Designed especially for Shimano's Dura-Ace R9100 series chainrings, the Quarq DFour91 Power Meter brings Quarq's next-generation DZero platform to Shimano's latest groupset. Compatible with Ultegra R8000 chainrings.
DFour91 embodies 10 years of Quarq advances in power meter technology, plus new features such as dual Bluetooth Low Energy and ANT+ wireless data transfer, revised circuitry, a new strain gauge design and the Qalvin BLE app.
The DFour91 power meter is a bolt-on upgrade, pairing with the 11-speed Dura-Ace R9100 or Ultegra R8000 chainrings. If you already have a power meter using the 8-bolt interface, upgrade with the DFour91 spider.
Features & Benefits:
- Bluetooth low energy technology and ANT+ wireless data transfer
- AxCad – no cadence magnet required
- 10K Temperature Compensation
- Battery – CR2032, 200-hour battery life, change without tools
- Power Balance
- OmniCal – swap chainrings without affecting accuracy
- 2-year warranty
- IPX7 waterproof rating
- Accuracy – within 1.5%, measuring both legs
- Free firmware upgrades with the Qalvin app
- Designed for Dura-Ace R9100 chainrings. Compatible with Ultegra R8000 chainrings.
- Only 8-bolt power meter owners can upgrade using the DFour91 Power Meter Spider.
Power meters and cranksets on 8-bolt since release:
- Quarq ELSA RS (Aug '14)
- Quarq RIKEN AL (Apr '15)
- Quarq Prime Power Ready Cranksets (Mar '16)
- SRAM RED Power Ready Cranksets (Mar '16)
- SRAM XX1 Power Meter (Aug '14) (Note: Boost spiders should not be paired with 156Q crank arms)
- SRAM RED BB386EVO standard crankset (Mar '16)
Power meters switched to 8-bolt:
- Quarq RIKEN R (Revision AEQ onward, except warranty/replacement – Jul '15)
- SRAM RED (eTap graphics – Jan '16)
- Quarq ELSA R