You can adjust the transmission range for S-series bike sensors. Adjusting transmission range may enable you to measure speed if you are cycling with an indoor trainer (i.e. stationary bicycle without a front wheel). When you adjust the transmission range to the longest option you can install the speed sensor on the seat stay and the spoke magnet on the rear wheel.
Adjusting the transmission range might cause interference to other cyclists training with Polar speed/cadence sensors.
If you need transmission range adjustment for S-series speed / cadence sensor we highly recommend that send the sensor to an authorised Polar Service Centre where the unit is tested for water resistance after adjustment. Water resistance cannot be guaranteed after an unauthorised service.
The transmission range options are:
min 60cm (parallel)
min 90cm (parallel)
min 110 cm (parallel)
The transmission range options are default measurements.
The range may be shorter when the sensor is installed on a bicycle because the bicycle frame may affect the magnetic field thereby shortening the transmission range.
A longer transmission range uses battery faster.
To adjust transmission range
1. Put the unit on a clean, dust-free pad on a flat table surface and open the sensor by removing the two screws counter-clockwise with a small screwdriver.
2. Lift the case off carefully. Hold the sensor cover upwards ensuring that the PCBA (printed circuit board assembly) stays in the case.
3. Remove the PCBA carefully.
4. Adjust the jumper. See the position of the jumper in relation to the transmission range (see pictures above).
5. Make sure that the jumper is securely attached to the pin(s).
6. Put the PCBA back into place.
7. Make sure that the sealing ring is not damaged and is in its groove. Replace the sealing ring, if necessary. Silicon paste can be used to keep the ring in place. Replace the case.
8. Put the two screws in their holes and tighten them first to 0.5 kgf.cm, holding the case level while tightening the screws. Do not force the screws or damage the existing threads.
After tightening both screws to 0.5 kgf.cm tighten them to 2.0 kgf.cm.
9. Test the sensor by checking that it gives out an orange flash when the magnet passes the sensor.