Latex stretches roughly 7 to 8 times its original size where butyl manages only about 1.5 times, and that elasticity is the whole reason to run a tube like the Challenge Latex Tube. The thinner, suppler material conforms to the tire as it flexes through corners and over rough pavement, which lowers rolling resistance and takes the edge off road buzz. Challenge produces the only seamless one-piece latex tube on the market, so there's no pucker or bump where a seam would normally join, and no out-of-round spot to unbalance the wheel as it spins.

You've got two widths to choose from, covering 700x24-32mm and 700x33-42mm tires, both running a 60mm removable-core Presta valve so adding sealant or fitting an extender for deep-section rims is straightforward. The removable core lets you run inline or external extenders as your wheels change. Because latex is so much more elastic than a stiffer butyl tube, it tends to stretch and wrap around a sharp object rather than getting punctured by it, and the lighter material shaves rotational weight at the same time.

Two things to know before you buy. Latex is porous and loses air faster than butyl, so plan on topping off pressure before every ride rather than every few days. And skip these on rim-brake carbon clinchers — the braking surface builds enough heat to cause latex to fail. Aluminum rim-brake wheels and any disc-brake setup are fine, which is where most riders run them anyway.... Read More