Great deal on a bike power meter. You can connect to this using Ant+ or BTLE. It is very light. It gives you a cadence and speed sensor built in with the power sensor. Obviously this is just the hub so you will need to build it into a wheel.
I built one up recently and it only increased the weight of my wheel by about 50 grams since I could remove the cadence and speed sensors. Great product.
Here are the specs from Powertap:
- PowerTap GS straight pull hub shell
- 24-spoke rear
- Weight: 320g
- DT Swiss bearings
- Compatibility: Shimano/SRAM or Campagnolo
- Powermeter accuracy of +/- 1.5%
- Field-serviceable electronics
- ANT+ or Bluetooth Smart
- Battery: CR 2032
- 9, 10, 11 speed compatible
Price is 327.60 and free shipping with Prime.