Designed especially for Shimano®’s Dura-Ace® R9100 series chain rings, 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)