The SRAM GX Eagle power meter crankset arrives as a complete unit, both crank arms, spindle, chainring, and integrated power measurement, rather than requiring a separate upgrade to an existing crank. Two independently removable composite bashguards protect the crankset from scuffs and impact on rough trail, while Quarq's DUB-PWR spindle measures left-side power at a stated +/- 3% accuracy without adding a separate component to the build. What Our Gearhead(R) Experts Are Saying:"I've dragged this crankset through a full season of rock gardens, and the bashguards take the hits so the arms underneath don't have to. The power numbers have never wavered through any of it, so I trust the data as much as I trust the crank to survive the ride."