My Garmin Edge Cadence Sensor fits perfectly on the derailleur mount. I had been using the derailleur mount as a hand hold to aid in mounting & dismounting the trike. Well, I still can, but with less surface area. This location is perfect for a crank-mounted magnet. Of course, I separated the speed sensor as I have on my other 2 ‘bents. The speed sensor is mounted on the Catrike speed sensor arm on the left spindle.