Whether you ride Campagnolo, Shimano, or SRAM, Ratio Technology has the one CNC-machined 1x chainring to rule ALL 12-speed AND 13-speed setups. Using their own unique narrow-wide tooth profile, these rings work with all the latest drivetrains. From Eagle to FlatTop to Ekar. And their spiderless shaping will both cut through the wind and make your drivetrain easier to keep clean…
Ratio Universal fit 12/13sp Direct Mount chainrings
Ratio already had standard 110BCD chainrings. And the latest 40-44T versions of those already teased universal 12sp & 13sp fit. But now the company that revived a lot of your old mechanical shifters & derailleurs, is giving you a better Direct Mount update as well.
Developed to work with all of the cranks that use SRAM’s modular DM splines, Ratio machines the new rings with both 3-bolt & 8-bolt attachments available. That includes compatibility for all of SRAM’s modern DM road cranks with 45mm chainline. Plus many more from companies like Cane Creek, Easton, e13, Praxis, RaceFace, etc.
Shimano HG+ 12, SRAM Eagle 12, SRAM T-Type 12 & Campy 13… but how?
It wasn’t a big surprise when Campagnolo jumped to 13-speeds that they would need new chains & chainrings. But SRAM was a bit more sneaky. Redesigning the still-12-speed road FlatTop and then Transmission chain profiles to necessitate completely new chainring shapes. But Felix Barker cracked the code and wrote a Master’s thesis project about it at the University of Cambridge.
Working at Ratio, Felix created an all-new asymmetric tooth shape. With a forward-facing profile that drives the chain, sharing the chain load across multiple different rollers in a calculated balance of higher load strength and longer wear. Then, on their more hooked trailing edge, Ratio creates better retention to resist the wave action of a loose chain when freewheeling over rough terrain. Which we know still happens even with a clutched derailleur.
And they do that all while fitting around the various thin internal shapes of all the latest 12 & 13-speed chains out there today.
The new Ratio Direct Mount chainrings are reasonably light at 105g for a 40T (claimed) but not ultralight. So why did they go for an aero design vs. a presumably lighter spider configuration?
Ratio director Tom Simpson explained to us that is was primarily a structural choice. Of course the rings need to account for the uneven loading of a cyclist as we pedal. (Sometimes more squares than circles.) But also to account for smashing rings on rocks. And no one wants to taco a chainring. And “going without holes was much more about these failure modes than it was about aerodynamics, although it’s a nice bonus that they’re easier to clean and look cool!“
The DM rings are CNC-machined in the UK’s Lakes District from 7075 aluminum. At their thinnest just 1mm thick, with the structural ribs coming up to 3.5mm thick.
Ratio Direct Mount chainrings – Pricing, availability & options
The new Ratio Direct Mount chainrings sell for £70 in sizes 34-44T. And come in any color you want, as long as it’s black – with silver teeth. That’s about $73 / 67€ at current exchange rates.
All sizes are available now in both 3-bolt (with 7mm offset) and 8-bolt (8.5mm offset) spline patterns to fit a wide range of SRAM compatible DM cranksets. Claimed weights per DM ring are: 34t 75g, 36t 85g, 38t 90g, 40t 105g, 42t 110g, 44t 120g.
Get them now direct from Ratio.