You’re railing that descent, nailing every line and feeling like a world champ, when suddenly you smash a wheel into a big square-edge rock. Quite literally, you can feel the air go out of the ride.

So, you've upgraded your mountain bike's clincher tires to tubeless, and now you figure you're all up-to-date and on the cutting edge, right? Well, perhaps not for much longer. German tire-maker ...