topeak multitool (with built-in chain splitter)
8/9/10spd links
lezyne pump
shock pump
spare tube
wallet
keys
water proof camera
monkey wrench (for bashing stuff)

one of these…

btw, what is this about 20p pieces and HT11 pre-loads?

Don’t usually carry a shock pump.
Only one spare tube in case of tubeless failure (but backed up with duck tape wrapped around pump, a patch kit and a tubeless anchovy set)
Always carry a spare hanger – I’ve seen loads of people snap them
Always carry ID, health card and credit card.

I don’t have a 20p piece, so the two times I’ve had to preload HTII cranks I’ve used a small rock…

Headset press.

Everything else you can do with a rock.

@HansRey – is that a modded Oyster card? Neat.

My bag
on-one cheap multitool with chain tool on it
2 26″ presta tubes
puncture repair kit
a few 20cm zip ties
tiny specialized mini pump (might go back to my blackburn one, as the specialized one is hard work for any tyre bigger than about 2″)
a metre or so of gaffer tape
spare, part used, brake pads + spring + pin
mech hanger

then there’s all the other stuff that I keep thinking of cutting down on but don’t
space blanket
Emergency bivvi
Waterproof
First Aid kit
food
bladder
compass
GPS

Thanks all

Think I have it covered.

timb34, a 20p will undo a HT2 preload washer so you can remove the chainset out in the field. Handy if the chain is jammed in the gap below.