Originally Posted by zip22
i'm curious if the people pointing out the things their backpack didn't have (support, wetherproofing, weight distribution, shoulder digging, etc) spent as much on their backpack as their messenger bag. it is pretty easy to find a backpack that doesn't digg in, doesn't shift, and is waterproof.
Hiking and cycling are very different activities, and paying for the R&D a backpack company does to optimize their bag for hiking does not necessarily help you out for cycling... Backpacks are supposed to hang vertically, whereas on a bike with drop bars your torso is at an angle, throwing off the geometry and design of the backpack.
Personally my messenger bag and backpack are approximately the same size, weight, material and quality, with basically the same features. Both are great, but the messenger bag is perfect for cycling and the backpack is perfect for hiking.