+1 on the leftovers, I have two panniers one has a change of clothes with rain gear just in case. The other has tupperware with lunch, an apple, a banana, yogurt and a 1L bottle for water at work. All and all I think my Cross check weighs in at 35-40lbs. I have a 7 mile route to work at about 30 minutes so everything stays pretty cold, if it were longer I might use an insulated bag.