Hey, just bought a new bike and switched my computer to the new bike. It had not been used for about 9 months so I replaced all of the batteries. I switched the wheel size and have played with adjusting the sensor with no success. I am well within the distance limits between the computer and receiver. Not sure what to do now unless the sensor and receiver are too far away?

Magnets also get weak over time. Most bike shops have these things lying around.