I'm about to retire my Manhattan Portage bag that's served me well for 7 years.
So I would like to know what you STW commuters are using to lug stuff to and fro. The current bag is Ok but on a road bike isn't very stable when fully loaded.
It will need to accommodate the tools, tubes, clothes, shoes, waterproofs, on average about 8kg.
As a French friend used to say 'My hears are open" and I look forward to your pearls of wisdom.