I think Rick may have been referring to quickshifter sensor, not gear position sensor. GPS is usually buried somewhere in the harness? the sensor that failed you is more than likely the little sensor on the shift linkage rod which is a shift sensor. Unless that is the gps in Ducatis?
1. Tools. I usually carry two identical expansive mechanic toolsets. Sometimes, you need 2x the same socket or one with an extension one without etc.
2. Brake pads. Lots of them.
3. Brake bleeding equipment of your choice. Cannister, clear hose, lots and lots of small wrenches, syringe to reverse bleed etc.
3.5. Pad spreader
4. Spare tire warmers. Just yesterday, I had to loan my spare to guy next to me whose warmer gave out. Happens often.
5. ZIP TIES. THOUSANDS OF THEM.
6. A hose/pump to siphon out gas/fluids
7. Painters tape, duct tape & friction tape of all kinds. I use friction tape on boot contact areas on the swingarm, bellypan etc to keep scratches at bay.
8. Fuses and relays (you should have seen my electrical spares box when I raced Aprilias ha)
9. Tire/wheel combo - I usually leave the front alone, but always carry two rear wheels with rotors/sprockets already mounted ready to go. Just different compounds. Usually one hard one soft.
10. Sprockets. I usually have at least 3 down and 3 up from stock
11. Chain degreaser/lube
12. Helmet visor cleaner
13. Spare oil, brake fluids, water wetter, coolant etc.
14. Hose clamps
15. Full set of assorted hardware. I have 8-10 boxes of neatly organized allen screws, bolts, spacers, washers, nuts etc. Perhaps the most important thing in the trailer.
16. Cordless impact gun.
17. Vinyl gloves so you don't get your hands soiled each time you go near the bike
18. Air gauge, pump
19. Two sets of rear and front stands. I more often than not ride two bikes on same day and so I make sure I have equipment to have both on warmers at same time.
20. Allen wrenches of all kinds. I have t-handle, socket type, regular j-type etc.
21. Star wrenches of all kinds. Because Germans.
.....