Arkel's bike bag.

This bike bag, made of lightweight PU coated 420 deniers nylon is designed to carry your bike in public transportation systems (and particularly the train in Europe!). From the airplane to the bus, from the train to the taxi, you can handily carry your bicycle with the integrated shoulder strap. As in many instances you may have to fold the bike bag and carry it along until your next public transport hop and possibly throughout your whole bike tour, we’ve favored lightness over ruggedness. The bicycle bag folds into a small pack that you can carry inside your panniers or strapped on top of your bike rack.