SRAM debuts an 11-36T range cassette in the 11sp series PG-1170. Marketed as a compliment to the CX-1 single chainring cyclocross drivetrain, the new 11-36T cassette gives a 13% lower gear than the earlier 11-32T 11sp cassette. In common with other 11sp road cassettes from SRAM (as well as Shimano), the cassette requires a hub with an 11sp cassette body, which is wider than what fits 8,9,10sp cassettes and had been an industry standard for more than two decades. However, it does not require the proprietary XD-driver like SRAM’s 10-42T 11sp mountain cassettes. Ostensibly, the 11-36T PG-1170 is only compatible with the CX-1 rear derailleur with the “X-Horizon” non-slanted parallelogram design. The design of the CX-1 rear derailleur excludes the use of multiple chainrings. However, I know that SRAM’s long cage “WiFli” road derailleurs can usually handle a 36T cog (depending on the dropout geometry of the bike frame), so I’m sure that you could incorporate the 11-36T item into a 2×11 drivetrain.
And that’s the thing about this cassette: 11-36T is kinda odd for cyclocross. On the vast majority of cyclocross courses, save perhaps for some local novelty events, there’s no need of a gear that low even if you only have a single chainring. Most people I know are running 38 to 42 tooth rings in 1×10 or 1×11 setups with either 11-28 or 11-32 cassettes. If the ground is either so soft or so steep as to require a lower gear, you’d almost certainly be better off running because your max width 33mm tyres wouldn’t be able to float or grip. I see this new cassette as being better within 1X drivetrains for those adventure rides or gravel grinders that see some intense climbing like Vicious Cycle’s Gran Fondo series in Central Washington. It could also make an awesome 1×11 setup for riding steep city streets like in Seattle or San Francisco. Or you could use the 11-36 with a compact double crankset to make a touring bike with a practical gearing. Touring bikes need that low end gearing which has in the past been achieved with the granny ring of a triple crank, but even Shimano seems to be phasing out triples in their road line-up. SRAM 11sp 11-36T cassette seems like less of a hotshot racer’s weapon and more of a tool for the everyday rider.
Some people might be wondering why SRAM introduced an 11-36T cassette for a CX-1 derailleur that seemingly does not have the capacity to handle a 36tooth cog. I can confirm that the CX-1 derailleur can handle 12-36 and 11-36 cassettes from some drivetrain experiments this past summer.