Qbag Tail Bag 5 Motorcycle Luggage | In-depth Look and Review [4k] 

Brilliant bag. I got one for the back of my cb125f. Perfect for fitting the work laptop, my lunch, my D lock, puncture kit and still have space to spare if you pop out the sides which I don't need. That's the main reason I bought it, versatility. That first black cover in the side you referenced was actually an inner bag for putting stuff into. Just like one of those cheap drawstring types. Perfect for loose items or if you stop to buy something. The yellow one is for keeping the wet and crud off. I've used mine a good few months over winter. Only used the waterproof cover a couple of times but it never got wet inside even without! I love it. The only thing for me is those secure grips. Is rather they were the plastic buckets in case they damage paintwork etc as they are solid. They do take a little time to hitch/unhitch if you keep stuff under the seat but heyho.

Can't wait to see more on this ZX this summer! Nice bag!

Would like to see a pair of trainers and what you would like to take for a weekends put in the bag for more clarity. Maybe a 30 Litre bag might be better for a weekend

I got one and put my trainers and waterproofs in. I was bambosled by the strap system though. I'm sure i haven't done it right.