AbsoluteBlack Winter oval road bike chainring long term review

AbsoluteBlack has been making intricately machined oval chainrings for some time, and they’re beautiful. They’re also expensive, so this past spring, they came out with the Winter set for road. Winter being another way of saying “off season”, or “training” rings since they’re a bit heavier and lose the machining on the outer face of the large chainring. That makes them more affordable, but they don’t have the chiseled look of their Premium Oval chainrings, tested here.

The shaping isn’t just cosmetic or to save weight, it also boosts strength and stiffness, aided by their 5mm thickness. Which works, these are incredibly stiff. They also happen to shift smoothly and quickly, and even with a moderate ovalization, slot into modern drivetrains with minimal or no issues…

AbsoluteBlack Winter oval road bike chainring actual weights

I tested a 50/34 combo built for Shimano’s current asymmetric 4-bolt pattern. The large chainring comes in at 122g, the small at 31g and the nut-and-bolt package at 8g. For comparison, the Winter 50T chainring comes in at a claimed 156g.

AbsoluteBlack Winter oval road bike chainring actual weights

They were mounted on an Ultegra crankset, whose stock chainrings weighed in at 113g, 33g and bolts at 5g. Shimano’s chainring bolts thread directly into the large chainring. Total weight gain from the switch: 10 grams.

AbsoluteBlack Winter oval road bike chainring long term review

Front side machining is left showing the ridges, unpolished, and there are no covers to morph the shape into Shimano’s arms. Regardless of these missing finishing touches, they blended into the cranks well enough for my tastes. Over a few weeks of testing, the bolts never came loose, which bodes well for their long term use.

AbsoluteBlack Winter oval road bike chainring long term review

The backside gets a total of six upshift ramps, also machined. As in, not forged or stamped.

AbsoluteBlack Winter oval road bike chainring long term review

If you’ve made it this far, you’re either already an oval chainring convert, or your oval curious. For the latter, here’s the elevator pitch: They maximize your leverage in the most powerful part of your pedal stroke, and make it easier where you’re weakest. The net effect is that your pedal stroke feels smoother, more circular. The pic above shows how the tallest part of the chainring, which acts like a higher tooth count, is pulling the chain where you’re putting the most force downward on the pedals.

AbsoluteBlack Winter oval road bike chainring long term review

As you come into or exit your power zone, the effective diameter is lower, making it easier. The actual ovalization is only 10.3%, so it looks and sounds more dramatic than it really is, but it works. AbsoluteBlack doesn’t offer adjustable angles like Rotor, instead settling on a position that they’ve tested to be generally very efficient for the average rider.

AbsoluteBlack Winter oval road bike chainring long term review

Our test rings came with one caveat – they don’t recommend riding the smallest three cogs while in the small chainring. Why? Because with the taller part of the oval sticking out further, it could rub or catch the chain inadvertently. The pics above show it in both extremes (click to enlarge). Fortunately, it ended up with clearance throughout the entire range of the cassette on our Parlee Chebacco test bike.

AbsoluteBlack Winter oval road bike chainring long term review

I raised the front derailleur slightly so it would clear the large chainring in its high point rolled past the cage. And with that, all adjustments necessary to run these oval rings in place of the stock round ones was done. Granted, Di2 was a bit easier than with a mechanical system, but still.

AbsoluteBlack Winter oval road bike chainring long term review

With that caveat in mind, or perhaps because of it, the smooth shifting seemed all the more impressive. Up and down shifting was on par with the Ultegra rings these replaced, which is about as high a praise I can give them. I degreased the chain and gave it a fresh coat of Smoove chain lube prior to swapping the rings, and with that the entire drivetrain ran quietly. Under stand-up-and-mash-the-pedals power, they didn’t seem to flex, as measured visually and by the lack of rubbing the front derailleur cage. Oval or not, AB’s Premium chainrings live up to the top level billing.

AbsoluteBlack Winter oval road bike chainring long term review

As for ovality in general, I’m a fan. AB’s founder Marcin says average riders are going to notice the biggest difference (“improvement” in his words), much more so than “pro” riders that have fine tuned their pedal stroke. I’m not sure what that says about me as a rider, but I like them, particularly on my mountain bike with a 1x setup, but here, too. On a mountain bike, the biggest gains to be had seem to be with improved traction thanks to a smoother, more consistent application of power. To test that on the road, I found an incredibly steep concrete service road (above, on the left, not the dirt one) and rode up it. Standing and grinding up the 18% grade at about 3mph, I noticed that rather than bobbing up and down on the pedals. My body was floating in the same space as my legs cranked underneath. And the bike didn’t lurch forward like it usually does on such steeps, it just kinda maintained a steadier forward momentum. Sustained seated climbing up less steep but longer ascents also seemed smoother and more efficient. Overall recommendation: Worth it.

The Premium Oval chainrings for road retail for $124 for 50/52 large rings, and $61.95 for 34/36/38 small rings. They’re available in black, red and racing gray (tested), for Shimano 4-arm asymmetric cranks only as of this review. Five-bolt 110bcd and 130bcd options are coming soon.



  1. Is this any different than Biopace which was all the rage in the late 80’s?

    Seems to me science should be able to validate this one way or the other fairly easy.

    Maybe not?

    • Yes, it is different. Biopace wasn’t exactly oval, it was computer calculated after intensive research. They stopped doing it because there wasn’t measurable effect in reality despite subjective feelings.

  2. The ring thats most useful is the small one so you can potentially just het that for 60usd. Makes it decent.
    The article mention possible issues with the 3 smallest cog on the small ring but i suspect its on the big ring. The smaller the ring the less pronounced the ovality and chain displacement

    • Bob – it is a potential clearance problem with the three smallest cogs when the chain is on the small chainring up front in that the chain could make contact with the large chainring. It didn’t happen for me, but AbsoluteBlack doesn’t recommend riding in those combinations with these rings as a safeguard. Some of it will depend on chainstay length, BB width/placement in relation to the dropouts, etc, particularly for disc brake equipped bikes since they tend to have slightly wider rear axle spacing, which pushes the driveside outboard by 2.5mm compared to a rim brake bike. Best advice? Try it in the work stand and see what works for your bike before jamming on it outside.

  3. I’m wondering how a 34T small oval ring work? How much ovality is there. (Okay, that’s not actually a word, but I don’t think eccentricity is quite right either) I thought the Shimano asymmetric cranks used a 110mm BCD, which fits a 34T at the smallest. I wouldn’t think the asymmetry would let you fit a smaller chainring since the asymmetry of the cranks don’t line up with the asymmetry of the oval ring. Possibly explanations:
    -Shimano cranks can fit smaller than 34T/BCD ?
    -The small ring isn’t *that much* of an oval that it won’t fit?
    -The asymmetry of the spider lines up with the oval enough that it fits?
    Obviously it does fit, so I’m not questioning that it will work, just wondering how.

    • In Rotor’s “position 3”, which Absolute Black has copied in their oval rings, the crank arm going down in it’s revolution is in about 20° angle relative to a horizontal line drawn at the bottom bracket height when the effective diameter reaches it’s peak. As Shimano’s four spider arms are approximately at 75° angles relative to the crank arm, the wider parts of the oval are quite compatible with the spider arms. And as can be seen at the the weigh-in pictures, the 34T oval is just about do-able with the asymmetric 110mm spider pattern.

      It’s funny how BioPace always gets mentioned when “oval” or “q-ring” is in the header.

  4. Hi everyone,
    Marcin @ absoluteBlack here

    I will try to answer few questions:

    *Reason we don’t recommend riding small chainring and 3 smallest cogs on the cassette is because chain may catch on the shifting ramps from big ring. This is not a rule but may happen on small frames with short chainstay. But in all fairness Shimano is not recommending to use these gears either because chain in such gears has a lot of slack and rear derailleur cage is almost touching the cogs, not to mention that you will wear drivetrain much quicker (SS riders know that bigger chainring/cog combo is better for durability for a reason). So if you ride in such combination often you do something wrong and should consider changing size of the chainrings to avoid those combinations or changing habits. Riding on outer ring is more efficient and this is well documented. So it’s always better to ride for eg 50/16 instead of 34/11. Same ratio but on 50/16T you don’t loose precious watts vs 34/11…

    * Smallest oval ring that can be fit to Shimano 110/4 assymetric cranks is 34T. No way to fit smaller. This is because ovality of the AB ring coincide more or less with bolt holes in the crank. 34T ovality is 6.5%. Great for spinning uphill.

    This is actually another proof oval rings make sense. Shimano positioned those 4 bolts exactly in place where biggest forces are located from pedaling to support the chainring (by bringing bolts closer in power zone). This is how they got rid of weight and unnecessary 5 bolt “old” design. They figured out where the maximum forces are when you pedal and reinforced those places only. Leaving empty space in the “dead zone” of the crank (That is when crank is vertical to the ground). This is why there is no bolt in front of the crank arm – because there are no forces there.
    This is also why our oval chainring has smallest diameter in dead zone and bigger where you can push hardest.

    * Biopace. I knew it will surface again, so we have great videos on our home page explaining why Biopace was a disaster and how we are different. Biopace and Absoluteblack chainrings are completely different in terms of design and work. Idea was similar but execution entirely different. So if you tried Biopace in the past it is not the same thing. We are so sure that we offer 30day guarantee. Have a look at our page to find out more.

  5. There are potential downsides to oval rings that are never pointed out from a biomechanical standpoint. I’ve been riding on an Absolute Black oval ring on my mountain bike for 2years. It is my only bike. There is a lot to like about it, and I drank the kool-aid in a major way. However I developed really bad knee pain in my patella region. Something that has never happened to me in my lifetime of cycling. My knees have always been rock solid. What makes the oval ring seem so great is that it fatigues your quads less, and gives you a perceived resting phase on the downstroke. However it transfers way more load to your knees on the downstroke, especially when standing and pedaling. You can vaguely compensate for this by shifting your hips further back behind the bottom bracket when standing, but this places you in a weak position. I switched back to a round ring, and within a few weeks, along with some rehab protocol my knees where back in A-1 shape.
    I miss the oval sometimes, but joint health trumps any advantage it offered me. I just wish I would have realized this sooner.

    • Hi Max,
      You would be our first customer who actually developed any pain in the knees from oval chainrings on hundreds of thousands sold in last 4 years. We never heard from you any information. So Please get back to us. I would be Very interested in your case. We could pay for medical assessment of your case.

      We have customers that did have an old injury or just problems with knees and when they moved to our oval chainrings pain has greatly reduced or disappeared. Just check our FB comment section, don’t take it from me, see what real users say. This is completely in line with science because Oval chainrings that are designed correctly actually reduce the stress on the knees – not increase.
      Reason behind is that we reduce the spikes of the power you generate. This is where improved traction comes from and smoothness of pedaling. Oval chainrings regulate your power delivery in the way of smoothing out the power curve. So your max power – that is max pressure on the knee is reduced. You can check that yourself with Pioneer power meter which plots you the graph of tangential and radial forces in 360 view. Compare oval and round and conclusion will be obvious.

      So my best bet in your case is that you have used one size too big of a chainring for yourself. But this would happen as well with round rings if you change a ring to too big and try to push like you did before with smaller one.

      We always promote the rule that if you have used for eg round 32T – go oval 32T. If you decide to go 34T oval then such gear is much bigger than your old 32T round was.

  6. I will further elaborate on the knee pain.

    If you do comparison ride with Pioneer power meter (only PM that shows precise measurement over 360deg for oval and round rings) with round and oval rings this will be apparent:
    (0 deg is crank vertical up at 12 oclock)
    Round ring:
    *Large power spike around 90deg (cranks 3 o’clock =horizontal) – It’s of inverted parabola curve.
    *75% of max power starts in the parabola as early as at 50deg (2 oclock) and finishes at about 100 deg.

    Oval ring (same conditions):
    *There is no spike but flattened parabola curve of almost same value from 85 deg to 120deg that is lower than the spike in the round chainring.
    *75% of max power starts at 70deg and finishes at 135deg.

    If you ever did squats you know that ACL ligament in the knee is loaded to a greater extent between 10° and 50° compared to 50° and 100° of knee flexion. This is well documented medical fact. Another words the straighter the leg is when loaded the less pain you get.

    As you see from above comparison. Round rings strain the knee much earlier in pedal rotation than oval ones. Oval chainrings “push” that parabola later in pedal stroke where your leg is (and knee) is more extended – this is where you can actually push and don’t strain ligaments that much.
    This is where the “less knee” pain from oval rings comes from. No magic, but simple mechanics.

    • I think it is easier to read up on Rotors site for more information. Absoluteblack did just copied their work and brand it as their own ideas. Good quality but stealing is stealing. At least they can give credit to them.

      Also Rotor Inpower PM have the best technology to measure oval chainrings.

      • Hi Terry,
        Thanks for the comment. I understand you would like to know more about oval chainrings and their different types.

        Saying we copied Rotor is like Saying Rotor copied Shimano because they produced oval ring earlier than them. And saying Shimano copied it from another company and so on… Oval chainring idea is as old as almost 100years. So which idea did we copy? Same apply to the “bike”.

        If you want to be specific then you would learn that Rotor has it’s own patents for the shape of the chainring and other features.

        We use different shape, ovality and timing to what Rotor uses on their chainrings to start with.

        Rotor claims power gains. We don’t, as “power gains” don’t exist in such shape of the rings and it has been proven already numerous times. Theoretical power gains exist with ridiculous shaped chainrings that are over 30% in ovality that no one would want to ride as it would be extremely difficult.

        So while Rotor optimizes their chainrings for “power gains”, we do opposite and optimize it for smoothness of pedaling stroke as this is where real gains are and are a trigger to other benefits we claim. This is also why many of Rotor users switch to our chainrings and feel a positive difference while pedaling. We have plenty of comments on our Fb from real users, so don’t take my word and have a read.

        With Rotor, adaptation time is up to 6 weeks. With ours is less than one ride and in most cases less than 20min. Because we designed the ring differently to achieve that.

        Rotor is a great company and they make nice products. However we do things differently as we have a different objective than them, so result is different despite both rings are “Oval”. They are as far from each other as coupe and sedan. Both are cars…

        To prove point further lets throw Osymetric to the mix. They are non-round or almost oval if you like. They are optimized for even more “power gains” than Rotor and the riding experience is Very different (and strange) to the round or Rotor or Absoluteblack.

        Every company produces different shape that behaves differently despite they may look similar at the first glance. So Oval from brand A is not the same oval from brand B. It’s worth remembering it.

    • Hi Absolute Black. I used a 30tooth Oval on my 29er. I never changed chainring sizes in the course of 2years. I used a 30 and 32 tooth round ring before I started using your Oval. What you point out as the thing that you believe alleviates pressure on the knees is what I believe caused my particular problem. The later push of the parabola phase, to when the knee is more extended puts extra pressure on the on the knee joint. Almost like coming down too hard from jumping. It is this physical short cut that I believe strained my knee joint. The hand off of power is too quick, creating extra shock on the tendons. I find now that I am using round rings that transition is smoother, and my larger muscles let me know sooner when to back off.

    • Hi, just wanted to add my experience to your chain of messages. I need to tell you that i have had an ACL reconstruction on my right knee in September 2014. I have ridden more than 10000 miles since. Just got my new Absolute Black chainrings mounted last week end at my dealership. Rode for the first time with new pedals and did 40 miles. Came back home with a slight pain on the left side of my knee. Got worse all week in the knee and calf. I first thought i had made a bad movement with my new pedals or even did not set them well.
      Tried again this morning to ride my bike, putting my old pedals just to avoid to changes at the same time. After 10 miles i started seeing the pain coming back and i had to stop and call my wife so i can avoid an injury. I clearly noticed the slight movement left to right when i was pedaling which was certainly giving me this pain. I do not want to accuse AB for this of course. But i think that this technology may not be suited at least for me and maybe for people who have had ACL reconstruction in the past. I am sas because in the mean time, i found the change rigs excellent… great shifting, even better than with my standard rings, great sensation and overall better power… BUT, i will have to get them replaced tomorrow to standard round rings again. Now again, this is my own experience with my own knee. I sill recommend this technology to everyone

  7. Yeah, I also noticed how elegant [email protected] avoided mentioning Rotor and also not mentioning that Inpower cranks are indeed as accurate as the Pioneer. Go figure… But a bit of bad style IMO.
    Disclaimer: I have Inpower and I’m very happy about it.

  8. I have been using rotor rings for years and love them on both mountain and road bikes. I would love to believe the extra power or efficiency, but either way the “traction control” and smoothness was the first thing I noticed riding ovals mtn biking. Everyone I know that uses them including me has had reduced or non-existent knee pain, when they had it before riding round rings.

    That being said, as a Personal Trainer sometimes things just don’t “work” for certain peoples bodies, bones, joint angles, tendons etc, even when they should. You look at trends and tendencies but sometimes you have to change the movement/exercise/game plan.

    I just switched out my old rotor road rings for Absolute Blacks premiums and love them. They shift better for sure. I would love to switch over on the mountain bike as well, but prefer a double so I can get the most “ovality” out of the bigger ring for as much of the race course as I can handle.

    Absolute Black, Any chance you will be producing a mtn double? I realize with Sram Eagle I can achieve the same thing with a single 36(and get the much needed low range) but that is way out of budget for a while.

  9. Also, the fact that Absolute Black is willing to pay for a medical eval for Max is pretty amazing. Now that is customer support!

  10. I have been riding my bike for a total of 300 plus miles including climbing hills since I’ve changed to absoluteblack premium. I’m so pleased with this product that i also changed my other 2 bikes, including my TT bike. I’m hoping that they will make 55T or 56T for my TT in the future..

  11. Hi Everyone, I’ve just switched to an AB 34T chainring but only the 34 and nothing else. After 10 days, I must confirm that the difference is phenomenal. So who am I, not a pro but a 50+ year old who lives in the French Alps and has climbed every major Cat 1 or HC Col in the region with a standard Ultegra compact set up. The change to the AB chainring gives you more torque, a longer power stroke and does not induce fatigue as quickly. For comparison on some of my test routes i.e. monthly fitness assessment, I can maintain pretty much the same cadence but on the next smallest cog. I’m a convert but that’s just me. Each to their own but I’m about to buy a set for my wife!!!

  12. I really would like to use a set of AB ovals on my Ultegra compact group set. I am convinced they will be better than round, but, being a tart, I don’t like the fact that their road rings don’t blend into the crank arm like the originals. There is an ugly step.
    Both my XC and Enduro bikes have AB oval rings – they pedal so smooth and climbing is like having a small electric motor to help the pedal stroke over the dead zone. It’s sort of like fixed wheel sensation.

What do you think?