The more space you create, the more unnecessary crap you will pack. My mates can barely close their 56l top boxes and always have both panniers full. That's just for a bank holiday trip. Make sure all your clothes are quick dry technical fabric. Get one of those M&S feather jackets that you can roll up and jam in a small bag, it'll double up under your bike jacket or do for chilly nights. Only take shorts in the summer. Get those vac pack bags and you're done. Finally, don't take a woman with you as you'll never have enough space and there are plenty of those abroad.
