Waterproof Cycling Ruck sack / Rucksack / Back pack / Backpack / Backpacks

edmundane depends really... i don't think most backpacks can beat sthg like scott's x-straps. and considering the cyclist's crouch, whilst good messenger bags put all the load on your shoulders, backpacks mostly put it on your waist - your backbone.

not sure a agree with that, your hips and lower back are much better at holding heavy weight than your shoulders, a good bag will position weight there and spread it evenly across the back as much as poss