Power meters are sophisticated training tools used by top-end competitive riders to measure and record their power output (in watts). More specifically, ‘direct force’ power meters are units that measure force via an instrument called a strain gauge.
This is recorded and analysed and feeds into the overall dataset which informs the training programme/training goals set out for a pro or semi-pro athlete by their coaching staff or themselves.
If you don’t want to read our in-depth guide on power meters, you can go directly to the relevant product page via the link below:
A power meter is a significant investment, and one usually undertaken by elite-level riders, either professional or competitive amateur. For the majority of recreational riders plenty of training data can be gleaned from your bike computer or heart rate monitor, so if considering a power meter, ensure that you will have occasion to make use of the data it provides.
Compatibility is also a consideration as some power meters (e.g. the spider-mounted types from Quarq) may only be compatible with certain chainsets.
There are two main types of power meter – hub-mounted and spider-mounted (although crankarm- and pedal-mounted meters are also available).
– Hub-mounted power meters are incorporated into a specially-designed rear hub.
– Spider-mounted power meters measure power at the crankset spider. Their manufacturers claim this as the best place on the bike to measure power because all of the riders’ pedaling effort flows directly through the spider and it can be measured with great precision.
Whether hub- or spider-mounted, power meters record power output in watts and transmit this data (via a wireless data protocol such as ANT+ or Bluetooth) to a ‘head unit’ – e.g. a compatible bike computer, a smartphone app or a dedicated device bundled with the meter.
This data can be monitored in real time for training purposes (so that riders know when they are exceeding or underperforming according to the power thresholds set out in their training programme) as well as being recorded for later analysis via PC or app.
Some of the key features to look for when considering a power meter are:
– Power (current, average, max.): Your total power output, measured and transmitted the head unit. Every power meter should have this feature (if it doesn’t, well it’s not a power meter!)
– ANT + support: Support for the ANT+ wireless protocol enables the meter to be used in conjunction with a huge range of head units on the market
– Energy expenditure: Measured in total kjoules.
Power meters may also offer information on other common training metrics including heart rate (current, average), cadence (current, average), speed (current, average, max.), ride time.