Our meters are: Lightweight. Downright miniature. Without magnets. Made from the same material as bulletproof glass. Simply put, Stages Power meters employ the most advanced technology in the power meter category, all while being one of the easiest to maintain and simplest to use.
The tried and true non-drive side power meter is as simple and as powerful as they come. With no moving parts, and everything protected by our high-strength ABS-PC housing, the Stages Power L meter preserves the structural integrity of the crank—all while seamlessly adding the ability to measure your power.
TINY: 65mm x 30mm x 10mm
Under 20g: less than an energy gel
Swapping a Stages Power L from bike to bike is as simple as changing the left crank arm—making it possible to have power across multiple bikes.
With no external or moving parts, a waterproof housing, and a user-replaceable battery, Stages Power L meters handle all weather conditions and all riding styles.
Stages Power LR
Rigorously tested with Team Sky, and with 2 Tour de France victories to its name, Stages Power LR provides individual measurement of right & left power.
Stages Power LR FEATURES
With Stages Power R you can transform an existing Stages Power L meter into a dual-sided meter. The Stages Power R adds only 20g to the weight of the crank.
This is the only engineered carbon-based, direct force measurement power solution, and we’ve done it without compromising the functionality or the simplicity of the Stages Power meter.
Measuring Torque, controlling for temperature variables and considering compatibility across bottom bracket options are just a few of the challenges faced when designing for carbon. Our solution is one meter engineered to work with a wide range of cranksets, across multiple bikes and cycling disciplines.
How Power Works In Carbon:
Two separate areas were fully investigated when coming up with a Stages Power carbon solution: measuring deflection accurately and dealing with temperature changes appropriately. Strain gages have been applied to aluminum for a very long time, but carbon fiber is a relatively new material and thus there isn’t a lot of information out there on how to do it properly.
Once a good solution was found in the lab it was validated it with real riding, aka., hundreds of hours putting the meter to real-world tests. As a cycling company, it’s easy to find people that ride and that are critical of their power data.
The results show carbon power meters retain the same accurate Active Temperature Compensation as the Stages Power aluminum models and they relay the same accurate and consistent data as our aluminum models.
The Stages 30mm Spindle for carbon Stages Power cranks match the diameter of your existing crank spindle.
Each spindle varies in length to ensure the new Stages crank arm will be in the same effective position as the one you replaced.
Think about it. Orient your cranks in the same direction and measure the distance from the outer edge of your left crank to your right crank. Different cranksets are designed around different widths depending on their intended use. Mountain bike cranks are usually wider, and road narrower. Our spindles accommodate this change by using the exact length specific to each crankset model.
Each brand makes their crank arm differently. They can have slightly different bends and offsets. Our spindles adjust your left crank position to match your previous crank and ensure your crankset is still absolutely symmetrical.
We call this Q-Factor: The distance between both pedals when they’re installed on your crankset.
Measuring power is simple in a controlled environment, but when you’re out in the elements facing varying climates everything changes. The strain gages used to determine power, whether it be crank based, spider-based, pedal based, etceteras, are highly affected by changes in temperature. If a power meter system does not take into consideration changing temperatures throughout a ride, power will be wildly inaccurate.
Why do changing temperatures affect power? Strain gages are tiny metallic wires laid across a metal crank, spider, pedal etc. It is the flexing of these wires that measure torque. When these wires heat up or cool down in response to external temperatures they naturally expand and contract. This results in false data.
Stages Power meters are equipped with ATC – [Active Temperature Compensation]. Different temperatures cause strain gages to expand and contract a specific amount. ATC allows the power meter to compensate for temperature changes that would otherwise affect the strain gages and their ability to accurately measure force. More importantly, Stages ATC auto-adjusts on the fly, without the need to stop pedaling.
Power is a measurement of the work you do on the bike, and the most accurate way to measure your effort. Unlike your heart rate, which can be widely affected by physiological influences, including: stress, lack of sleep, caffeine, temperature, time of day, dehydration and other factors, power shows exactly how much work you are doing and exactly what you are getting out of your training. Power is the perfect tool to understand how you are progressing and the best indicator of fitness gained and fatigue level. Simply put, if you want to know how you’re doing, check your power.
The equation for power is pure physics:
POWER = TORQUE x CADENCE
P = 2X[(F x 9.8 x L) x (R x .1047)]
P=Power, aka Watts.
TORQUE // Fave x 9.8 x L = Torque
(Fave = Average Force per Revolution )x(9.8 = gravitational constant)x (L=Length of Crank)*
To measure TORQUE, Stages’ proprietary strain gages are laid precisely along the crank arm. These gages, which are the same tool used in aerospace, can detect the smallest flex in the stiffest crank. In this case, every pedal stroke, causes a small amount of flex along the crank arm. This downward force happens in every rotation. This force, multiplied by 9.8m/s2 and the length of crank arm are used to determine the force applied to a pedal stroke, or torque.
CADENCE // R x .1047 = Cadence
(R= Rotations — measured using an accelerometer*)
Using an accelerometer (the same technology used to tell your smart phone how to orient its screen), the Stages meter measures cadence. The proprietary circuitry houses this cadence tool, allowing the meter to eliminate the antiquated need of magnets, external sensors, cables and zip ties to measure cadence. This modern technology also allows the meter to capture multiple positions per revolution, resulting in a faster response and better overall data.
Once Cadence and Torque are collected, they are multiplied together to determine the POWER of a single pedal stroke. We then multiply this number by 2 with the assumption of doubling the left leg power. This one assumption, that both legs produce relatively the same force, is the key factor that allows Stages Power to be more compact, lighter, more robust, and more economical than any other power meter on the market. This assumption has been fair and consistent for most of the riders on the road.
The Stages Power meter is the first power meter to use Bluetooth Smart protocol in addition to ANT+.
ANT+ is the gold standard for over-the-air communication in the cycling and athletic industries. The system is simple, robust, and provides for riders the ability to add power to their ANT+ devices.