Power every ride. SRAM have taken the reliability, elegance and features of Quarq s legendary crank-based power meter and dropped the barrier to entry once again. This new power meter platform is entirely contained within the DUB spindle for clean integration that fits more bikes than ever. It s invisible technology that adds minimal weight and will help you get to the finish line faster and can be used to upgrade any eTap AXS bike to power.Lest crank arm only - power meter upgrade Rival D1 DUBAn elegant integrated designDUB-PWR spindle-based unit measures left side power to calculate total wattsProven Quarq reliability and accuracyLong battery life (400+ hours) to power a season of ridesUser replaceable lithium AAA batteryDUB bottom bracket adds durability and simplicityWaterproof (IPX7 waterproof to 1 meter for 30 mins)Lightweight (less than 40g heavier than standard crankset)Simple and affordable power meter upgrade optionSPECIFICATIONS:Speeds: n/aCrank arm length: 160mm, 165mm, 170