Absolute Black Oval Chainring for Race Face Cinch Cranksets - Review
Pairing Absolute Black's direct-mount oval chainring with the Race Face Turbine Cinch crankset gives the rider the option to determine where the sprocket will be most effective in the crank's rotation. The 32-tooth oval is roughly a 30t at the small diameter and a 34t at its widest point.
Serendipity, perhaps, but when Race Face developed the 16-tooth splined interface for its Turbine Cinch crankset, it answered the prayers of Marcin Golek. Golek is the founder of Absolute Black, and a staunch believer in elliptical-shaped chainrings as a superior method to deliver power to the ground. Marcin discovered through testing his un-round chainrings that differences in leg length, and the rider's position over the crankset require slightly different "timing" in order to ensure that the major axis of the chainring was in position when the rider was producing peak torque.
The concept is not new. Rotor, the world's most famous oval chainring maker, offers a number of timing options for exactly those reasons. Turns out that the 16-tooth spline interface of the Race Face Cinch crankset offers three useful timing positions for the Absolute Black chainring: "Neutral" (Marcin's preselected position that he believes will work for just about everyone), and either 22.5 degrees ahead or behind that point. The drive-side quick release feature of the Race Face crankset means that the chainring can be re-timed in less than15 minutes, without removing the bottom bracket axle from the frame or breaking the chain.
Absolute Black is headquartered in the UK, where their design, marketing and testing takes place. The chainrings are CNC-machined from 7075-alloy aluminum in Poland and then finished in the UK. Chain retention of their narrow-wide tooth profile is warrantied for 12 months and you can get them with 30, 32, or 34 teeth, in green or black anodized colorways. Our 32-tooth oval ring weighed 60 grams and carries an MSRP of $66 USD. Absolute Black also makes a full range of oval chainrings for SRAM direct mount and the most popular four-bolt cranksets.
Absolute Black
Oval Sprocket Theory
For those who are not up to speed on oval chainrings, the concept is not a re-introduction of Shimano's 1980s-circa BioPace. The major axis of the oval chainring is timed to arrive as the leg develops peak power, while the smaller, minor axis is timed to arrive near the "dead-stroke" to increase the mechanical advantage of the crankset when the legs provide very little power. Theoretically, the result is more constant torque is generated around the crank circle. For mountain bikers, that means more climbing traction and the ability to maintain momentum in situations that require high power output. Worth noting is that oval and a round chainrings with equal numbers of teeth will propel the bike forward at the same speed at a given rpm, so only power delivery and leverage rates around the crank's circle are affected. On the same subject, switching to an oval chainring causes little or no change in chain length as it rotates, so the rear derailleur cage doesn't rock wildly back and forth with every pedal stroke.
Ride Report
Installing Absolute Black's chainring to the Cinch crankset was surprisingly easy. The Race Face drive-side crank pops off the end of its 30mm shaft with an eight millimeter Allen wrench. A threaded retention ring fixes the spider (or direct-mount chainring) to the crankarm, which fits a readily available splined bottom bracket cup remover (Park Tool BBT-20). To index the oval Absolute Black chainring, you line up a dot machined near the spline with the crankarm. The entire process takes about as long as it does to read this article - which encouraged me to try all three timing positions with the oval ring and also compare it with the stock, 32-tooth Race Face ring on the same trails.
We used the Commencal Meta V4 to test the chainring. Its 72-degree seat tube angle is slacker than most trailbikes, which should have favored retarding the sprocket one click counter-clockwise, and initially that seemed best, with a very gradual transition from the larger to the smaller axis of the sprocket. Advancing it one click clockwise had the opposite and negative effect - causing the leg to speed up dramatically as the knee reached full extension. Climbing a steep grade with a smooth surface revealed that retarding the sprocket one click felt better because that was the position that caused the sprocket to perform and feel much like a round chainring - a strong acceleration, followed by a brief lag. If there was any doubt, both the round and the oval ring left the familiar broken line scratch marks on the dirt. When I returned the sprocket to the middle position, the broken lines created by each power stroke on the pedals were smoother and closer together - an indication that I was making torque where my legs had previously been coasting around the crank circle.
The Race Face lock ring is installed using a standard splined bottom bracket tool, like the Park BBT-22. The crank is self-extracting, which makes an easy task of switching chainrings or timing.
I decided on the middle position even though there was a distinct pulsing, created by the legs speeding up as the oval sprocket turned through its smaller axis - a sensation that made it awkward to spin the cranks at my 90 rpm cruising pace. Two, maybe three rides later, the pulsing sensation was gone and I could spin the cranks as well as with the round ring. I normally ride a 30 tooth chainring on a 27.5-inch-wheel bike, so the 32-tooth ring put some heat into my legs on the steeps, but that helped to clarify where I was making up ground and where I may have been slower with the oval rings.
There was no doubt that I was consistently faster when climbing technical terrain, because I could keep the cranks turning in familiar situations where I had flailed on the pedals using the round ring. I lost some momentum on trails where the grade changed constantly, because I found that I was shifting gears more often with the oval sprocket. That said, I could hang in a taller gear for a longer duration than I could with the round ring if I was willing to slow my cadence slightly and gut it out.
Pinkbike's Take:
 | To end on a practical note, Absolute Black's take on oval chainrings provides its most palpable benefits during those moments when you are pushing the pedals in earnest, especially against a lot of resistance, like plowing through sand or mud, working up a steep grade with variable surfaces, or getting up stepped rocks and roots. Pitted against a round ring, it pedals about the same over smooth, flat terrain and when topping rolling climbs out of the saddle. Speaking to the timing aspect of the Race Face/Absolute Black marriage, I ultimately didn't need it with the Commencal's 72-degree seat angle, but in retrospect, I had the option to experiment and make an educated decision. Plus, retarding the timing allowed me to get used to the sensation of the oval sprocket by moderating its effects, and then move up later to the optimal timing. Initially, I was worried that the oval ring would work my knees more than I wanted. After switching back to the round ring for the remainder of the Commencal review, however, I was reminded of the constant pulsing (which we have all learned to live with) and ultimately, the oval sprocket proved easier on the knees. If you own Race Face Cinch cranks, and you have 66 bucks to burn, Absolute Black's oval chainring would be well worth a try. - RC |
MENTIONS: @COMMENCALbicycles, @absoluteBlack, @raceface,
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Performance wise, they are great! Ease of a 30, speed of a 34 ring I'm not so sure, but I would buy another one, and that I think says the most
I have been to therapy, and that has certainly helped also, however the pain did come back whilst on the bike. With this new ring it simply hasn't
also
As I said, "I have been to therapy, and that has certainly helped also, however the pain did come back whilst on the bike. With this new ring it simply hasn't"
.............
inner plates are same on 9 and 10spd chain. But outer plates are different. 9spd chain has wider outer plates so chainring/chain will fit loose on thick teeth.
So in order to keep good retention 10 or 11spd chain is needed. If we were to make 9spd narrow wide compatible chainring then 10/11 spd chain would not fit.
To be more interesting 10 and 11 spd chains are identical internally! in both narrow and wide links, but the outer dimension of outer plates on the 11spd chain is thinner. So chainring sees the 10 and 11 spd chain as exactly the same one, but outer diameter of 11 spd chain is thinner = more clearence between cogs on the cassette = less rub in the mud
Concluding you can use 10 or 11spd chain with your 9spd cassette and they will perform great.
Companies being honest about backwards compatibility and not trying to force you to upgrade cos your drivetrain is over 15 minutes old?
Mind. Blown.
Well isn't this lovely! Hugs all round
gradworks.umi.com/36/74/3674000.html
Though I would assume being clipped in lets cyclists put more force into the pedals at slow cadences because they don't need to worry about slipping off the pedals.
1. How many experiments did you design to prove your master thesis ?
2. How many experiments did you design to disprove your master thesis?
Wouldn't your knees and hips moving slower be better for them? Thus oval chainrings would be better for your joints?
Analyzing pressure on the joints using each type of chainring might be the next step in this study.
@ov3r1d3 engine power and human power production aren't completely analogous. You aren't tuning a power band to work at specific parameters in a person. Additionally, optimal cadence for power production wasn't different between round and non-round rings, so this isn't an issue.
@BrightBulbPhoto These studies were actually conducted by a colleague in fulfillment of his Ph.D. I helped in data collection and ergometer design/maintenance. They studies also weren't designed to prove or disprove either chainring orientation as better, but rather collect data and analyze post hoc for differences. We just as happily would have reported that non-round rings were better if it were true. Hope that makes sense.
@Rasterman not necessarily. Muscular power production is dependent on two main factors, force production, and shortening velocity. In an isolated environment, faster shortening velocity would require less force production, while slower shortening velocity would require higher force production. There is always a trade-off.
Aside from this, my limited knowledge in biomechanics prevents me from making any additional arguments
So oval rings give you an effectively smaller chainring when your legs have very little mechanical advantage, and an effectively larger chaining when your legs are at their strongest. What's not to like about that?
I won't dispute your findings because this stuff is too simple to argue about. You were probably perfectly correct in your measurements and conclusions. You just weren't measuring (or thus drawing conclusions about) the things that make these chainrings better than circular rings.
Just do some A/B testing (that was a pun) and you'll feel the difference. It's not night-and-day, but it's also impossible to overlook.
I am telling you tho. It essentially puts a power-band on your cycle.
I have been running it this season, and so far it is quite nice to have. Tho it took a little use to having to down shift into a harder gear to stand climb the hills. A somewhat counter intuitive procedure. It has also been a little tricky to set-up. Regardless. This is a great product, that I am well over the initial cost. Coming from a life-time of 3x8 or 3x7 speed drive-train systems. Absolute Black's oval chain ring made my intro to 1X drivtrains, a good one.
Highly Recommend these products.
And have run into ZERO problems. Just make sure your 'standard' style chain-guide, can accommodate sizes larger than the Oval chain-ring than you intend to use. I found it helps with clearance.
Example. I run a 34T oval in a chain-guide sized for 36T and up.
This also gives the option to switch out the 34T oval for any larger sized standard ring. Not sure if/when that will happen. As I just found out that AbsoluteBlack now stocks 36T ovals...
Marcin at absoluteBlack here.
Many thanks for the comments, especially from people who already used it and know how it feels like.
to sum few things up:
* This is not Bio-pace. Most of you already know that, but seem there is still a lot of people who do not read article except bottom line
* Our rings DO NOT generate more peak power. See our website - we never claimed you will generate more power with them.
absoluteblack.cc/raceface-oval.html
What we DO claim is:
1 Your traction will improve Greatly due to smoothing out of your pedal stroke (power to pedal).
2 Your mashing style of pedaling will suddenly smooth out and you will feel you pedal very constantly and easy
3 You will see great improvement riding clipless or flats. With flats people usually see even more benefits as this group tends to mash morethan people riding clipless
4 You will ride quicker - this is bit complicated to explain. You will not ride quicker because of "more power" but because of smart distribution of power you already generate. Oval ring smooth out your delivery of power to the rear wheel in that way where you get less of slippage and more constant/ steady pedaling. So because your pedaling is now more constant you do not waste energy and not go out of pace due to rear wheel slip. All this will get you to the top of the hill quicker. On top of that ovals utilize your muscles in different way so you also get less tired. This also contributes to greater speed because you can keep same speed for longer. This ultimately means that you will cover distance from A to B in shorter time than with round ring. Simple.
5 These rings WORK on singlespeed with no problem!. Chain growth is extremely small. You do not have to have chain tensioner or anything like that. Way you set it up is to tension properly the chain when biggest part of the ring is at 12 o'clock. The at every other point tension will be just a bit smaller. This also means you will not put any strain to your bearings or cogs. Simple. on SS oval works miracles.
6 Your clutch will be absolutely fine. In extreme cases(long cage) cage moves only about 1mm at the lower pulley. This is less than distance causing clutch to work! So really you do not have to worry about that.
7 It does not require long time to get used to. On average 1-10 minutes.! So people say it takes them one ride. Some people say they do not feel any strange feeling at all from the start.
We sold by now Huge amount of oval rings and we do not have a Single customer (!) who would be not happy with it or did not see a positive difference. People love it.
We are so Confident in this product that I will personally swap your oval ring to our round one if you will be not happy trying it for 3-4weeks. You can call us crazy but they simply work like it says on the tin. This is best single bike component you can get to your bike and greatly improve your ride from the start.
....I think.
I have been running it since April with no issues, as expected. Not a new thing to me, as I previously wore out 3 Rotor Q-rings over 3-4 seasons. As they became harder and harder to come by, and increasingly more expensive - I was happy to find Absolute Black last year. I ordered one in the fall and had it ready to install on my XT crankset this spring.
I feel no difference between it and the 34t Q-ring. The shape and timing are identical to Q-ring mounted in the middle bolt position.
And no, you don't need to run a tensioner or anything else with it on a single speed. Either of the rings (Q-ring or AB) will work and retain the chain just fine. Just make sure that you set up tension with the ring's "peaks" at 12 and 6 o'clock - that's where the chain is the tightest. Everywhere else there's a little growth, but it's not significant enough to cause any issues, especially under tension.
As I said, with the bike in the work stand and spinning the crank (either way), chain is the tightest with the ring's "peaks" at 12 and 6 o'clock position. It definitely and noticeably slackens anf tightens throughout the full rotation.
I'm not talking about feeling or tension felt under power, strictly about the fact that chain tension is not constant.
Look how many people are still comparing to Biopace? Have you guys ever read a single article, including this one, about new ovals They ALL mention how they are completely different. SMH.
Studies may show power production may be the same, but seems these tests are limited. Assuming perfect pedaling, sure, but a) standing mashing pedals is different than sitting and evenly pedaling, b) smoother power can provide more traction than bursts of power, despite same total power. Nor do the tests seem to acknowledge joint pain, that lots of people report as being a significant improvement with ovals. Lab tests and reality aren't always the same.
I ask that because I nearly trashed my Turbine crackset the last time I tried to auto-extract it. The (alu) bolt was completely stripped, requiring to replace it.
Now I prefer to use my old ISIS crank extractor instead (much more stronger non-moving threading in the crank).
Are the benefits of oval chainrings more pronounced at lower or higher RPM? I see the pro peloton guys doing time trials with big 53T rings, doing 90 RPM.
Those cranks are sweet but the machined area near the crank bolt bugs me as it looks impossible to clean. The coarser machining steps will get grungy the first ride, and stay that way. Its not a part of a crank where I want things hidden by dirt.
Agreed, I just took a look at a blue RF n/w 32t ring I used for 6 months and the anodizing is scuffed on the chain contact parts. Would be interesting to know how long RC ran this green ring to get it looking like that. Its not really an issue, but its awesome when coatings are indestructibly strong.
Our rings hold more than 12 months with normal regular use. This is more than any mainstream brand on the market currently. And if you are a casual rider and chainge your chains regularly it will hold few seasons...
This "wear" is almost not visible when chain is on the ring.
www.sheldonbrown.com/biopace.html
www.rideabikes.com/index.html
www.b-labs.org/oval-chainring
ovalised chainrings are not new, they have been used in road cycling for many years including those originally made for EGG, by Highpath a small UK engineering company. Eggrings were used by Chris Boardman when he smashed the world record on the Lotus superbike, as well as many other Olympic record holders.
www.cornant.uk/eng/eggs.html
When done correctly like Rotor or O-Symetric, it can work very effectively.
ep1.pinkbike.org/p6pb12026507/p5pb12026507.jpg
gradworks.umi.com/36/74/3674000.html
Both were used in this study, and I witnessed much of it take place, so I know it was sound science.
Just search for "biopace."
Seriously, that's what they are.
(I have Absolute Black's rings on two of my bikes, by the way.)
Sedentary way of life, stress, poor posture, extra weight or round chainrings can contribute to knee pain.
OVALDISK® brand offers complete SAFE, EFFECTIVE & SIMPLE solutions for knee pain sufferers regardless of age, gender or profession with unique patent protected invention.
Another way to look at it: the total circumference is 32 teeth, and the chain is always engaged on half of the total circumference, or 16 teeth. Sometimes that's 16 teeth on an oval that's stretched vertically, sometimes that's 16 teeth on an oval that's stretched horizontally, but it's always 16 teeth.
Realistically of course the chain doesn't always wrap around PRECISELY half of the chainring on most bikes, so there is a TINY variation in total wrap, but it really is tiny. I run one of these on a single-speed with tensioner and the tensioner doesn't move enough to notice.
However I have one of these on a Canfield Jedi where the wrap is smaller than usual due to the upper pulley (it would be a lot less than half, but the chainguide compensates somewhat by adding wrap on the bottom). The derailleur does move enough to notice, but the movement is very small.
www.youtube.com/watch?v=k79wZSAbeC0
www.youtube.com/watch?v=9QC7OSTtyp8
That hideous wheel is actually kinda cool though. It looks square because of how the "ruffles" are arranged, but it's circular when viewed from the side. Math. Must be terrifying in corners though.
I want to ride that eccentric laced scooter...on a pump track.
Kidding aside, what is the difference between the Bio-pace rings from the 80s and these oval rings?
Non-round chain-rings are still a marketing strategy, not a performance booster.
gradworks.umi.com/36/74/3674000.html
"what do you mean warped!?"
"They are ovals man! We can't sell these!?"
"Wait, I got it! Oval chainrings are actually better than circular ones!"
"What are you talking about no they aren't!"
"Shhhhh! Nobody will know that! We will just make up some garbage about power exchange or something"
"...brilliant"