The SRAM XX Eagle AXS Transmission power meter adds power measurement to a carbon crank arm and connects directly into a Flight Attendant setup, so power data becomes part of the same connected system that's already reading terrain and adjusting suspension. Quarq's DUB-PWR spindle measures left-side power at a stated +/- 3% accuracy, and it works with any chainring setup rather than locking a rider into one specific gearing choice. What Our Gearhead(R) Experts Are Saying:"I've pulled numbers off this power meter through rough, technical terrain where the pedal stroke never stays smooth, and the readings still hold up against a lab-verified reference. Three percent accuracy means I trust the wattage on a rock garden the same as I would on a fire road climb."