When you think about the performance advantages that tubular road and cyclocross tires provide smoother ride, less rolling resistance, the ability to run lower pressures safely, the lower weight than tire and tube combos, and more it makes sense that they're massively popular under the pros. Bring those advantages into the world of mountain bikes, however, via the wheel masters at SRAM, and you have something truly ground breaking: the SRAM XX Rise Carbon Tubular Wheelset, a set ready to dissect the competition, one climb, sprint, and podium at a time. Starting with the rim, SRAM didn't simply beef up an existing cyclocross or road tubular design, although they did consult the rim geniuses over at Zipp for input. Ultimately, SRAM developed a competition focused XC race rim with unidirectional carbon fiber and a special resin designed to both mitigate impacts and vibrations to improve ride quality, while also making the rim more durable overall. Not needing to integrate bead grabbing sidewalls into the rim saved enormous weight while boosting the rim's structural integrity. It's light enough to fly but tough enough to take a beating on par with the toughest XC wheelsets out there, so riders can scratch durability off their list of concerns. The rim then gets laced with 24 Sapim CX Ray straight pull spokes in a two cross pattern, front and rear, to boost the wheels' stiffness and again enhance their toughness. Moving down into the hub, we find SRAM's Speedball ceramic bearings keeping rolling action silky smooth and fast. The rear hub employs the company's new Double Time ratchet mechanism, kicking up the hub's engagement points from an industry average around 24 30 up to 52. Why does this matter' When you resume pedaling after coasting, the more points of engagement in the rear hub, the shorter distance you have to move the pedals before you are actually pushing the bike forward again, as opposed to just dead spinning. This makes the wheel far more respons...