What is it?
The PR claim is that by using oval shaped (rather than round) chainrings, pedaling smoothness and overall efficiency is improved because the impact of the dead spot in your pedal stroke is minimized. Various iterations of the concept have been around for years, but it has never gained widespread acceptance. However, some pro riders such as reigning Tour de France champ Chris Froome and the now-retired Bradley Wiggins have used oval rings (from a different manufacturer) to great success, and many amateur riders swear by their effectiveness.
Six machined up-shift ramps on the backside of these rings help keep shifting relatively crisp and smooth.
AbsoluteBLACK promotes its oval chainrings as being among the best due to the refinement of design and detail via use of top materials and state-of-the-art CNC milling machines. The company makes a huge variety of oval rings for both mountain and road bikes. RoadBikeReview tested a 52-36 set-up on an 11-speed Shimano Ultegra drivetrain. Test ring weights were 140 grams for the 52t and 35 grams for the 36t (175 grams total). The standard Ultegra set-up that was removed weighed 148 grams total, but had a smaller tooth count (33 grams for the 34t inner ring; 115 grams for the 50t outer).
- Some improvement on very steep climbs
- Subtle smoothing of pedal stroke
- Options for most bike set-ups
- Durable aluminum construction
- Potential placebo effect
- Chris Froome swears by oval rings
- The look (if that's your thing)
- Slight shifting degradation
- Some impact to "feel" of pedal stroke
- The look (if that's not your thing)
- Break up of drivetrain system
- Slight weight penalty
- Rings can collect road gunk and grime
- Lack of concrete science behind claims
Did these oval chainrings make a huge difference in my riding experience? Probably not. But I did manage to PR a few short steep climbs while they were mounted on my road bike. Current level of fitness certainly played some role in those efforts. (I was going good then.) But I also believe that the subtle dead spot smoothing helped increase efficiency just a fraction, meaning my legs didn't load up with lactate acid quite as quickly. It also took very little time to get used to the feel, which is a frequent complaint among oval ring detractors. When I first made the switch, things felt a little off. But within a handful of rides all seemed normal again.
The lattice-pattern on the front of the rings helps keep weight low, but creates a trap for grit and grime.
It's also worth noting that I stepped up from a round 50-34 set-up to an oval 52-36, yet did not feel over-geared on steep climbs because the oval 36t ring essentially mimics the feel of a 34t when you're in the weaker portion of your pedal stroke. Conversely the 52t big ring meant I was less likely to get spun out during descents. But a standard 52t would still be preferred to maintain speed going downhill.
Other knocks against the set-up include the look, which is a little loud for my tastes, and shifting feel. I never had issues with dropping the chain or anything like that. But even with the absoluteBLACK's six machined up-shift ramps, changing gears was not as crisp as with the standard round-ring Shimano Ultegra set-up. Was it a deal breaker? No. Was it noticeable? Yes.
Bottom line, I believe the ideal application for this set-up is for the rider who does a lot of low-cadence climbing or on a 1x mountain bike drivetrain, where front derailleur shifting is not an issue, and steep, low cadence climbing is frequent. I also think that if you're at all curious, they're worth trying for yourself. The barrier to entry is not that high, and you may find that you love the results.
Rating: 3.5 out of 5
Price: $126 for 52t; $62 for 36t
More Info: absoluteblack.cc and check out the promotional video below.
[vimeo width="610" height="343"]https://vimeo.com/152897512[/vimeo]
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