Perhaps spurred by the popularity of Race Face’s CINCH 1x rings and other 3rd party, lighter chainrings, SRAM’s finally taking advantage of the weight savings to be had by moving to a direct mount chainring system. Their direct mount design is already in place, but until now it’s been used to hold the spider.
The new X-Sync drops the two piece design to save weight, and it’ll open up smaller tooth counts. You can now get an X-Sync chainring with just 26 teeth or up to 40 teeth, with all even increments in between accounted for. Aftermarket cranksets will all ship with the popular 32 tooth ring. They’re compatible with XX1, X01 and X1 1400 cranksets. And while you won’t be able to retrofit them to a standard XX
or X9 because of the spider interface with the chainrings, you will sort of be able to mount them to X0 (UPDATE: and X9!) crank arms from the past few years…
SRAM’s MTB PR man Duncan Riffle told us these are specifically designed for the chainring offset of their 1x crank arms, but that the direct mount interface will fit modern X0 and X9 crank arms. The only caveat is that you’ll need to pay attention to offset to ensure proper chain line and tire/frame clearance. We should have more specifics soon, but it’s worth checking into before purchasing. And SRAM has different offsets depending on whether you’re running GXP or BB30 cranks.
Like the originals, they’re fully CNC’d alloy, engineered in Germany and use SRAM’s X-Sync wide/narrow tooth profiles to keep the chain in place and help shed mud. They’ll be available for both GXP and BB30 spindle versions. Weight savings over the spidered versions range from about 25 to 50 grams, here’s the claimed weights:
Perhaps the only tradeoff is that you’ll have to remove your driveside crank arm to change the rings, something you don’t need to do with the two-piece design. So, if you’re constantly changing chainrings to suit conditions, might be worth hanging on to your 2-piece setup.
The 30, 32 and 34 tooth counts will all be available this month (December, 2014). All other sizes will follow in April 2015. Retail is $99 / €88 / £75.