... .alloy brake. 2.450g/pc 3.strong. 4.700c road Item: 700c road bike carbon rims with alloy brake, strong!!!!Depth: 38mmVersion ... and stiffness.4.about basalt braking surface.Adopting special anti-high temperature basalt resin. when riding, especially for a long time ... bike activity. Luckily, basalt, a good material to resist the high temperature, a good solution in terms of this problem.5 ...