Most of us carry a pack now but what we carry seems to vary enormously. Although it should change with each ride some of us do not even change with the seasons. This Deuter super bike large pack weighs can total 7kg on a longer day with a sandwich, energy bars and 3 litres of water; or about half the weight of a lightweight bike! It contains an elastic helmet strap and a reflective rain cover which is used constantly keeping everything dry and mud free and is very reflective in headlights.
Inside it always has:-
Extra lightweight Waterproof jacket
Lightweight windproof gilet
Glasses with 3 colour lenses
Spare tube (slime!)
Multitool Alien DX
Chain links, spare pin, sram power link, disc rotor wipe, brake pad spring
Puncture kit and levers
Magnet (or don’t you drop anything?)
Co2 inflator with spare cartridge
Zipties
Small cloth
Latex gloves
Emergency lights
Wipes, tissue, giant plaster
Money
Padded phone case
Reading glasses
Occasionally I include a shock pump, mini pump, and spare gps batteries.