The SRAM RED PowerdomeX Cassette is the king of cassettes. It’s crazy strong and made from an entirely different mold. The eight middle cogs are all machined from one block of high-grade tool steel making them not only super strong but also super light—lighter than a titanium cassette. And between each cog is an elastomer that reduces vibration and noise so you can stealthily sneak up on people then zoom past them. Topped off with an aluminum large cog and a super durable finish the PowerdomeX is officially the coolest cassette on the planet. (And not just because of its name.) 10 speed. 135 grams (11-23).