I've got the large Rickshaw Zero Messenger and it's probably about the size you need. I also take a change of clothes and a small selection of tools to work with me each day and have some room to spare. Then, when I do a shop it has plenty of room for all the essentials.
It costs extra for a shoulder strap pad and the cross chest stabilising strap (essentials), but it's still cheap compared to other bags on the list here and has shown no signs of wear and tear since I started using it.
I got it from Urban Hunters but it doesn't look like they stock them anymore which is a shame
I've got the large Rickshaw Zero Messenger and it's probably about the size you need. I also take a change of clothes and a small selection of tools to work with me each day and have some room to spare. Then, when I do a shop it has plenty of room for all the essentials.
It costs extra for a shoulder strap pad and the cross chest stabilising strap (essentials), but it's still cheap compared to other bags on the list here and has shown no signs of wear and tear since I started using it.
I got it from Urban Hunters but it doesn't look like they stock them anymore which is a shame