Long Term Review – Absolute Black Oval Chainring

Photos Jon Harris

Remember Biopace chain rings? They are back… kind of. Single chainring drive trains have resurrected a concept from the 90’s- that didn’t work with multiple chainrings. In concept oval rings should smooth out the torque transfer from the cranks to the back wheel. No matter how much work you have put into your pedal stroke, you do not produce power evenly through a pedal stroke. The idea is that an oval ring can make the most of the stroke where power is produced by giving you a slightly higher gear, and minimize resistance where it isn’t by lowering your gear.


Here’s what Absolute Black has to say about Biopace

Word on BIOPACE – Please understand that this is not Biopace technology. Shimano created Biopace with the completely wrong orientation of the biggest radius of the oval. Instead of positioning it in power zone which is slightly below the level of the crank, they clocked it to the dead zone where human generates least power. The result was that in power zone pedaling was too easy and in dead zone very difficult. Exactly opposite to how it should be.


Absolute Black said that I would feel a smoother pedal stroke and the oval would be easier on legs while climbing. In fact they go so far to offer,”with oval rings rear tire traction improves greatly on loose and slippery terrain. Your legs will be less tired and your speed improved. Climbing will become easier than ever before. It is world’s best oval chainring.” That’s a big promise. Could a simple chain ring really make me a fast as Nino Schurter?

Absolute_Black_1

Something looks wrong here… Oh my mistake it is just an oval chain ring. Looks odd doesn’t it?

Well no it can’t, but after years on round chain rings were there any big noticeable difference that I could feel?

I have spent some time on skinny tires and countless hours on a trainer over the winters smoothing out my pedal stroke. In fact I own a trainer that measures my torque output while analyzing my pedal stroke. I know that my pedal stroke is pretty good. Sure it’s oval shaped, but it is smooth.

Traction isn’t something I particularly struggle with either. Part of the learning process of riding a mountain bike is to understand when you can lay down the power and when traction won’t allow it. Shifting weight and being judicious about when to apply juice; these are essential skills to any rider who wants to climb challenging terrain.

Absolute_Black_2

Here is a fresh non-oval direct mount ring from Absolute Black. To be honest I was going to fit this once I felt I’d ridden the weird oval ring enough. As you can see I haven’t swapped it yet. Absolute Blacks rings are nicely machined and finished.

Skepticism in place, I fitted the chain ring. I took it for a quick spin around the block and I immediately noticed something was weird. The pedal stroke just felt strange. There is a sense that your drive train is full of treacle at certain points of the pedal stroke and then it changes to being perfectly lubed. Well a spin around the block does not constitute a test, so here I am 6 months on.

Absolute_Black_3

The Absolute Black chain rings come with a narrow-wide tooth profile and I haven’t had an issue with a dropped chain once.

Oval rings do make your pedal stroke smoother. After getting used to the feeling of the oval ring I stopped noticing it. I actually threw my mountain bike on to my trainer and compared the profile of my pedal stroke with the oval ring to a regular circular ring (yes, I did that for you). The profile is much more ’round.’ I can’t say that I noticed that as much on the trail, and it seems there are too many variables in play to make that measurement. The science dictates that maybe there is a benefit there and who am I to argue with science?

Absolute_Black_4

Dirty, dusty and well ridden. After an initial weird sensation I now don’t notice the ovality (ovalness?) of the Absolute Black ring. Can I attest to it saving my knees? No, but I can say that it does smooth out the torque inputs to the drive train and that can’t be a bad thing.

There’s so much I can’t confirm about Absolute Black’s claims. I can’t hold up my hand and swear that my knees feel any better after a ride. I can’t say the traction was improved enough that I was able to clean a climb that I hadn’t before. But I didn’t feel that there were any negatives either. Since I’m an engineer I’m going to have to trust physics on this. The ring stays.

Absolute Black has an oval for an impressively wide variety of cranks. (They make round rings as well for those who aren't down with ovals)

Absolute Black has an oval for an impressively wide variety of cranks. (They make round rings as well for those who aren’t down with ovals)

The Absolute Black Oval Ring  comes in 26 to 34 tooth equivalents. The actual ring profile varies obviously. My 32-tooth ring, for example, goes from a 30 tooth to 34 tooth profile around the circumference. It is available in direct mount models for Race Face Cinch and SRAM cranks as well as bolt on models. Pricing varies but right now they retail for $66USD £45.99 and €56.99 for the SRAM direct mount model.

Absolute Black have recently announced an Ambassador Program for anyone that might be interested in checking out their rings and other components. Check out the details here.


Ready to step back in time and try an oval ring again (albeit a different oval)?

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Comments

rdm
0

I wish someone could explain how Shimano, with all their engineers, could have designed their Biopace rings with the wrong timing.

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dj
0

I tried this exact brand on my 29er. 30tooth. I liked the feel and gave it a good shot for 3 months of steady riding 3/4 days a week. My knees became quite sore and I couldn't tell why. Switched to a round 28t and knees got better. Not sure wot it means but that was my experience…

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wig
0

Chris Froome's road bike is easy to see where the power is. I would need to pedal up skinnies to judge a smaller ring. It might help. Thanks.

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awesterner
0

I think it was a good, honest review. I tried Osymetric rings back in the day (2003?). We were young, these things were free, we tested them back to back repeatedly (using SRM), we went back to standard. The economy and the promised 5w just wasn't there for some of us. The idea hasn't changed, so I'm not surprised astute reviewers would come to a similar conclusion.

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wncmotard
0

I've had one of these for about a year, used it only my single speed. Ran it for about 6 months, then back to round for about 4 months, and now back to the oval. I can definitely tell a difference on standing (which is almost always) climbs where traction is a factor, like loose over hardpack. I get a noticeable, not huge, but noitceable improvement in traction and reduction in wheel spin. I notice I can also stay seated just a bit longer before feeling like I'm not on top of the gear anymore and have to stand or just mash. I'll be leaving it on the SS from here on personally.

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andrewbikeguide
0

I have been running one of these chainrings (32T/ 104BCD) for about three weeks now and even with my limited leg power (post ACL surgery) I can feel a slight improvement on climbs. Feels odd to begin with ie one can feel the oval but then smooths things out when in real use. I will continue this experiment and see where it leads.

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john-utah
0

Ive been riding ovals for 3 years already using an asian brand called Doval they have a large product line and have been making longer than AB or anyone else except q rotor. I can attest that my knees which have been injured very much like oval rings. I have found myself completing climbs always earlier than expected with less perceived effort. Also I have found myself climbing more often in my big ring instead of my granny. I run 2×9 21×36 both are oval. I wore out my first set had to switch to round while i waited for the mail to bring my new set and hated it. I am happily back ovals and loving it.
My 36 also is adjustable to where the power point is like q rotors.

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reformed-roadie
0

"But I didn’t feel that there were any negatives either. Since I’m an
engineer I’m going to have to trust physics on this. The ring stays."
That's it? That is pretty weak as far as a review. Sorry.

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jonathan-harris
0

I thought it was a pretty honest comment. Maybe you missed the comment that I put my mountain bike on my computrainer (not a simple task with a rear through axle) and ran the pedal stroke analysis to confirm that my stroke was smoother. It is.

When you are riding off road though there are so many variables that it is hard to quantify if the ring is giving you better traction up a climb due to that smooth pedal stroke or you are doing a better job of distributing your weight that day. When I rode like a hack, purposely trying to spin the wheel up a gravelly climb it was harder to get the rear wheel to spin up… but I don't ride like that and I doubt many readers do either. I think for the flat pedal riders out there it will be even more beneficial on a technical climb where traction is at a premium.

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GladePlayboy
0

After having just switched to flat pedals on my trail bike I concur that the oval ring helped me out on techy climbs…

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badbietz
0

I would like to see some back to back climbing number with cadence, heart rate, average speed and time with a 32T Round and 32T Oval. I think that would help answer the question most people want to know, is it faster with the same effort, same speed with less effort, slower or the same.

I think you would have to do the same climb a few times with each set up and then average the numbers and compare the averages in each category. I've seen a few reviews on the oval rings but no one has provide this type of data.

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nat-brown
0

I think that misrepresents the review. My take was that any benefit was small enough to make it hard to draw a conclusion. That says something.

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cooper
0

As someone with a OneUp traction ring on right now, this is about the sum of it.

Although I've heard the difference is much more discernible if you're on a hardtail, rather than a 155mm bike…

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cam@nsmb.com
0

Perhaps you are used to being fed bullshit. We believe in telling the truth - rather than building hype - and this was Jon's actual experience with the product. Not to mention that two riders below, who have also used the product, agree with Jon's conclusion.

Beyond that, saying 'that's it' is kind of ridiculous when that wasn't it. He put it on his power meter FFS.

Reply

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