I use this one. I carry 1 litre of gas, tire fixing tools , a litre of water and some other small stuff in the side pockets. the main compartment is still large enough to carry 2 one galon milk bottles and bunch of other groceries. When I go to work I carry my laptop in a backpack in my main compartment. One time I put 3 13 inch and one 15 inch mac book pros in it.
Its much better than carrying a backpack because when I carry a backpack in a 30-35C (95F) weather it blocks the air flow through my jacket and the back armor and it becomes really hot.
Keep in mind the price on the site is in canadian dollars.
https://gearscanada.com/products/nav...cycle-tail-bag