Master Card... ;-)
The tool kit...
Seriously, whet I started riding my first ST in the early 90ies I too built a "
big" tool-kit, cut quality ring-spanners to replace the "flimsy" ones supplied in the OEM kit, ground down the cut ends to fit into the handle/tube, packed a 1/4" ratchet kit with selected nuts and Allen bits, spare valve stems, wires, connectors, spark-plugs, zip-ties, duct-tape, etc, etc, etc...
Since
never needing it over the years I simply cut down on ballast and went back to the OEM kit, a Victorinox (Swiss made, like a Leatherman, till current day only used once to remove a Pozi screw from the rear tire), 1~2 tire-cans (now replaced with a Slime-Kit) and a small bulb-set (and when heading to UK or Ireland 4 tie-downs for the ferry and some white electrical tape to block the RHS upward kick of the headlight beams...)
I just rely on really decent regular service and proper "pre-flight checks" during preparations for a tour, where items like brake-pads or tires get addressed if they don't appear in condition of coping with the planned trip/distance... the reliability of the ST is unbeatable...