SRAM OG-1090 Red Cassette $278.95
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 teeth function as gateways that allow the chain to shift fluidly no matter what kind of stress you're putting the bike under. And, they allow SRAM to save weight without having to resort to easily-worn titanium cogs.
The SRAM OG-1090 Black Cassette fits any Shimano style 9/10-speed freehub body, and it's compatible with any 10-speed chain: SRAM, Shimano, or Wippermann's S-series chains. What SRAM suggests, of course, is that you use one of their 10-speed PC-1000 series chains for optimal shifting. Given its lightness, the PC-1090R is the chain of choice for the Red gruppo. It includes an anodized, laser-etched aluminum lockring.
The 11/23 includes: 11,12,13,14,15,16,17,19,21,23
The 11/26 includes: 11,12,13,14,15,17,19,21,23,26
The 11/28 includes: 11,12,13,14,15,17,19,22,25,28
- CNC‘d Cro-Moly steel construction is lightweight and extremely durable
- 35% harder than titanium for durability
- OpenGlide technology provides quick, precise shifting