@ Noobtastic: The backpack differs in weight all the time. One time it weighs kilo's, and the next it weighs next to nothing. Besides that, riding with a backpack for 16 miles per ride isn't fun either. Makes my back sweat like crazy.

@ MK313: That's some great advice you just gave me. I'll have a look, and see what can be made smaller in my 'collection' of stuff.