Thanks @
WheresWaldo.
Zip ties are not going to allow me to remove the sensor to clean the bike as often and thoroughly as I like. I'd like a second sensor anyway so that I don't have to swap the one sensor between bikes.
For now I wrapped the rubber bands around the bub twice. Had to get my hands between the spokes, pull the rubber bands around the hub twice with the tips of my fingers... was a PITA.