Initially skeptical of embracing any shape besides round having suffered through knee pain in the age of Shimano Biopace, I have found myself ordering additional Absolute Black or should I say, Absolute Green and Absolute Red chainrings for multiple bikes. Spending considerable time in the saddle mashing up epic climbs such as Dr. Park in Crested Butte, Chimney Gulch to Apex, or the Arizona Trail in Flagstaff, my riding style finds little love with single front chainring configurations and their inherent lack of smaller incremental ratios, so my test bike was rocking out 2×10 (26t,36t).
After my initial 30 day test period, I’ve been impressed with the acceleration and increased torque in comparison with their circular cousins at slower RPMs where the ovular shape seems to minimize output force in my 3 o’clock dead spot to get my wagon wheels rolling. Pedaling on the road in the 36t or staying in the smaller 26t ring on faster segments induces choppy pedaling, albeit having an imbalance between my two legs following multiple knee scopes might be accentuating this perceived chop. My right knee with patellar cartilage defects is noticeably happier and less strained accelerating 29” wagon wheels through undulating technical terrain at lower RPMs using the Absolute Blacks. For riders entering the 75 RPM range and over on a consistent basis, any benefits from minimizing the forces required to muscle through the dead spots, may be insignificant. In my opinion, these rings deliver a unique performance touch for mashers and grinders that is far from subtle and might even offer an edge on technical climbs, rock gardens, or clearing a tricky log pile.
Mechanically minded riders might express immediate concerns regarding shifting, chain suck, chain tension, crank compatibility, and smooth meshing between the links and teeth. In my case, the 64/104 Absolute Rings mounted directly to my Lightning Cranks 64/104 BCD Spider without issue besides shortening the bolts for the large ring. My assumption is Absolute chose to drill deeper insets to ensure the bolts are tucked away thereby avoiding chain snag. The only important installation side note is to make extra certain the small imprinted circle on the small ring and triangle tab on the larger ring align with the crank arm otherwise the oval will not align to your dead spot.
Shifting was actually smoother and more precise than my previous ramped and pinned KCNC Chainrings and chain tension proved to be an unnecessary concern. Since Loctite and similar cyanoacrylate products tend to breakdown in the blazing heat of the desert Southwest, I am in the habit of using a bit of pipe joining compound to seal and lock threads. Whether these chainrings distribute force unevenly is a debate better left to mechanical engineers with the time to complete a Finite Element Analysis, but during the first week of testing, the outer bolts continually loosened regardless of initial torque. Eventually, I placed fine lock-washers under the bolt heads and added a drop of blue Loctite. 400 miles later, shifting is still spot on and the loosening bolt issue has been resolved without further tightening. The teeth are still free of burrs and perfectly intact even after clawing over logs.
While certainly not an innovation on par with tubeless tires, disc brakes, wider bars, shorter stems, thru-axles, or current suspension forks, oval chainrings complement mashing and muscling larger wheels through the ugliest terrains. Unfortunately to date, there appears to be few biomechanical studies establishing the degree of ovularization required to provide the best mechanical advantage, so keywords such as “optimized” should be dismissed in favor of “possibly improved” or “could offer an advantage.” Without evidence or double blind studies to back up adopting ovular rings, opinions and reviews are purely subjective and are sure to fall in-line with the endless marketing hype surrounding 29ers, 27.5+, fat bikes, boost, and other innovations touted as being the holy grail for launching weekend warriors to the podium, therefore I would not expect any concrete or final conclusions to hit the bike magazines anytime soon.