Over the past two years, OneUp Components has been releasing narrow-wide chainrings for just about every imaginable bolt pattern and modern crankset, including the latest Shimano XT and XTR’s asymmetric spider, SRAM direct mount and standard 104BCD and a versatile 94/96BCD design.
Now, they’ve ported all of those designs, plus a brand new Race Face CINCH direct mount design, to an ovalized chainring called the Traction Ring. It’s clocked at 115º with 12% ovality, a position and design they came to after testing for 10 months.
Mirroring the claims made by Absolute Black and others, the new non-round chainrings claim to improve mountain bike traction over standard round rings. Having ridden several oval rings on my own mountain bikes, I’ll back up that statement and as OneUp suggests, the next time you need to replace that chainring, consider one of their many new oval options…
The Traction Rings are all 32-tooth designs, but they say they feel like a 34T where you’re strongest and a 30T in the dead zone. The improved traction comes from smoothing out the torque on the pedals by giving you a bigger gear where you’re stronger and smaller one where you’re weaker. Before the comments light up with all the reasons why oval rings don’t work or how the physics of what is typed here is all wrong, just try them. OneUp makes no claims as to improved power output, leaving it at improved traction with zero downsides. Oh, and they also want you to know it’s 90º offset from Shimano’s BioPace rings of yore.
All are machined from 7075AL with reinforced wide teeth to improve durability when run without a bash ring/guard, and all set up with a 49mm chainline, which puts the chain slightly closer to the larger cog for quieter, smoother performance.
Shown above and directly below are the XTR M9000 and XT M8000 replacement chainrings. Both include the necessary shims or replacement bolts to make them directly compatible with the new cranksets and their existing hardware.
The XTR gets a matching gray tone, and the XT is black with a bit more machining. The XTR rings are threaded, so the bolts tighten directly into them. The XT rings pass the bolts through to thread into the spider, so they are not interchangeable.
Actual weights for these two are 56g (XT) and 57g (XTR).
The SRAM Direct Mount fits any modern SRAM 10/11 speed GXP and long-spindle BB30 cranksets with the removable spider. Long spindle BB30 models include X0/X9 Cranks with 38/24, 36/22 and 34/22 ring combos.
The three bolt holes ensure proper alignment when installing on the crankset.
The new Race Face CINCH direct mount rings have a very similar design but with a small hole to align with the center of the crank arm.
Weights are 62g (Race Face) and 60g (SRAM).
The 104BCD oval ring has built in shims and threaded holes, making it as easy as possible to install and go ride.
The 94/96BCD rings use the same slotted bolt holes as the round versions, allowing them to fit both SRAM and Shimano cranksets with symmetrical bolt circle patterns. They obviously can’t have threaded holes, but they do include shims to allow to reuse the stock bolts from your crankset.
The 104BCD ring is 48g, and the 94/96BCD ring is 50g with shims.
I’ve got them installed, but haven’t had a chance to ride it yet. Installation of the SRAM DM ring was quick and easy on an older XO GXP crankset. This bike is set up with a 10speed drivetrain running OneUp’s 42T cassette adapters, too.
The rings use OneUp’s existing narrow-wide design with “crud chamfers” to help dirt and mud slice off the chain and fall away rather than getting packed up and decreasing the chain’s grip on the teeth.
Of course, they’ll work wonderfully with OneUp’s oversized cog and 16T cassette adapters.
Available in black only for now (except the XTR one), all retail for $52 USD. Available now.
