The Polar S-1 foot pod computes speed and distance information for either the
S625x or S725x heart rate monitors. The S-1 Foot Pod technology is highly accurate - - It is not a pedometer, it does not count steps, nor does it rely on an equal stride length. The Polar footpod measures 360 degree, 3-D, forces of inertia (speed, magnitude, impact, direction etc). These sensitive accelerometers then translate these measurements in to
real time speed and distance -- with approximately 95-97% accuracy.
Polar
S-1 Foot Pod $119.95
for use with S625x or S725x
Cadence Sensor:
Allows you to view the number of pedal revolutions per minute and
total pedal revolutions per exercise session. Data is sent via
wireless transmission to the S-520, S625x, S-720i & S725 models. The Cadence
sensor is an
optional accessory.
Polar
Cadence Sensor $39.99 (for
use with S-520, S625x, S-720i & S725x
Speed Sensor:
The speed sensor measures bike wheel revolutions. Data is
sent via wireless transmission to the S-520, S625x, S-720i, S725 watches. Trip meter and Odometer with Total riding time. Average and Maximum Speed.
The speed sensor is included with S-520, S-720i & S725 models. A
speed sensor is also included with the power output sensor (
listed below )
Polar
Speed Sensor - $29.95
(for use with S-520, S625x, S720i &
S725x)
Power Output Sensor.
The Power output sensor measures power out put and and speed and
works with the Polar S625x, S710, S720i or S725x.
The system derives wattage from the chain, not from the crank or
hub as other models do. The systems 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
The
system provides a real time readout of Power in watts that is +/- 5%.
POWER
= chain tension X chain speed.
All of the drive force of the bike is transmitted through the chain,
allowing the S625x, S720i & S725x 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.)
Measuring Left Right Pedaling Power balance
The S625x, S720i & S725x system allows a cyclist to track the efficiency of
their pedal stroke in real- time. It measures the power distribution
generated by the left and right foot respectively, and provides
a constantly updating index number that appears on the receiver
face. If a cyclist presses hard on the right, the index number will
be skewed on the right side. This constant measurement will help
the cyclist evenly distribute power between both pedals.
Polar
Power Output Sensor $349.99
(for use with S625x, S-720i & S725x)