Instructables has a simplistic way of carrying your papers on a bike without ruining them. I think the easiest way to do this would be to put a folder in a backpack, but if you didn’t want to deal with the extra nuisance of carrying a backpack, this would be a great alternative. The process requires wrapping the papers around the bicycle frame and securing them with some velcro. Pretty simple, but pretty useful.
How to take papers on a bike – [Instructables]