SRAM Red AXS E1 Power Meter Spider for Threaded Mount Chainrings

The SRAM Red AXS E1 Power Meter Spider for Threaded Mount Chainrings is a spider-based power meter built specifically for SRAM Red AXS cranks running the Thread Mount chainring system. It measures total output from both crank arms through the spider at ±1.5% accuracy, held consistent across temperature variation via 10K temperature compensation. For riders already on Red AXS who want to add power data without changing crank arms, it's a direct upgrade.

The Thread Mount system is central to how this spider is designed. SRAM's proprietary thread-on chainring attachment is lighter and stiffer than a bolt-on BCD interface — and it still allows chainring swaps across the 38T–46T range without pulling the crank. The spider installs on your Red AXS crank arms and replaces the standard spider, adding the power measurement hardware without meaningfully changing the weight or feel of the build.

MagicZero automatic calibration runs continuously in the background as you ride, rechecking and adjusting without any manual zero required at the start of each session. Cadence is measured internally — no magnet needed. A user-replaceable CR2032 battery powers the unit for 200 hours, a significant advantage over rechargeable systems that need to be charged between rides. Data transmits simultaneously via Bluetooth Low Energy and ANT+ to head units and training platforms. The AXS app handles firmware updates and provides monitoring alongside your cycling computer. Waterproofing is rated to IPX7 — submersion to 1 meter for up to 30 minutes.

Specs at a Glance

• Measurement type: Spider-based, dual-sided total power
• Accuracy: ±1.5% (10K temperature compensation)
• Chainring compatibility: Thread Mount, 38T–46T
• Crank compatibility: SRAM Red AXS crankset arms
• Battery: CR2032, user-replaceable, 200-hour life
• Connectivity: Bluetooth Low Energy + ANT+
• Calibration: MagicZero (automatic, continuous)
• Cadence: Internal measurement, no magnet required
• Waterproofing: IPX7 (1 meter, 30 minutes)
• App: SRAM AXS — firmware updates, monitoring

Design Benefits

1. Thread Mount keeps chainring swaps easy. The proprietary thread-on system is lighter and stiffer than bolt-on BCD, and you can still swap rings across the 38T–46T range without removing the crank — useful for riders who run different chainrings for different courses.
2. MagicZero eliminates the pre-ride zero ritual. Automatic background recalibration means one less thing to remember before rolling out. Accuracy is maintained without manual input.
3. 200-hour replaceable battery. No charging schedule, no dead meter mid-block. CR2032s are widely available and inexpensive to keep on hand.
4. Dual protocol transmission. Simultaneous Bluetooth and ANT+ means the spider talks to any head unit or training platform without reconfiguring or choosing between protocols.