SRAM Rival E1 DUB Left Arm and Power Meter Spindle Upgrade your setup to track every watt. Introducing SRAM's most advanced alloy crank design to date, the SRAM Rival AXS E1 Power Meter Spindle is an advanced way to upgrade your standard non-drive crank arm to an ultra-accurate power meter. This SRAM Rival E1 Left Arm and Spindle is purpose-built for riders who demand reliable, high-performance components, and an accurate power measurement for more effective training. The arm and spindle feature a lightweight ( | Sram | Rival E1 Dub Left Arm And Power Meter Spindle 165 (Bb/spider/chainrings Non Included)