POWER METERS 4 de 6 - POWER 2MAX

http://www.cyclingpowerlab.com/PowerMeterReviews.aspx

As with the SRM & Quarg the Power2Max is a crank based power meter however this one comes with a significant difference - price. Assuming you buy a Power2Max integrated into a Rotor 3D+ crank, possibly the most popular and aesthetically pleasing of several options, this system will set you back just £1000. Add around £100 for some chainrings (not supplied), around £200 for a Garmin Edge computer, and you can enjoy the benefits of power for a price that comes close to that of a G3 PowerTap. The Power2Max hasn't been around for long and comes from a relatively anonymous German company (doesnt so much great engineering?) but early reviews suggest this system lacks little in terms of build quality, accuracy or reliability. Given the limitations of hub based power measuring technologies such as the PowerTap (loss of freedom over wheel choice and the smaller matter of power loss in the drivetrain) we feel this device represents a serious option at it's price point.

Appearance
Manufacturers Site	www.power2max.de
Data Measured	Speed, cadence, HR, power, ride time. Max and average (as applicable). Kilojoules energy spend.
Variants	Available as a stand-alone chainset spider from EUR 690 but most will purchase a unit ready-integrated into one of several possible chainsets.
Power Unit	Integrated into a special chainset spider. 4 strain guages.
Head Unit	At the time of writing there is no dedicated head unit. Any ANT+ compatible computer will suit such as the Garmin Edge 500 (pictured).
Installation	Replacing a modern crankset is fast and easy requiring no special tools however note that the Power2max is generally supplied without chainrings so you will need to fit these. The Power2max measures cadence via an innovative on board accelerometer so there is no magnet to site as with the SRM & Quarg.
Software	There is no proprietary analysis software from Quarg necessitating a separate purchase of TrainingPeaks WKO+.
Reliability	The first units began shipping in 2011 so there is not much of a track record to comment on here. The comments we have seen indicate, so far, consistent and reliable power numbers.
Price	Integrated into a Rotor 3D+ crank you will pay £1000, plus circa £100 for chainrings. Add £200 for a Garmin Edge 500 computer (pictured) and £80 for WKO+ and the "on the road" price is £1380.
Service	Contact the supplier.
Accuracy	Claimed accuracy is +/- 2% assuming good calibration and setting of the "zero-offset" before every ride. This unit has an auto-zero capability which cannot be disabled - some users have expressed concern about risks to accuracy.
Calibration	At the time of writing we understand the field/user calibration is not possible.
Weight Penalty	A Power2max spider compatibible with the Rotor 3D+ chainset weights 470 grams compared to the original spider at 264 grams. Weight penalty 206 grams.
Who uses one?	The manufactuers website reports thant Susanne Buckenlei won the Norseman 2011 with a Power2max.
Top Reviews	Steve Irwin