First Impressions: absoluteBLACK Oval Chainring (Part-II)

In the first installment of GRAVELBIKE’s absoluteBLACK (aB) review, I covered aB’s 28T oval MTB chainring. Since then, the company began shipping their new oval CX chainrings. Available in conventional and direct-mount versions, absoluteBLACK’s CX rings feature the company’s Patent Pending narrow-wide tooth design. Because the conventional 5-bolt CX ring isn’t compatible with SRAM cranksets that have a hidden 5th bolt, I opted to test the direct-mount version. Over the past few weeks, I’ve logged 300-350 miles with the company’s 40T oval CX chainring on my Salsa Vaya gravel/commuter rig.

aB_40_chainring-min      aB-40-back-min

Installing the aB chainring on my SRAM Force 1 crankset couldn’t have been simpler. The entire process took less than 30 minutes, and required only two tools (a T25 torx wrench and 8 millimeter hex key). Like the stock SRAM chainring and spider, the absoluteBLACK oval ring has an offset profile for optimal chainline. By eliminating the separate spider, chainring, and five chainring bolts, the direct-mount aB ring saves 36 grams over the stock configuration (104 grams vs 140 grams). An added benefit of the direct-mount design is that there are fewer parts to maintain without any loss in performance.

For my testing, I paired the 40T absoluteBLACK oval chainring with SunRace’s 11-speed CSMX8 (11-40T) cassette. Running a new SRAM PC-1130 chain, the drivetrain felt as smooth–and ran as quietly–as the all-SRAM setup it replaced. Like the MTB chainring tested in Part-I, absoluteBLACK’s CX ring features a narrow-wide tooth profile for improved chain retention. The combination of the aB ring and SRAM’s clutch-style Force 1 rear derailleur proved to be extremely secure with no dropped chains to date.

While the absoluteBLACK CX and MTB chainrings may look similar, there are some subtle differences between the two. Both the MTB and CX chainrings’ ovality varies with size, but the CX rings employ a narrower range of ovality (10.2-12.1% vs 10.2-14.4%). The two designs also utilize different amounts of clocking, or timing. absoluteBLACK’s MTB rings are positioned 110.5-116.3° from top dead center (TDC), whereas CX rings are clocked 110.5-112.3° from TDC. Interestingly enough, I found that it took me longer to become accustomed to the oval CX ring compared to the MTB ring (despite the fact that I had already spent significant time on the latter).

aB 40 montage-min

The absoluteBLACK CX chainring shares the same traction moniker as the company’s other oval rings. If you’re wondering how a chainring can improve traction, you’re not alone (I asked that very same question when I started testing aB’s MTB chainring). It’s not like a chainring can magically alter your tires for better grip, right? What oval chainrings can do, though, is fine tune your pedal stroke and cadence. How does that improve traction, you ask? In my testing I found that the aB rings felt best when pushing a slightly higher gear at a lower cadence. That combination resulted in a smoother, more even pedal stroke, which reduced the likelihood of spinning out (gear too low) or bogging down (gear too high) in loose conditions. I couldn’t detect any difference in traction on paved or dirt roads, but I did feel more in-control when riding through deep gravel or snow (just don’t expect the aB ring to replace your knobbies or cross tires for technical terrain).

Where the absoluteBLACK oval ring had the biggest–and most unexpected–impact for me was climbing out of the saddle. Truth be told, I don’t have the best form when I’m standing on the pedals. As such, I tend to climb almost exclusively in the saddle. When riding with the aB chainring, however, I often found myself standing (and using bigger gears) where I would normally sit and spin. The absoluteBLACK CX ring may not have earned me any Strava KOMs, but I’m now much less reluctant to get out of the saddle on hills (which my backside certainly appreciates).

Is there a place for absoluteBLACK’s oval chainrings in road and gravel riding? I think so, but it depends on your pedaling style. If you’re the type of rider who always pedals at a very high cadence (and tends to favor easier gears), you may find that your pedal stroke is a little jerkier with the oval chainring (until you learn to use a slightly harder gear). On the other hand, if you don’t favor an ultra-high cadence, the absoluteBLACK oval chainring may actually help improve your pedal stroke by normalizing your power output (especially if you’re prone to pedaling squares). Either way, if you’re reluctant to give oval chainrings a try, absoluteBLACK will replace your oval ring with a round ring free-of-charge if you’re not happy with your purchase.

Disclosure: absoluteBLACK provided review samples for this article, but offered no other form of compensation in exchange for editorial coverage.