Wahoo Blue SC Cycling Speed Sensor for Road, Gravel and Mountain Bikes;

How to install the Wahoo Blue SC:   Place the sensor on the rear chain stay of your bike, near the pedal. The logo should be facing up and the arm of the sensor should be inside the rear chain stay, facing down. You may need to loosen the arm of the sensor with a 2mm allen wrench to move it into the correct position. Secure the sensor in place with the provided rubber band or zip-ties, whichever is preferred. If using zip-ties, do not completely tighten yet as the magnets still need to be aligned before completely securing the sensor in place. We recommend using the zip-ties for the most secure connection. Take off the pedal on the same side and slip the pedal magnet onto the crank, magnet facing in towards the sensor. Align so that the magnet will pass by the indicator line on the body of the Wahoo Blue SC sensor. The magnet will have to pass within 1/8 inch (about 4mm) to get a reading. As such, adjust the position of the sensor and/or magnet if required. Replace your pedal. Screw the wheel magnet onto any spoke on your back wheel, facing in towards the sensor. Align so that the magnet will pass by the indicator line on the arm of the Wahoo Blue SC sensor. The magnet will have to pass within 1/8 inch (about 4mm) to get a reading. Once again, adjust the position of the sensor and/or magnet if required. Tighten the magnet in place on the spoke. Once satisfied with the magnet positioning, tighten and snip the ends of the zip-ties (if using).