I have a hub mounted Garmin speed sensor for use with Edge, the kind pictured below. The rubber bands on the sleeve are too long for the small diameter hubs on one of my bikes. Both front and rear hubs are only about 3/4" diameter and the sensor sleeve fits rather loosely around the hub. It grips okay in the dry but slips in the wet as the wheel rotates resulting in lower than actual speed readings.

Can anyone recommend a speed sensor which will work with Garmin Edge which might fit tighter around a small diameter hub? I don't want magnets or wires.