[Donaldomoto]

Well, technically the BMW 28 litre top-case can hold a full-face full-size hemet.... but as a commuter I largely use my top case to carry my wet-weather gear and other bits and pieces. And when that stuff is in there, there's no way you can fit the helmet too. If you want to carry helmet plus wet weather gear etc., I suggest you go for a bigger volume unit from Shad, Givi etc??? I had a beautiful Givi V47 (47 litre) top-case on a previous bike and it could fit the lot (wet-weather gear, hemet, jacket)