the nice thing about these is you can expand them... they had WAY more than enough room... in the photo with my bike I've got a tent, sleeping bag, sleeping pad and rain gear... strapped to the top of the bags... if your not camping you can rid all of that. also I had TONS of clothes... way more than I'd need on any other trip... I have 4 shirts away... had more than enough for any motorcycle trip... I packed like it was a vacation and not a motorcycle trip.
you shouldn't need any larger bags unless your going for 2 or 3 weeks camping and bring'n your own food... then... buy a diffrent bike
I loved the bags... the rain covers were the only issue... but never had wet gear when using them... when USING them...
it rained one morning so hard it soaked everything in the 30 mins it took for me to tear down and pack everything up and cover my bags... lucky the next day was at Rae's and I could air dry everything in the FL heat