My bike can be completely disassembled right down to the two wheels and the bottom bracket, which require special tools and large spanners to hold/drive them, with just a 68gr hex bit Topeak Toolbar and one 8x10mm spanner, both of which are in my tool bag. Also in the tool bag, a half inch socket for the wretched "clip" on the Brooks saddle, a Brooks saddle stretching spanner, a Presta to automobile valve adapter in case we want to pump up a pedal pal's tyres at the garage, a small digital pressure gauge, a spokey, an old florin (a coin for opening battery slots on HRM, bike computers, etc), coin battery spares, AAA battery spares for my front flasher (I no longer use a rear flasher), a plastic bag to put over hands if a companion's chain should fall off (mine doesn't) or for paper rubbish (biodegradables like banana skins I throw in the river and face down the self-appointed idiots who patrol the lanes), a single self sticking patch, tyre levers (on the Toolbar). All of this fits in a lady's small leather coin purse and doesn't weigh much. The tools are wrapped in lightly oiled tissues against damp. There is also a pump on the bike but I haven't had a flat in ten years: it is there for pedal pals with less secure tyres than mine. Generally, if it will rain, I'm wearing the rain jacket, so I carry only plastic trousers for heavy rain, and I've worn them once in about five years, and then for extreme cold (ver effective, actually, as long as you keep moving) rather than rain. There's a leather saddlebag for food, and bottle holder for water or lemon and honey tea.
There's no chain tool carried on the bike. What for? It is true that the quick link's promise of being broken and refitted by fingers alone is fraudulent, but if we need to break a chain on the road on a pedal pal's bike for some reason I cannot now conceive of, we'd come home in a taxi and drop the bike off at Joe the LBS on the way for him to fix.
That kit with which Jags started this thread is way, way over the top. Still, as an inveterate tool fondler, I think many of that fellow's tools would look good in my home bicycle toolbox for my current bike, an aluminum pilot's case with tool pallets inserted. They're the sort of tools that one would be proud to own even if you use them only once in a lifetime.
