Listed below, are the most important aspects when looking to select the right power-meter for you and your bike. In essence, practicality and reliability should over-ride the other aspects, although cost may be compromised on stricter budgets, typically, you get what you pay for. However, more expensive units DO NOT necessarily turn out to offer more reliance or extra features, so effective choice should always be a case of doing your own research on a needs basis. The main scientific and practical considerations are highlighted, in no particular rank of importance, to help you along that process:
- Reliability – Is the consistency of measurement (i.e. good precision) claimed by the manufacturer confirmed through objective, reliable data from a third party? Typically +/-1.5-2% is an acceptable level of precision although the level of accuracy may be grossly different, see next point.
- Validity – Is the accuracy of the measurement close enough to what the actual ‘calibrated’ measurement should be? This is the most questionable and important aspect of power meter, if it is not reading a true power then your unit is effectively useless.
- Calibration – To remain accurate and reliable, a power meter needs to be both internally and externally calibrated by the user or sent back to the manufacturer, which may pose some inconvenience depending on preference. This should not be confused with an auto or manual zero-check function which is totally different.
- Manual or auto-zero/ offset– Not to be confused with calibration as highlighted above. A high calibre power meter should have both auto-zero and an internal calibration function, but may come at a premium cost.
- Cost – The general trend is for less expensive devices, as the market is still expanding. Newer providers with less market track-record in quality, enter at much lower prices than more well established companies. More recently, older stalwarts of the industry have re-invented and re-positioned their technology to remain competitive. This should keep the quality of devices and customer services propped up, but hopefully not prices.
- Compatibility – A power meter must be compatible with your bike and fit for purpose. Not all power meters fit all manufacturers components. For example STAGES is not yet offered for Campagnolo and both Garmin and PowerTap pedal systems dictate that you use Look Keo cleats.
- Practical reliability/ function – The device needs to work consistently well and not malfunction in different weather conditions. Factoring down time due to infrequent servicing is sometimes necessary due to the complex nature of a precision measurement device. Battery life and ease of replacement will also come into play as some units are prone to weather dependent accelerated battery use. Position of a power meter is determined by whether it is a crank, spider, pedal or hub-base system. Each of which have inter-changeability issues if your need is to train with power on more than one bike. Clearly a pedal system is the most convenient, but may introduce other limitations, such as cost and durability.
- Weight – Most systems are now almost comparable in weight and does not seem to be a deal breaker when deciding which device. Although more specialist cyclists may favour weight saving options.
You may find a more in-depth analysis for many of the units currently on the market here: