Heart Rate Monitors - We stock all 67 Polar heart rate monitor models!

SUMMER SAVINGS EVENT 2010

Polar Power Watts Output Kit

Power Kit fits these models:
S625x, S710, S710i,
S720i, S725 & S725x

Call 1-888-477-6527 for guidance.


$299.95

(see details below)

*FREE SHIPPING on all Polar Heart Rate Monitor Kits

POLAR POWER SYSTEM

Measure Power Output and Cycling Efficiency
The Polar Power System will help make you a better cyclist. This system combines heart rate and wattage with a pedaling efficiency index to take your training to a new level. It also features a left and right pedaling index to smooth out your pedal stroke. The lightweight 222 grams (.748 pounds) advantage of the Polar system makes it an unique option for training or racing. No hubs or cranks to change.

How The S720i Measures Power:
The system derives wattage from the chain, not from the crank or hub as other models do.

The system works by measuring two key factors:
      Chain Tension - measured using a sensor on the chain stay
      Chain Speed - measured using a sensor on the rear pulley

POWER = chain tension x chain speed

All the drive force of the bike is transmitted through the chain, allowing the S720i to calculate watts very accurately. The sensor positioned on the rear pulley works magnetically and measures the speed of the chain. The chain stay sensor calculates the tension of the chain by measuring the vibration as it passes over the sensor.

(The user will enter one time during set up: chain length, chain weight and the measurement between the bottom bracket axle to the rear wheel axle. A chart in the manual will help provide some standard parameters.)