With a couple exceptions around the Bikerumor crew, we’ve become oval chainring converts. While Rotor’s been at it for quite a while, Absolute Black has been pushing the aftermarket harder than anyone. And not just by machining drool-worthy components, but by making sure they have as many crankset fitting options as possible. Fortunately for all of us, they keep finding ways to improve their product’s performance.
Or, in this case, bring that performance to new segments. The new Absoluteblack Oval Road Premium chainrings follow their narrow/wide mountain and cyclocross single rings, but take a whole new approach by offering smooth shifting across double chainrings for the road…
Absolute Black first started turning out ovals for the mountain bike crowd, but they say they’ve had demand from roadies. They presented their first road offerings at Eurobike in September and now have an expansive set of offerings. While oval rings have proven to improve performance by easing up the gear ratio during the weaker position in the pedal stroke so not to lose as much momentum when entering the stronger portion of the rotation, one of the drawbacks is front shifting. With 1X mountain bike systems it didn’t really matter -chain retention was more important- but on the road, you have two chainrings. And when they’re oval, the distance between the chainring and front derailleur doesn’t remain consistent, which can reducing shifting efficiency.
The new Absoluteblack Oval Road Premium chainrings feature an extensive, complex machining process unique to other systems on the market. Most chainrings have pinned “catch” points that grab the chain and carry it up a flat surface. Think of it as rock climbing up a sheer face.
Although those catch points are essential, Absoluteblack found a different way of making the chain move. Rather than abrupt pins and miniature ramps carved into the back of the ring, AB machined a ridged, sloped inside face with six angled grooves that help guide the chain upward and support along the way, even under load. Think of it as the difference between grabbing and shoving the chain up and encouraging it to smoothly move of its own accord and at an even speed. And because there’s six of those grooves, it should shift at any point in the crank’s rotation regardless of how the front derailleur is sitting in relation to the ring.
Another key to crisp, accurate shifting is to make sure the chainrings stay stiff. Though the machining is sexy as hell, it also creates a stiff, strong ring that holds its linear position even under heavy loads and eliminates as much material as possible to keep it light. AB says they’re 5mm thick, making them 15% stiffer than Rotor’s Qrings.
All of Absoluteblack’s chainrings’ timing are pre-clocked in the position they found to be most optimized in relation to the crankarm’s position. This takes any guesswork out of setup, and it saves weight. Outer rings come in Black, Racing Red, or Grey and retail for $124 (50T & 52T). Inner rings come in black only for $61.95 (34T & 36T). They’re available in Shimano’s asymmetric 110/4 bcd for cranks like Dura-Ace 9000, Ultegra 6800 and 105 5800.
Though not near as pretty (or visible), the small oval rings follow the same ovality as their big sisters. If you’re on the fence, Absoluteblack says oval rings shine best when climbing or correcting a less than perfect pedal stroke. It’s fine to mix ring shapes but they recommend starting with the small oval ring first and determine if a big ring is necessary. Some pro riders will do this to keep their sponsor’s big ring visible while taking advantage of the oval’s benefits.
Specs from Absoluteblack:
Size (Mass +/-1g): | 34T (31g), 36T (37g), 50T (120g), 52T (137g) (38&53T coming soon) |
Color | Black, Racing Red, Grey (inner ring in black only) |
Compatibility |
Shimano Dura-Ace 9000, Ultegra 6800, Shimano 105 5800, Tiagra 4700 |
BOLTS | For Outer chainring please order Long bolts. Use original bolts if changing Inner ring only. |
Material & Finish | CNC machined 7075 Txxx Aluminum with hard Type II anodizing |
Ovality |
Optimized to each size separately. 34T- 6.5% ; 36T- 11.4%, 50/52 – 10.3% ; Timing of 108 -109.5° after TDC (top dead center) – Ideal for road climbing. Patent Pending. |