The power meter offers the possibility of evaluating yourself across a whole battery of tests: velocity, force-velocity, Wingate tests and MAP... These data allow you to determine intensity zones. It is now possible to find a power meter in almost any component of the bike: hub, crankset, cranks, pedals, bottom bracket axle or chainrings. Each one presenting advantages and disadvantages:

Measurement on the crank (one side only)

Marketed as one of the most accessible options, it should be noted that when the power meter is present only on the left crank, the system makes a compromise and may prove less accurate in certain cases.

Indeed, a difference in the power generated by each leg can exist. One may be stronger or more fatigued than the other (for example, a ratio of 48 / 52%) and vice versa, and this phenomenon can be accentuated with fatigue. This ratio can also vary depending on the type of effort (flat / climb) and even cadence.

A sensor measuring only the left leg obtains the final value by multiplying the recorded measurement by two, and therefore does not take these possible variations into account. However, this system offers broad compatibility and installation is very straightforward.

Measurement in the crankset (or chainrings)

This is the most widespread and currently approved type on the market, but also, in general, the most expensive.

This type of power meter measures force close to the point of pressure, which is an advantage. Models are constantly evolving to refine design, compatibility, component weight, energy optimisation and durability.

Also available on the market is a hybrid product: the system is directly integrated into the chainrings, allowing you to keep your own crankset (compact only) whilst offering a very competitive price.

Measurement in the hub

The power meter located in the rear wheel hub is one of the first to have received genuine scientific validation. It proves very practical when you use several bikes. Transferring from one bike to another is very straightforward. Teams and committees have widely adopted it to assess the potential of their cyclists.

This advantage can become a constraint if you use several wheel profiles during your training sessions and races.

Measurement in the pedals

This type of power meter offers numerous advantages. On the one hand, the measurement is taken as close as possible to the power developed by the cyclist. On the other hand, this system allows for a separate measurement for each leg (left/right). The dissociated measurement also allows for a very detailed analysis of the pedalling cycle. You will then be able to work on your pedal stroke and improve your technique. Furthermore, when the sensor is located on the pedal axle, they can be quickly and easily swapped from one bike to another, making this option well suited to an athlete who owns several bikes.

Bluetooth, ANT+... Which protocol to choose?

The choice of protocol is not a decision to be taken lightly.

ANT+ is an open protocol. This means it is accessible to all manufacturers. This is why it has become a standard and is available on the vast majority of power meters. This protocol continues to improve and now offers faster connections and optimised energy consumption.

Bluetooth (BLE) is increasingly widespread and is available on several power meters. It offers more possibilities in terms of data transmission and the transfer rate is faster.

Since 2015, a dual-emission chip (ANT+ and BLE) has been available in certain power meters, offering you total compatibility. The choice is yours depending on your accessories: computer, smartphone, heart rate strap...

Which power meter for my discipline?

Drawing on the experience of our teams, our range is made up of the best power meters on the market. Each model is designed to meet different needs and expectations.

To make the right choice, we advise you to take all of the following criteria into account: budget, frequency and type of use, number and type of bikes you have, as well as the equipment you use.