Carbon braking surfaces are continuously evolving, with new innovations every year promising to approach, meet, or even surpass the braking on alloy rims. But with the Mavic Cosmic Pro Carbon Exalith Clincher Wheelset, braking isn't an issue. Neither are weight or aerodynamics. Obviously, they aren't going to be as light as the leading 50mm all carbon rims, but they're also 13 less expensive, only weigh about 100g more, and feature Mavic's Exalith II brake track. There're a few very good reasons to go with full carbon rims, but the Exalith II brake track on the Cosmic Pro Carbon means that it avoids all of the potential downfalls of carbon braking. We should note that by downfalls, we literally mean falling down, as in crashing due to unresponsive braking or calamitous wheel failures due to heat accumulation. When carbon hits a certain temperature, known as the glass transition point, it violently deforms, briefly losing its stiff, rigid structure and turning rubbery. Since heat builds up while braking on long, steep descents, this tends to happen while going downhill very fast an inopportune time, to say the least. The Exalith II brake tracks eliminate this issue. They're alloy, so they'll hold up to braking heat, and the Exalith II treatment means that they hit a level of stopping confidence in wet and dry conditions that carbon can only dream of. We've seen some impressive carbon brake tracks over the past few years, but those are only now beginning to rival standard alloy braking, and Exalith II is a claimed 18% more effective than alloy tracks, meaning that it's far and away the leader in braking confidence. It also looks pretty damned cool, and it won't ruin a stealth machine with a bright strip of silver. If the slightly lower weight and added stiffness of full carbon are worth the trade off, then we say go for it however, if you're after a wheel that you can use every day for every type of riding, then the Cosmic Pro Carbon Exalith's strong bra...