A dual-sided pedal-based power meter for road cycling can deliver detailed, specific, accurate and reliable power measurement. To deliver data that triggers Garmin's advanced Cycling Dynamics metrics, you need a to measure power from each leg, and while some people may not need or want that level of detail, there are others who will embrace the benefits. For road pedal/cleat bodies, Garmin is offering two versions, one set-up for Shimano SPD-SL cleat compatibility (RS200), and this RK200, which is for Look Keo cleats. All other key aspects and most details are the same. Garmin previously offered the Vector series power meter pedal system, and the Rally-series are built from the development and hard-earned lessons from the Vector 3. The axle design of the Rally series, which carries the power measurement devices, communication gear and replaceable battery is a physical match for the final version of the Vector 3 design. It is true the Vector 3 had some issues, but these were related to the battery system. Garmin has worked through iterations to correct this, and by all accounts, the final Vector 3 solution has been effective. There was never an issue with the accuracy of the Vector 3, so Garmin knew it had a proven measurement system. The battery itself, the battery port cover and seal, as well as the threaded receiver in the pedal body have all been fully updated in the Rally series.

One major selling point of the Rally is the fact that the axle system is universal to all Rally pedal bodies, both R and XC models, and is backwards compatible with the Vector 3. This allows the bodies to be interchangeable as all have the same bearing system as well. So if you have a Vector 3 and want to convert it an SPD mountain body, which offered as complete pedals or an upgrade body set, you can use the existing axle to make the change. Or, if you normally use road pedals most of the year, and mountain pedals in the winter, as many cyclists do, you could change out the bodies and have all the same power measuring benefits year round. This modular system offers this benefit, and potentially other options down the road, if you will.

The Rally RK200 pedals install like any pedal and have wrench flats for a standard pedal wrench. There is a torque spec recommended (34Nm), which is bit more than most pedals recommend, but torque won't impact the power measurement. Just make sure the pedals are tight. With the Rally 200 series pedals there are power meters in the spindles of both pedals. As these install like any other standard pedal, it is easy to swap your RKS200's from bike to bike. You are then free to build performance by measuring power and cadence via the various metrics and processing done via your head unit. In the dual meter set-up, the right pedal communicates with the left, and the left communicates with your computer head unit, so only the left pedal can be used as a single sensor option. As far as choosing SPD-SL versus this Keo version, if you already ride Look pedals/cleats it keeps things simple, Garmin does provide cleats, but all Look Keo cleats are 100% compatible. Some cyclists prefer the slightly larger cleat platform of the Shimano system over the Look Keo, but many Keo riders feel just as strongly about that design. This comes down to preference and most likely what you use now.

As far as accuracy, the Rally RK200 has been tested at +/- 1%, which is the equal of the best power meters on the market. Garmin equips them with both ANT+ and Bluetooth communication so you have ease of set-up. Generally we recommend using ANT+ for stability and simplicity, especially with Garmin Edge GPS head units and compatible wearables, but you have options. Pairing is generally fast and simple. Generally you will performing field calibration regularly, and at release Garmin recommends allowing your bike to acclimate to outdoor temperatures for 10-15 minutes. This allows the temperature compensation to be more accurate. As mentioned, the Rally 200 pedals transmit power and cadence, with speed coming from GPS for most users, but you can always had a speed sensor to your bike if you prefer direct measurement. Battery life varies but is rated to 120 hours. It is easy to change the CR1/3N battery via the compartment cap on crank end of the pedal axle. Garmin does have a weight limit on Rally pedals, at 231.5 lbs. The set-up is rated to the IPX7 level for water protection, which means it can stand submersion in 1 meter of water for 30 minutes, so the seals can easily handle even the rainiest days and wet roads.

Given the nature of today's stronger communication standards and compatibility across systems, the Rally 200's are very user friendly with Garmin/Tacx family equipment and apps, as well as third-party apps such as Strava, TrainingPeaks®, TrainerRoad and many more. Training with power can truly teach you about your strengths and weaknesses as a cyclist, and most coaching and advanced training programs utilize power as a primary metric because it is consistent to your physical output and is does not vary with physical variables (hydration, etc) that can affect heart rate, which was used as the dominant measure before power meters became more accessible and accurate. Whether or not you race, a dual side pedal meter system with Cycling Dynamics can teach you about left/right power imbalances, your power zones throughout each pedal revolution, show you weakness or imbalances resulting from injury- and help you train them out. If you value this level of detail and accuracy side to side, the Rally RK200 pedals will become your most effective training partner.