Stages power meters are exploding in popularity thanks to their affordability, simplicity and light weight. Stages is a left crank arm based system with a 20 gram unit bonded to a factory aluminum left crank arm. Stages power meters are ANT+ and Bluetooth compatible to work with a host of devices present and future. The Stages Power meter is assembled to a variety of Shimano road and mountain cranks - from 105 to Dura-Ace 9000, as well as XT, XTR, Saint and DXR. There are also options for SRAM Rival road, X9 mountain for both road and mountain use (Stages cannot be attached to a carbon fiber crank).
The engineers at Stages found with thousands of miles of testing power differential between legs has no significant influence on ride data and its value as a training tool. This helps to significantly reduce the complexity and cost while providing power measurement with ±2% accuracy. Stages's assumption of symmetry also gives major advantages over spider based torque measurements which are forced to add complex algorithms or geometries in order to filter out unwanted torque measurements coming from chain line and crank position. Because Stages constantly corrects for temperature, its accuracy is much better over its competitors whenever there is a significant change in temperature during your ride.
A super-tough housing is made of a polycarbonate blend similar material to that used in bulletproof glass and sport sunglasses. This material is perfect due to its superior durability and flexibility so there is very little chance of breaking the housing before irreparably damaging the crank. Additionally, the Stages Power meter is highly sealed against environmental conditions plus firmware updates are accomplished wirelessly with an iPhone 4S or iPad 3 (or later).
Installation is as easy as throwing on a left crank arm. The Stages Power meter does not require any additional mounted hardware, save for the unit itself - no zip-ties, no magnets. The Stages power meter let you use a crank that is the exact match to your drivetrain for the best front shifting without compromises. You can use any wheel that suits the ride of the day. For cadence, it uses an accelerometer that tracks crank position to calculate each rotation. The self-contained unit means installing the meter is as simple as replacing the non-drive crank arm, pairing the power meter to a compatible head unit, and then getting out to ride.
Stages limits sales to in-store pick up only - 2045 32nd street, Boulder, CO 80301 (9-6 M-F, 10-6 Saturday, closed Sunday). We cannot process internet sales and/or ship Stages Power meters due to these restrictions.