Anyone experience this situation? when i was cycling i just heard a loud sound noticed when i arrived it was the GSC 10 antenna broken by the wheel spokes.
if you've lost the plastic part of the speed sensor arm (and the reed switch that's inside it) then it will not work for sensing speed anymore. Generally the best way to install the GSC10 speed arm is to loosen the screw, and turn it down so it tucks beside the chainstay, then retighten the screw. On some bikes that can't be done because the chainstay is too close to the wheel, but those are fairly rare. In those cases you can sometimes make it work by installing the magnet on a drive side spoke.
If your mechanically inclined, and there is enough wire protruding from the GSC, then you could solder on an old (or cheap fleabay) reed switch. Pretty much the same thing on all speed sensors.
