Shimano's development of the Dura-Ace Di2 electronic shifting system makes gear changes faster and virtually eliminates missed shifts, but the force on the chainrings is much higher than before. Therefore Shimano developed new DuraAce 7950 compact chainrings which are significantly stiffer. If you ride Shimano DuraAce 7950 conventional or Di2 - you benefit from increased power transmission.
Team HTC Highroad, Team Leopard and Team Sky rely on the SRM PowerMeter DuraAce 7950 compatible - especially for the hard mountain stages in the Giro D'Italia.
Crank: Shimano DA-7800, Cranks are available in lengths of between 165 - 180 mm
Chain Rings: Shimano DuraAce 7950
Bolt Circle Diameters: 110 mm
Compact: 34/50 All other chain ring combinations are available at an extra charge
Bottom Bracket: Shimano FC-7800 (weight: 98 g) or FC-7900 (weight: 90 g) - Not Included
Weight: 855g with PowerMeter, crank, chain rings and bottom bracket (90 g)
Strain Gauges: 8
Cadence Range: 30-255 rpm
Wattage Range: 0-4096 Watts
Wireless Protocol: Wireless ANT+ Sport
Accuracy: +/- 2%
Battery Life: 1400 hours of use
Compatible wireless with PowerControl 7 and PowerControl VI.