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Polar Speed Sensor Bluetooth® Smart

There are a range of factors that can affect your cycling speed. Obviously fitness is one of them, however, weather conditions and the varying gradients of the road play a huge part too. The most advanced way of measuring how these factors affect your performance speed is with the aerodynamic speed sensor.

  • Measures your current, average and maximum speeds
  • Track your average speed to see your progress and performance improve
  • Light yet tough, and easy to attach

Pair a Speed Sensor with M450

Make sure the speed sensor has been correctly installed. For more information on installing the speed sensor refer to the user manual of the speed sensor.

There are two ways to pair a speed sensor with your M450:

  1. Go to General Settings > Pair and sync > Pair other device and press START.
  2. M450 starts searching for the speed sensor. Rotate the wheel a few times to activate the sensor. The flashing red light on the sensor indicates that the sensor is activated.
  3. Once the speed sensor is found, Polar SPD xxxxxxxx is displayed.
  4. Press START, Pairing is displayed.
  5. Pairing completed is displayed when the pairing is ready.
  6. Sensor linked to: is displayed. Choose Bike 1, Bike 2 or Bike 3. Confirm with START.
  7. Set wheel size is displayed. Set the size and press START.

    The first cycling sensor you pair will automatically be linked to Bike 1.

or

  1. Press START in time view to enter pre-training mode.
  2. M450 starts searching for your speed sensor. Rotate the wheel a few times to activate the sensor. The flashing red light on the sensor indicates that the sensor is activated.
  3. The device ID Pair Polar SPD xxxxxxxx is displayed. Choose Yes.
  4. Pairing completed is displayed when the pairing is ready.
  5. Sensor linked to: is displayed. Choose Bike 1, Bike 2 or Bike 3. Confirm with START.
  6. Set wheel size is displayed. Set the size and press START.

Measuring Wheel Size

Wheel size settings are a prerequisite for correct cycling information. There are two ways of determining the wheel size of your bike:

Method 1

Look for the diameter in inches or in ETRTO printed on the wheel. Match it to the wheel size in millimeters in the right column of the chart.

ETRTO Wheel size diameter (inches) Wheel size setting (mm)
25-559 26 x 1.0 1884
23-571 650 x 23C 1909
35-559 26 x 1.50 1947
37-622 700 x 35C 1958
52-559 26 x 1.95 2022
20-622 700 x 20C 2051
52-559 26 x 2.0 2054
23-622 700 x 23C 2070
25-622 700 x 25C 2080
28-622 700 x 28 2101
32-622 700 x 32C 2126
42-622 700 x 40C 2189
47-622 700 x 47C 2220

Wheel sizes on the chart are advisory as wheel size depends on the wheel type and air pressure.

Method 2

  • Measure the wheel manually for the most accurate result.
  • Use the valve to mark the point where the wheel touches the ground. Draw a line on the ground to mark that point. Move your bike forward on a flat surface for one complete rotation. The tire should be perpendicular to the ground. Draw another line on the ground at the valve to mark a full rotation. Measure the distance between the two lines.
  • Subtract 4 mm to account for your weight on the bike to get your wheel circumference.