Last year I did 3 weeks around Europe with a tail pack and a ruck sack.
The biggest pain are shoes. They're so bulky. If you think you can manage without them just take flip flops.
Poundland do compression vacuum bags. Great for making clothes take up less room.
Obviously small tool kit, tyre weld, cable ties, duct tape.
I always carry a chinograph pencil to write directions on the tank and have a mini compass on my glove. Invaluable when my sat nav stopped working in Estonia.
Get a Merino wool base layer. It never smells and will keep you warm even if it gets wet.
If I think of anything else I'll let you know!
