If you do any type of long distance touring, there is a certain comfort level to having spare parts with you, and if you never use them, so much the better! I do a lot of trips including an annual ride with 12 or more long time friends that typically is 4000+ miles and quite often find ourselves 100 mile this side of no-place. As part of our pre-trip planning we will assemble an assortment of spare parts (we all ride HD) that includes Emergency Drive Belt, tire repair/plug kit, compressor, voltage regulator, spark plugs, cables, oil, bulbs, fuses,wire, splice kit, tape, tyraps, liquid gasket maker, tools, etc. etc. We then divide everything among all the riders and make a list of who has what. This has saved the day on many an occasion, and the emergency drive belt was used on a Road King with only 12000 miles on it. If these parts do nothing more than get you to the nearest town they are worth their weight in chrome!
Tom P