Did I mention that I'd been on holiday in the Netherlands, camping with bikes and that I'd had to honour of carting everyone's stuff in a big bag on a Y frame? Did I?
It was great but the pouring rain on the way home highlighted one shortcoming of the arrangement. The big bag wasn't waterproof. Of course, I knew that before I went. You couldn't expect much of a 140l bag that cost £17 from Amazon. And it was on the way home so no one cared about stuff getting wet. It was all destined for the washing machine.
Anyway, I've got (at least I had) a big bit of waterproofed canvas so it was a relatively easy task to run up a cover for it, with lots of room for expansion for even bigger loads.
More photos here.