anybody recc one ,?i need to replace my one i use for work so it has to b capable of holding a flask ,box , gym kit and gen bike stuff ,iv got a few ones that are just too small ,im not sure about the messenger bag thing as iv never rode with one ,so an old style double shoulder strap rucksack prob ,not really fancy as its gona get a bit of wear and tear ,so hard wearing is best ,so any ideas or somebody selling one