Powermeter spiders let you add power measurement to an existing crankset without replacing the whole unit. SRAM's Red XPLR E1 AXS Powermeter Spider installs between your crank arms and chainring, using strain gauges positioned at the spider arms to measure the torque you're applying through the pedals. The spider fits SRAM's 8-bolt direct mount interface used across their Red, Force, and Rival AXS cranks, so if you're already running one of those setups on your gravel bike, this drops right in.

The XPLR designation indicates gravel-specific gearing compatibility. This spider works with SRAM's 1x XPLR chainrings in the 38T to 46T range, which covers the typical spread for mixed-terrain riding. Power data transmits wirelessly via ANT+ and Bluetooth, so it'll pair with your head unit, phone app, or smart trainer software without adapters or extra sensors. The rechargeable battery handles around 400 hours of ride time between charges, and SRAM's AXS app handles firmware updates and calibration.

Accuracy sits at plus or minus 1.5 percent, which puts it in line with other spider-based power meters at this level. Spider placement measures total power from both legs combined rather than doubling a single-leg reading, which tends to give more consistent data across different pedaling styles and cadences. The unit adds about 50 grams to your crankset weight, which is less than swapping to a dedicated power meter crankset would typically add versus a non-power version.... Read More