They are finally available. Shimano's first ever powermeter. And they have come out of the gate with a winner!
Shimano:
https://www.duraace.com/global/en/power-meter
Bike Radar First Ride Review:
http://www.bikeradar.com/us/road/gear/category/accessories/power-meters/product/shimano-dura-ace-r9100-p-power-meter-review-51582/
Specs:
- ±2% accuracy of strain gage measured power
- Dual Sided Measurement
- Both left and right side connected with cable
- Bluetooth and ANT+
- Simple zero reset with switch on transmitter
- Integrated rechargeable battery
- Simple re-charging
- Easily change chainrings without affecting power meter performance
- Wireless firmware update system
- Waterproof in all conditions
- Stable power measurement system at the various stepping positions
- Quick response and operation without stress; Possible to start quickly
- Direct response
- Crank arm length: 170, 172.5, 175mm (w/ chainrings)
- Gear combination: 50-34T, 52-36T, 53-39