SRAM OG-1090 Red Cassette
Black is back. And on the SRAM OG-1090 Black Cassette, the back is anodized black instead of Red. Otherwise, this is the same Red cassette that caused such a huge industry buzz when it was introduced. It's made using "PowerDome" technology, meaning that the top 8 cogs are CNC machined from a single piece of chromoly steel. If you've ever pulled a Record cassette off your training wheel to install it on your race wheel and had it spill onto the ground into literally 20 pieces -- 10 cogs, 10 spacers -- you understand the structural differences here with Red. PowerDome is basically a two-step process. First, a block of chromoly steel is milled into, yes, a dome, with the cog teeth then CNC-machined into the dome. SRAM states that one cassette requires a full hour of milling and machining before it's done. Next, the steel gets a nickel finish to give it immense hardness. How hard? SRAM's testing indicates that it's 35% harder than titanium -- which directly impacts your wallet, since harder cassette cogs are more durable cogs. They wear out at a slower rate, so you end up replacing your cassette less often. This steel 8-cog block then gets paired with two additional "floating" cogs to make 10 cogs total. Beyond durability, PowerDome construction lends the OG-1090 two other benefits: (1) Lightness. The 11/23 weighs a scant 155g. The 11/26 is 166g. By comparison, a Steel/Ti Record cassette weighs 188g, a Dura-Ace cassette weighs 170g, and a Force-quality OG-1070 cassette weighs 220g. (2) Stiffness. SRAM testing indicates that their one-piece cassette dome makes the OG-1090 15% stiffer than any other cassette. We can especially see the upside when you're in your climbing cogs, wrapping a lot of chain and exerting no small amount of torque. The OG-1090 takes advantage of the same OpenGlide technology SRAM unveiled with the OG-1070 cassette. The first time you set eyes on the OG-1090 you'll likely see that one tooth is missing from each of the 5 high cogs. These missing t...