Absolute Black Oval Chainring - Review
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Absolute Black is a quality aftermarket parts maker from the UK that was one of the first mountain bike suppliers to jump on the oval chainring movement. Absolute makes oval rings to fit 104-milliemeter bolt circles, as well as direct-mount rings for SRAM and Truvativ GXP cranksets. We reviewed the 32-tooth model, which is the smallest option for 104 BCD crank spiders. Absolute Black says the major axis is the same as a 34-tooth round sprocket, while the minor axis is close to that of a 30-tooth. Proper spacing and threads are machined into the anodized aluminum sprockets, and the 50-millimeter chain line is corrected for one-by drivetrains. Chain control is assured by a narrow-wide tooth profile, which is a good thing, because oval rings are tricky to protect with a conventional guide. Absolute Black sells oval rings in either 32 or 34-tooth sizes for 104 BCD cranks and offers a 32-tooth direct-mount for SRAM GXP - all for $66 USD. Colors are anodized green or black. Stated weights for the 32-tooth models are 41 grams and 59 grams respectively. Absolute Black
Absolute Black's 30-tooth round direct-mount chainring for SRAM GXP cranks next to its 32-tooth oval chainring for 104 BCD cranks. Reportedly, pushing two extra teeth on the oval ring requires a similar effort as the smaller, round sprocket.
Pinkbike's Take:
 | Setting up the Absolute Black oval chainring requires little more than lining up the pip on the sprocket with the crank arm to assure that the timing is correct. Because the same number of teeth are engaged at any point of the crank revolution, the ovalized sprocket will not affect chain length, or cause the rear derailleur's take-up arm to oscillate as the bike is pedaled. As a result, switching to an oval chainring with the same number of teeth will not require a chain adjustment. Absolute Black's oval ring is well constructed and beautifully finished, and it mounted up easily to a Shimano XTR crankset. The chain, although not new, was relatively fresh and ran silently on the sprocket from day one. Initial rides with the oval chainring did not produce the "aha" moment I was expecting. A lifetime of spinning round chainrings caused my legs some confusion as my feet felt as if they were speeding and slowing with every revolution. That sensation faded quickly, but there were a two more lessons to learn before I became completely adjusted to pedaling an asymmetrical sprocket. Saddle position fore and aft affects the timing of the sprocket and the legs. I discovered that sliding my saddle one centimeter forward made for smoother pedaling. I also learned that the oval ring favors a slightly lower RPM as well as a steadier cadence, so I found myself shifting more often to stay in the sweet spot. Once sorted, the oval chairing's advantages were readily apparent. Pedaling torque was more consistent, which made it easier to maintain pace up while climbing. Controlling rear-wheel traction was made easier, presumably, because I was getting through the "dead zone" with greater ease, and that allowed me to top some technical steeps that I often struggled with. The slight pulsing sensation could be a distraction on the flats, where minimal pressure was required on the pedals. The pulsing disappears if the rider chooses a taller gear and a slower cadence, or when the terrain asks for more leg power. The bottom line for Absolute Black's oval chairing is that switching to one is a sure way to ease up punchy technical climbs, and it could also be used to widen the gearing ranges of one-by drivetrains by allowing the rider to push two more teeth up front without sacrificing the bike's climbing ability. - RC |
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i suck at explaining stuff. i hope it makes sense to somebody. hahah
am i misunderstanding this concept?
I can see the potential attraction on larger (ie road) rings and with a smaller 1 tooth difference between the two ring 'diameters', but that begs the question "why bother at all?". My memory of Biopace was that it was an interesting idea that f*cked with my young knees...
I would certainly try it first before dismissing it. Especially when one is getting older and one's knee has had an acl tear.
Besides, I thought it was more about how the power is generated and it's delivery rather than the amount generated that was key?
I would assume that the amount of power generated roughly remain the same?
That is why a 30 tooth oval is said to be like running 30/32 ring at the same time..
Biopace had it backwards..=Failure
Human has dead spots in his pedal stroke oooor we are turning circles? Look some people will love it, good on them, just please don't convert everybody saying that ovals are a step forward for everybody. If they are a step forward for RC or someone else I will not doubt it, I only doubt that pseudo scientific mumbo jumbo.
A - on a technical climb one might want to stand up as much as he can to move senter of mass forward to imrpove overall balance and increase steering precision of the bars and balance. Additionaly standing pedalling allows you to use a bit of trial moves because you can dramatically shift your weight back and forward, which is extra important in slippery conditions.
B - you get less chance of pedal strike as it is easier to time pedal strokes (thus you can use longer cranks = more leverage)
C - lower gear allows you to have pretty much all the power on tap so if you need to get over a log or a rock step you can easily do it. If you spin too fast you will never be able to get that front wheel up for desired amount of time.
D - you get more traction as same amount of maximum power is applied on longer deistance. I must say that practising gate starts a bit immensely improved my technical climbing. Where I live, if you ride a trail, most climbs are steep, rocky and rooty as hell.
Gills - ther is NO scientific evidence what so ever that would prove that stomping on the pedals is less efficient than more even pedal stroke and that is 100% disconnected from what kind of pedals you are running. In fact there are two half-scientific proofs made lately that show that A-flat pedal is on par with clipless when it comes to environment with little variables (road and fireroad riding in particular) and the second one showing that standing pedalling takes minimaly more energy than seated pedalling. James Wilson vs rest of the world 2:0. Clips allow you to stay on pedals while you pedal in rough and allow you to stay over the front of the bike more in attack position in rough. They are invaluable for aggro hardtail riders.
www.youtube.com/watch?v=CNedIJBZpgM&list=PLUdAMlZtaV11LAqXNLDr38oTXh9RuyiRY
www.youtube.com/watch?v=PVxGFOb1KTY&list=PLUdAMlZtaV11LAqXNLDr38oTXh9RuyiRY&index=2
www.youtube.com/watch?v=-jh-5TYAtJI&index=1&list=PLUdAMlZtaV11LAqXNLDr38oTXh9RuyiRY
Most recent take on all of things in MTB looks more or less like that: I believe everyone has their own preference but I think I know best and three arguments later everyone goes into everyone should do like I do! My take is: everyone take it easy! You take it easy damn it!!! Calm down now!!!
Others have suggested an oval ring encourages them to pedal at a lower cadence. If true then you would be arguing the case FOR oval rings.
In any case I'm interested to see what Nino and Julien do over the next two years. If this product benefits anyone it should be them.
Do you think the oval chainring favors flat pedals or clipless? And did you experience any knee discomfort due to the "quick" transition through the deadspot?
The transition through the dead spot is not quicker - prehaps a bit slower than with round rings, but the lower effective gear at that point evens out the rider's torque output under power. Round rings feel smooth when lightly loaded, but force the rider to pulse when climbing or putting maximum watts into the pedals, Oval rings pulse slightly when lightly loaded, but create a smooth, even power output during high-watt efforts.
I have not ridden one with flat pedals, but I'd guess that oval rings would help, considering that using flat pedals tend to reduce the duration of the power stroke through one revolution of the cranks.
The primary aim of our study was to examine supra-maximal cycling performance and related mechanical variables in trained cyclists using a new prototype chainring (PC) designed to produce a higher mean net torque (T N mean) than a standard chainring (SC). The main feature of the PC is that crank-arm alignment and lever-arm length change as a function of the crank angle during the pedaling cycle. The PC presents two features theorized to effect cycling performance: (1) out of line of pedal cranks resulting in an decrease in the dead points, and (2) a change in crank arm length inducing a torque different from that of SC during the down- and up-stroke of the pedaling cycle. To investigate this theory, we examined eight male cyclists who performed a 1-km “all-out” cycling test in the following order: SC, PC, and SC. Performance was measured as the time (s) to complete the 1-km test. Mechanical variables included torque (N m−1), crank velocity (rad s−1), and power output (W). We performed our statistical analysis using a two-way ANOVA for repeated measurements and Newman–Keuls post hoc assessment. Our results showed that performance was similar for SC (69.41 ± 6.69 s) and PC (73.33 ± 4.58 s). Torque, crank velocity, and power output were also similar throughout (P > 0.05). We conclude that despite the theoretically benefits proposed by the inventors the new PC investigated in our study failed to improve cycling performance or mechanical variables during a supramaximal test when compared with SC.
I have an Absolute Black NW ring in 64BCD (and their bash guard in 104BCD) that I used to convert my 2x entry level SRAM crank into a ghetto 1x setup. It's held up very well and hasn't dropped a chain once (with an x9 clutch rear derailleur).
Oval/asymmetric style chain rings tend to make people push harder gears, which won't necessarily translate to a natural selection of higher cadence. You'd have to discipline yourself into pushing a higher cadence.
@RC: Did you time yourself on any familiar climbs for comparison? It's ALL about Strava after all. [winky winky]
Wheel size debates.....now this! God help us!!!
Rotor has been making them for years. Many threads of useful user information on MTBR and other forums. Note the multiple holes for changing position of the axis relative to your crank arms. Allows you to adjust to your comfort and capabilities. For 2x drivetrains, but some users reporting 1x setups. Importance of this product is the introduction of narrow wide tooth profiles for 1x, however misses the mark with no adjustability.
In 1989 when I bought my first mountain bike, which was a Peugeot Barracuda, it came with an oval crank set. This technology certainly helped the pedaling action for efficiency and out right sprinting performance, of course then I was younger and I played football (round ball) that certainly helped with my fitness but I do recall, especially in races, that I could climb and power along the straights with ease. I am glad they are returning.
I have used this exact product (104 bcd 32t) on my 29" FS 1x10 since October and tried it on my old SS. I have several hundred miles on the ring and no issues.
Chain retention should have been mentioned. Even with two different times of forgetting to turn the clutch back on, I have not dropped a chain. This thing holds the chain perfectly for me.
There's some RD movement with the 32t and a long cage...I know a long cage on a 1x10 is taboo. The movement is minor. Minor enough that I ran it SS without any chain tension issues.
I won't try and make claims that this will make you faster. I really like how it 'feels' when pedaling and the increase in rear wheel traction while climbing. I used a 34t Rotor Q ring (similar clocking) for a while with a MRP guide and now I get to drop to a 32t, lose the chain guide and drop some weight.
In pro peleton it is widely known that some use round rings for training and ovals for racing.
Many even have oval granny ring only and round big ring so the Sponsors can't see it but they benefit on uphills
"I discovered that sliding my saddle one centimeter forward made for smoother pedaling. I also learned that the oval ring favors a slightly lower RPM as well as a steadier cadence, so I found myself shifting more often to stay in the sweet spot."
Works with plain old round rings too
I count 2 high profile teams using oval rings in your link, and there are plenty of high profile riders that use them...
Brad Wiggins, David Millar, Richie Porte, Jani Brajkovic, Chris Froome, Chris Sutton, Geraint Thomas, Greg Henderson, Lars Petter Nordhaug to name a few.
Many Olympic gold medals have been won on an oval system too. There is a lot of team politics that affect what riders run etc, which we dont need to get into.
Moral of the story is: If you dont want them, dont buy them. I am stoked that round rings work for you, and I'm stoked that i have the option to run them.
Cheers!
But at high/very high cadence there is a limit to your body. Leg will simply not be able to micro accelerate more in dead spot as your big momentum from high cadence will leave the leg outside of your control. The inertia of your leg will just push it over dead spot naturally with constant speed as you are not able to react quick enough. Or another words leg will not be able to follow quick enough so you end up pedaling at the same speed. Not sure if my explanation is clear enough as english is actually not my first language.
Higher cedance vs standard 34T
The round 30 in my granny?
Dont you think if an oval chainring was so great, BioPace would have just been modified instead of eliminated?
Shimano made huge mistake and it was very hard to for them to convince people that idea was good but execution not. Same with convincing you now - in this regards nothing changed.
34-tooth Rotor 110BCD shaped road chainring
www.bikeradar.com/au/gear/article/pro-bike-ned-overends-specialized-rockhopper-sl-singlespeed-27076
RR was good for climbing, that's about it.
I did the same thing, over and over. Hard to erase what both is logical, and what one's used to. Dual control was a whole bunch of evil to anyone who moved around on their bike, like merely bunny hopping....BRAKES!
So it's no different to a regular chainring in that respect.
(chain goes faster on the taller part of rotor and slower on the lower part).
You can reproduce this effect on circular rotors by rotating cranks fast for half a rev and then slow - which is basically what happens when you ride. Mount a cam on your chainstay and you should be able to see this oscillation on bike with circular rotor.
When riding on oval rotor you will spin cranks faster on lower part of rotor and slower on higher part, thus making chain go at steady pace which won't cause the cage to move.
Summing up when spining cranks at steady pace by hand (like in the vids you linked), oval produces cage swing and circular doesn't, but in real life (when pedaling hard) it's vice versa, so addressing your concerns, the oval should be healthier for the derailleurs.
Will this work with my SRAM XX1 cranks?
www.youtube.com/watch?v=HqgR9Hq90Ts
Do they have clinical data that proves beyond reasonable doubt that it will not cause the same issues as biopace? Of course not, a clinic would cost them over $100000 (one hundred thousand dollars), without data to support something that has been proven to cause damage no longer causes damage then I for one will not invest.
its a personal choice but the risks far out weigh any potential advantage.
www.rotorbikeusa.com/images/science/pdf/sscivol06no01paper04.pdf
The fact is that they have not. You have to ask yourself why? Is it marketing, just someone tweeking something....
What will it give me.... next to nothing if anything at all.
I love looking at every reinvention of the wheel. It's up to the consumer if they buy into it.
cycletechreview.com/2012/news/oval-chainrings-good-tour-de-france
road.cc/content/feature/122089-bikes-tour-de-france
Propeleton is not a best place to look at because it all comes down to sponsoring and who pays for it - not what is best.... Only few have a voice big enough to ride some other sharpied out oval rings. Others are told by Sram/ Shimano/Campagnolo that they have to use what they are given by them or no sponsoring. Simple as that.
We face same problem in mtb. Big S's have very strict rules about sponsoring so if an athlete will use something else they will cut him off. So for smaller companies it is really hard to buy several whole drivetrains for pro riders just to promote a chainring from it. This is true for Rotor, O.symmetric or for us.
If you believe that hard that it does not work let's do experiment
Reason many people still are hesitant to try ovals is Biopace story from 30 years ago. This is NOT the same even if it's called Oval...It's like saying modern cars are rubbish because cars from 1920 year were rubbish.They have 4 wheels, steering wheel and an engine! - surely same thing, how they can be possibly better
They do not generate more power, or another words you will not generate more power. The way they work is you will be able to keep same speed you had for longer on the ride. So if you measure the time on the distance you will cover it quicker with the oval ring just because you will be able to keep constant speed for longer....
How this happens? Because ovals force you to use more muscle mass that with round rings to do same work. So they actually work less per 1cm3, and get tired to lesser extent.
You will get used to pedaling oval within 5-20min. Given that you rode round rings for many years this is nothing. But true benefits will come after 3-4 weeks when your muscles will physically adapt to it(because you now utilize more muscle mass than before and some of them may get sore for few days as they have not been used much before). Same analogy if you run 10km today and never run before such distance. Your legs will get sore for 2-3 days but then you will be able to run more.
thanks
Marcin
Only issue is that I am unfit (well unfit for me) just now, so would make natural gains anyway, I cant cycle any of the distance to work due to the snow at the moment, so only turbo and recumbent exercise bike at home are available to me.
If we wait until the snow has gone then I could do a few laps of Glenlivet over a few weeks, they would be dark/cold laps so pretty slow, not been there since June 17th's KOM lap for any real fast laps as I have not been injured properly again, so riding Dh most of the time (we are lucky enough to have some tracks near the coast with minimal snow).
www.strava.com/segments/5985777
Glenlivet currently has some trees down from the storms and a considerable amount of snow. (I would guess up to 2ft minimum).
Reading your comments here AboluteBlack, makes me see you really know your stuff and really stand behind it, and are not just copying an old design and trying to make it new by adding the n/w to it. Your knowledge and very good explanation is the part that convinved me to give one of these a try on my mtb when my current n/w chainring will need to be replaced.
Also I didn't realise that you can run this on a single speed set up without needing a chain tensioner.
The thing that I'm wondering, would this also improve for high cadense riding on flat? Like when riding on the roads or velodrome with a cadense of 100RPM?
Whole problem with Bipace was that when they launched it, it was at the top groupset (like usual) and Pros didn't like them from obvious reasons (wrong clocking etc). But Shimano kept pressing and released that into many groupsets later as well, with no option for round rings for a while. So naturally many people didn't like it and somehow put all non circular rings into one basket for such a long time. Most just parrots what they heard and never tired them...
If you want to read real testimonials look here at mtbr:
forums.mtbr.com/singlespeed/oval-rings-unfair-advantage-singlespeed-932469-24.html
there are enough people with their experience to read about.
To answer your question. As long as you have resistance on the pedals you do not feel the oval. That means if you pedal at 100rpm and still feel resistance to push more then all is good. A little bob may be noticed when you spin, but you have enough speed that your pedaling actually do not add any speed. (like when riding down). But same thing can be observed with round rings. Give a go on rollers and once you reach 120-130rpm most people star jumping on the saddle as there is not enough resistance on pedals.
It will bring very small if any benefits at very high cadence. But it will not bring any disadvantages either. Reason for that is leg has already enough speed(momentum) to "fly" over dead spot, so there is not much to improve here.
Where you see biggest benefits is where you have cadences lower than 60-70rpm which is what most people pedal at when riding in terrain (except some pro XC riders maybe).
The slower you pedal the bigger the benefit is because it helps to overcome the dead spot. As the slower you pedal the more time leg spends in dead spot - so naturally if you can improve this bit and leg goes quicker here a bit then you gain more fluidity in pedaling motion.
This is why Ovals are such a great benefit to MTB (not road bikes), but somehow were used for years only on the Road. This is also why it is hard to prove big benefits as most studies focused on the road bikes only, where the cadence is fairly high and steady (and this means not many benefits from ovals).
What I'm thinking about is that theoretically the cranks should fly faster over the dead spot, creating a bigger percentage of time where you can add decent pressure to the pedals. But no idea how that would work out in reality (if muscles can keep up well etc).
I've heard plenty of reasons from you for me to give one of your oval rings a try when my current n/w chainring on my mtb wears out.
Cheers!
Now the article claims no oscillation of the derailleur from the oval ring. Really? Physically impossible.
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