A dropped chain you can fix with your hands, but a flat with no way to reinflate ends the ride. The Gem from Crankbrothers is the Black Midnight Edition of the brand's short dual-piston hand pump, built to live in a bottle cage or jersey pocket and get you back to pressure without a shop stop. It runs a hybrid alloy/composite construction that keeps the whole thing around 128 grams and roughly 176mm long, so it disappears in a pack until the moment you need it.

What separates the Gem from a basic mini pump is the dual-stage air switch. Under 40 psi, you leave it in high-volume mode and move a lot of air per stroke, which is how you get a flat mountain or gravel tire off the ground quickly. Once resistance builds, you rotate the switch to high-pressure mode, and the effort per stroke drops even as the number climbs. That's the difference between fighting a tiny pump the whole way up and actually reaching road pressure without your forearm giving out.

The convertible head reads both Presta and Schrader without an adapter to lose, so the same pump covers your road bike, your mountain bike, and a kid's bike with a Schrader tube. If you're the person who ends up helping other riders at the trailhead or on a group ride, that dual compatibility matters more than it sounds.... Read More