Maps
Clothes hangers and pegs (for drying stuff)
Plastic boxes
Coffee mate
Coffee
Power extension lead for phone chargers and stuff
Towel
Casual jacket
Full face helmet
Xc helmet
Earplugs
Blankets
Camelbak bladder
Camelbak
Energy bars, gels, and drink powder
Proper food
Camera and charger
Phone and charger
Sat nav
Shower gel, toothpaste, deodorant, toothbrush, etc.
Clothes!
Spare tubes and tyres
Tools, oil, grease, pump, etc
Cigarette lighter
Bike videos!
First aid kit
Bike lock and spare key
Pen and paper
Ibuprofen or your preference of painkillers
Booze
This list.