Quarq has simplified and streamlined their power meter systems in conjunction with the release of SRAM AXS Force. The DUB spindle system requires a DUB bottom bracket for your frame, a Crank Arm Assembly, a DUB Power Meter Spider and required/desired chainrings. This item is just the spider, with the DFour Power Meter. The DFour was developed for Shimano Dura-Ace R9100 series 4-arm 110 BCD Asymmetric chainrings. It is compatible with Ultregra R8000 and 105 R7000 rings, but not a visual match. The DFour Power Meter Spider DUB bolts to the Quarq Crank Arm Assembly via an 8-bolt direct mount system, which is strong, stable and highly efficient, while being easy to install/remove.

Quarq's power meters are managed and updated via the SRAM AXS app, which replaces the Qalvin system. Most of Quarq's proven power meter technology carry over, with one awesome, major update- MagicCalibration. This new technology delivers automatic calibration as you ride, with no need to backpedal or manually calibrate through your headunit. Combined with the standard 10K Temperature Compensation, the unit is now not only simple and easy, but incredibly consistent and accurate throughout the ride, at +/- 1.5%. Quarq's power meters have already had a great reputation and track record, with great measurement stability and overall features. Wireless communication options are both BLE and ANT+ so you can use the best set-up for your head unit and data requirements. The AXS APP is accessed for iOS and Android equipped devices via BLE.