I have both kriega and Ventura for my bmw. If u can live with the metal rails of Ventura it’s much quicker Kriega is also excellent & u can add to main bag
Are you aware of these? https://sw-motech.co.uk/collections...80d-ballistic-nylon-50-litre-black-anthracite There's an even more sturdy (and bigger) one too. https://sw-motech.co.uk/collections...k-tail-bag-50-65-l-ballistic-nylon-black-grey
I have sw motech tank bags no issue but from my experience kriega or Ventura are easy to carry off the bike and can be transferred to different bikes