Absolute Black is a company that is undoubtedly at the forefront of the design and manufacture of oval chainrings. Their tireless research and development coupled with state-of-the-art manufacturing capabilities have yielded some of the best oval rings, in terms of both performance and aesthetics, on the market today.
The musculature structure of human legs is such that maintaining even power on a round ring is extremely difficult, thus a round ring doesn’t transmit torque to the rear wheel as smoothly and effectively as an oval ring. Designed to function in better harmony with natural human physiology, oval chainrings work to minimize resistance in the “dead-spot” of the crank revolution where less power is produced while maximizing the part of the revolution where the most power is produced. This results in smoother power delivery to the rear wheel and improved ability to generate and maintain a constant cadence. Rear wheel traction is also improved as a result, most notably in mixed-terrain and off-road conditions. Another huge advantage is the reduction of “peak loads” on knee joints; less stress on the joints results in the ability for cyclists to ride at higher effort levels for longer, leading to higher average speeds. Oval rings also are effective in making climbs feel easier on the legs. After adjusting to oval rings, cyclists often feel their pedal stroke to be more “round” than it was with round rings.
These premium oval rings are beautifully machined from 7075 T aluminum and are designed specifically for use with Shimano Dura-Ace 9100 series, Ultegra 8000 series, and 105 R7000 series 4-bolt, 110 BCD cranksets. They can also be retrofitted onto Dura-Ace 9000 series and Ultegra 7000 series cranks. While the Absolute Black aesthetic bolt covers (available separately here) make the set-up look sharper no matter which crankset is used, they are especially recommended for the 9000/6800 retrofits. Available in black or grey (for the big ring, small rings are available in black only) to best match your model of Shimano crank, these rings come in 52, 50, 36, and 34 tooth counts. Absolute black recommends the following combinations for best performance: 52/36 and 50/34. They state that other combinations will work, but may result in slower shifting. As Shimano designed their cranks to have no more that a 16 tooth difference between rings, so combinations that have any more than this difference should be avoided. These rings are compatible with 10, 11, and 12 speed drivetrains. If only an oval small/inner ring is being installed, the Shimano factory chainring bolts can be used. If installing the oval outer/large ring long bolts are needed. These longer bolts are supplied with the Absolute Black bolt cover kits (available separately here); these kits improve aesthetics by perfectly blending the oval rings with 9100/8000 series Shimano cranks.
From the manufacturer:
ADVANTAGES OF ABSOLUTEBLACK ROAD OVAL CHAINRINGS:
One of a kind special oval shape that helps you climb easier and faster (Patent Pending)
-Over 15% stiffer than competitor’s rings due to thicker, 5mm construction
-Bespoke Absolute Black 6 point ramp and recess shifting design shifts better than any other brand and model of oval chainring
-Finest design that provides excellent strength to weight ratio
-You will not "feel" the oval shape while pedaling
-Your pedaling action will feel smoother
-Helps reduce stress on knees and helping your legs remain fresher for longer
-You will be able to maintain better cadence while climbing
-Reduces possibility of leg cramps
-You will reduce chainring/cog shifts by at least 15%
|Crank Compatibility||Shimano Dura-Ace 9100, R9120, R9150 & R9170 Di2 and Ultegra 8000, R8020, R8050 & 8070 Di2, 105- R7000, R7020, R7070. They can be retrofitted to all 9000 and 6800 series cranks|
|Drivetrain Compatibility||10, 11, and 12 speed drivetrains|