Does anyone use the cadence sensor with their Garmin forerunner? How and where does it assemble to the bike? On the fork like a cyclocomputer? And if you already have a bike computer (without cadence) will it interfere or be too crowded?
Correct, the cadence sensor mounts on the left chainstay and it includes a wheel speed sensor.
The sensor links with the main unit, so interference form other devices should not happen. When the unit is trying to make the initial link, other units in the immediate area will confuse it. Once that step is done, no problems.