Hey Simmo... you can get after-market pannier bags for both your L & R panniers... a.k.a. pannier liner bags... they're a zippered heavy nylon/canvas carryalls that're tailored to fit inside each pannier... we have found ours an excellent piece of kit and you can pack quite a lot into them... we done a number of 2-up long weekend trips and found that these bags (mine and hers) plus the topbox and maybe a tankbag, gave us plenty of packing space... click on Search above, put in pannier bags, and go from there... cheers, John & Kate.