If you can fit all your ski gear in a carry-on, congratulations, you're a hero. For those of us who need more than one set of base layers for a week-long ski trip, Herschel's 71L Rolling Gear Bag delivers. Soft-sided walls expand to fit clothes, swimsuits, and extra shoes or sandals when the snow melts or Hawaii calls. Or if you're traveling in the shoulder season, the cavernous interior can hold bike helmets and ski boots so you can send the single-trek one day and hit the slopes the next.