Pinkbike Poll: Oval Chainrings?
Absolute Black's 32-tooth oval chainring on a Shimano XTR 104mm bolt-circle crankset.
Oral tradition and the written word states without question, that experienced cyclists pedal in perfect circles, and that doing so ensures every muscular contraction which occurs in the braided musculature of the rider’s legs is efficiently converted into forward motion. The analogy of a smoothly balanced piston engine is often used to describe the cadence of professional cyclists in action. Inexperienced cyclists, those who have not attained such mastery, are jeered because they “pedal in squares.”
Cycling science, as it presently stands, supports the sacred circular stroke, but before we believe every sports doctor’s advice and take their revered training manuals as gospel, we should consider that most of the research which upholds the perfect pedal circle was generated by old-school cyclists who were established believers. Have presumptions poisoned the science of cycling? Could it be possible that after seeking the perfect pedaling circle for one and a half centuries, that cycling got it wrong? Could there may be a more efficient method of pushing pedals around a crankset?
With practice and determination, a healthy human body can be successfully taught to master a wild range of physical activities and repetitive motions. Those who need proof need only to watch Eddie Van Halen play guitar, attend a circus, or take in a Bikram Yoga competition. Pedaling in perfect circles should seem laughably easy after that trio of performances – so, why is it so hard?
Both are 32-tooth chainrings and both will drive the bike forward at the same speed at a given RPM.The Absolute Black Oval sprocket can actually smooth out your power stroke during high watt efforts.
The answer may be hidden in the first paragraph of this intro. Perhaps the reason that newbie cyclists pedal in squares is that the human body was not designed to pedal in perfect circles. Perhaps today’s most elite cycling professionals could benefit by deconstructing their “perfect” circular pedaling and adopting a motion that favors human kinematics that evolved over millions of years for walking and running upright. As it is with all idealized forms and philosophies, reality and truth can always be found somewhere in the middle.
Bionicon's B Lab oval chainring uses a less exaggerated
oval shape. The narrow-wide tooth profile is a must.
Widespread acceptance of one-by drivetrains has created an opportunity to re-evaluate conventional pedaling logic. There are a growing number of riders and component makers who believe that oval or cam-shaped chainrings should be used to better match effort required to turn the cranks with the kinematics of the human skeleton and musculature. Asymmetrical and oval chainrings have been in use for quite a long time and have earned victories in every form of cycle racing with the possible exception of DH.
OEM drivetrain suppliers, however, have not participated, primarily because reliable shifting is a struggle for even the best front derailleurs when the diameters of the sprockets are constantly changing. But, the recent domination of one-by drivetrains and their companion, the SRAM-developed narrow-wide tooth profile, have eliminated the need for a front changer and also paved the way for OEM drivetrain makers to experiment in earnest with asymmetrical chainrings.
OEM drivetrain suppliers, however, have not participated, primarily because reliable shifting is a struggle for even the best front derailleurs when the diameters of the sprockets are constantly changing. But, the recent domination of one-by drivetrains and their companion, the SRAM-developed narrow-wide tooth profile, have eliminated the need for a front changer and also paved the way for OEM drivetrain makers to experiment in earnest with asymmetrical chainrings.
The concept of optimizing a mechanism to operate in a non-linear mode that more closely mirrors human kinematics has been successfully employed in other areas. Cam-driven weight machines and high-power compound archery bows are two examples that pop into mind. I counted a half-dozen aftermarket drivetrain suppliers that offer asymmetrical chainrings for road - and beyond Rotor, the Spanish pioneer that has been the point of the spear for their development - at least four more brands have jumped into the mountain bike arena with oval or asymmetrical rings.
Rotor learned that adding timing options to its chainrings
was an essential tool which allowed riders to tune the
sweet spot to their pedaling styles.
Mountain bikers, haunted by the ghost of Shimano’s asymmetrical Bio-Pace chainrings which plagued early mountain bikes will no-doubt resist the mere mention of a chainring that is not round, but times have changed. Powermeters and other devices that track and measure riders’ watt outputs and real-time cardio-vascular data are commonplace, and cyclists regularly use those tools to personally evaluate performance items. Seeing is believing. Presumably, the popularity of asymmetrical chainring among elite road racers is also directly related to the fact that most race and train with power meters, so they can measure results and eliminate guesswork and presumption from their performances.
At present, most offerings for mountain bikes are simple ovalized sprockets, a handful of which, Pinkbike is presently testing. Initial impressions are that the concept is not perfected, but it has legs. There is a learning curve required to time your cadence to the pulsing effect. Speed remains about the same - the bottom line is that, round or oval, one revolution of a 32-tooth sprocket still advances the cassette by 32 teeth. The difference felt is in how the legs mete out pressure on the pedals through the crank circle, and it seems to help most when laying down lots of torque.
At present, most offerings for mountain bikes are simple ovalized sprockets, a handful of which, Pinkbike is presently testing. Initial impressions are that the concept is not perfected, but it has legs. There is a learning curve required to time your cadence to the pulsing effect. Speed remains about the same - the bottom line is that, round or oval, one revolution of a 32-tooth sprocket still advances the cassette by 32 teeth. The difference felt is in how the legs mete out pressure on the pedals through the crank circle, and it seems to help most when laying down lots of torque.
Ultimately, the basic oval will probably evolve into a more optimized shape - which is what the more experienced players, like Rotor and O,Symetric, are already doing. Ironically, the evolution of the asymmetrical chainring is leaning towards a slightly rectangular profile – which suggests that the human body actually is designed to pedal in squares.
So, the question for today’s Pinkbike Poll is: If it could be proven without a doubt that using an asymmetrical chainring would improve your pedaling output or efficiency, would you switch over from round rings?
Where to look for asymmetrical chainrings: Rotor Bike, Absolute Black, Bionicon B-Ring Oval.
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on the other half you will have the acceleration and weight of a 26er. you can also round that up. again 100% of the wheel
so in the end you will have a wheel that is 200% better.
trust me, i`m a sciencer
on the other half you will have the acceleration and weight of a 26er. you can also round that up. again 100% of the wheel
so in the end you will have a wheel that is 200% better.
trust me, i`m a sciencer"
You forgot to mention that you will have a awesome feeling of pump track, and will boost your skill and power like on pump track.
Really it would be the best of all 3 worlds.
If you're going to test which ring is better then you need a machine providing a constant force to the cranks, then measure the power output. An actual person can't be relied upon to provide a constant cadence/force to cranks for this test
If a machine does it then there will be no difference. The entire point is that humans don't provide a constant force to the cranks.
If you're testing anything else it's not right to use people for the test.
"The slight tendency towards improvement in power output when using the oval Q-rings (increase of 2.5–6.5 % relative to circular chainrings) suggests that Q-rings could result in slight improvement during on-road cycling performance."
www.ncbi.nlm.nih.gov/pmc/articles/PMC3990898
IMHO, we can't stop it. We must accept the developement.
Please let me ask y'all this. Why y'all choose a modern DH bike rather than Klunkers?
My fams told me this "You will never know before you try."
The worst word that people really fear is "Change". Yes, i must admit i hate changes. But, why not change for a better thing.
I'm not saying this asymetric / oval chainring is great. Because i haven't try it.
Indeed, nowadays bicycle industries make a ridiculous price for their products.
I have a friend in Taiwan (where BIG names in bike industry make their carbon bike) and Japan who work in that HUGE bike components industry.
They said the original price for each product is WAAAAAAAAAAAAAY below the MSRP price. Especially for a carbon frame.
For example, a carbon hardtail bike w/ top notch components will cost you at least US$2-4k. CMIIW.
The original price would be around US$400-700.
@PLC07 hey man, if you're not happy with their price, don't buy it. But, if you think the price tag is worth with what they offer to you, IMHO at least consider it. Simple as that.
Me too, if i think i don't have that paper to buy their product(s), i wouldn't buy it.
Best regards.
ep1.pinkbike.org/p4pb8900868/p4pb8900868.jpg
Speaking to the customers they definitely found improvement in their times, after developing a different pedalling style to work with the oval rings. Customers said all of their bikes (many had multiple bikes) had to be switched to oval rings, because they could not tolerate running round rings on 1 bike and oval on the 2nd bike.
Have "ridden" a few bikes with ovalised rings, not owned and changed my pedalling style, so cannot comment with authority on the effect on a rider myself?
Complication, hype? That thing takes exactly same money to make and 4h of CADding more to draw than a perfectly round chain ring. Yes it will feel different, but not as much as changing from a round 32t chainring to a round 34t chain ring. If suddenly someone declares that the whole industry will be running those then i could not care less. What? Does it pollute a river in China?
Look someone just made something it is an oval chainring - nothing - still nothing - yaaawn - faster, quicker - aaah - brrrp - it's gone...
What gets to me is people jumping the "OMG ULTIMATE REVOLUTION!!!!!!1111eleventyeleven!!1!" bandwagon before a product has proven its claims and then proceed to castigate those who show a healthy dose of skepticism. I understand that most of it is clickbait but I can't help feeling like it is lazy "journalism" at best.
*Doesn't include shipping fees.
What we need is consistency. And I think that is best found with a circular chainring.
Oval chainrings might be worthwhile in other forms of cycling but I don't think its gonna help on a mtb, in fact I think it would create a disadvantage if anything.
Setting that aside though, maintaining traction in the dirt can often be about keeping even torque output, big spikes cause the rear tire to break free(lots of roadies have problems with this when they first try riding in the dirt, because road riding doesn't punish you for uneven power output.)
I'm not convinced that making your torque output even less symmetrical is a good idea. I'm sure RC can compensate, but this sounds like a way to make cleaning a tricky climb even harder for a newbie.
The issue with this is that it gave the most resistance in the part of the stroke that you have the least power. Modern elliptical rings (which funnily enough are more similar to the very first elliptical rings than Biopace) do the opposite, and give you the most resistance at the point where your body can naturally generate the highest force, and a lower effective gearing in the regions where you can't put out as much torque.
BTW, I love how all the people who like them are content to harp on how much greater they are, without addressing specific points about them like the one I keep bringing up: I take abbreviated pedal strokes, in order to clear obstacles. having differing levels of resistance at different points in my pedal stroke isn't something that sounds like a great idea in that respect.
Not all oval rings are created equal: They need multiple mounting positions to time the pedal stroke. depending on your bike fit/anatomy, you apply power in a slightly different spot.
For me, they have helped the most on steep climbs, where you may be overgeared(especially with a single ring) and keeping traction on the back end is difficult. The "easy" spot in the pedal rotation sort of guides your foot underneath, setting you up for your next stroke.
Not the same as Biopace. The timing is complete opposite.
Seems to me they are more useful on mtb than road, but ive only tested the road setup briefly.
They aren't going to give you free power or any silly shit like that, but if you try them you might be pleasantly surprised by how they feel.
a) Ad copy
or
b) Completely incomprehensible (like today's story).
To help you out... He simply questioned optimal human kinematics in respect to pedaling and wrote a concise history, including the present direction of the tech. Commentary in the article was minimal and definitely not (blatantly) opinionated. What is so difficult to comprehend?
In my opinion, it is well written. It was a neat little story with just enough info and something to think about. I especially like how he tied "square pedaling" into the beginning and end.
If they have any benefit what so ever, I'm open to running one of these rings. But please, make them compatible with a bash ring because they are frack'n ugly.
My overall comment, as stated in the first sentence, was related to his writing as a whole. The "incomprehensible" comment was directed at this specific story. Does that help?
What gets to me is the massive hype about just anything new. I understand everybody has to sell their stuff and that the marketing dept has to justify their jobs but take this ring for example, it hasn't even been proven to do anything so far. Some people (and studies) say it does, and some say it doesn't. Even if it does, for the average pinkbike user, is it going to be enough to make an actual difference in their riding?Is the media that desperate to get any sort of news headlines? I understand that the possibility of a 1-5% ish performance gain would be very appealing to the road crowd but here? (..)
I first found the oval ring concept somewhat interesting when it was featured in one of the bikeshows articles and I was curious to see how far this concept would go (knowing biopace's previous failure) but now I'm just hoping it's not going to turn into another marketing mess like some of those we've seen recently.
It is a mistake to consider that asymmetrical rings are comparable:
- first BioPace had an opposite design to the other non circular rings because it relied on dynamic rather than static leg position. The idea was to lower the diameter where the leg is trong to provide acceleration and "help" going through the dead spot quicker. This design proved to be wrong and has actually nothing to do with most modern design.
- second, all asymmetrical rings are not equal. Rotor makes barely oval rings which do not provide significant difference IMO. Also the position of the big diameter is crucial and differs between designs. Some rings such as Ogival have a very exaggerated shape that (apart from gerashifting issues) feels wrong under the leg. There is a sweet spot to reach and no commercially available design out there is perfect at the moment. In my experience however, I can tell that Osymetric is by far what is the closest to the perfect design.
It is striking that most asymmetrical designs are in majority used by roadies or triathletes while I do thik they offer maximum benefit for MTB only. These rings are of course of little to no use for DH. Despite some wild claims in terms regarding power gain from manufacturers, the advantage resides more in the fact that your muscles will fatigue less and offer benefits for long XC/AM rides mostly. I also do see that I am able to fuel through higher cadences on climbs.
Overall I couldn't think of going back to round rings because they feel much more natural under the pedal than standard rings. Would be cool if some science can prove their benefits but the thing is there are many poorly designed oval rings out there that just f*ck up the concept. One has to carefully choose when purchasing...
wonder if they might affect rear suspension or the clutch in a rear mech? seeing Froom's driveline at high cadence is whack and how that would go on a long/med travel trail bike?
i think that makes sense.
BTW, wasn't trying to be argumentative, its just interesting!
A discussion for the sake of its own and producers doing their politics alone.
I still don't really understand the point of your poll question still. If something proves to be better, many people will switch to it over time. In this case the "proving" is going to be difficult. I agree with you that the discussion is worthy, but your poll question pretty much backs people into a corner, hence predictable massive single bar in the poll.
High pivot suspension with chain pulleys are better without a doubt, but there is not many DH frames with chain pulleys.
Two connondale lefties creatig a whole fork, with 200mm travel and good internals would be without a doubt the ultimate fork, but it simply don't exist.
So, something "proven without a doubt" is not always the only way to go.
The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. evertheless, we are unaware of any scientific studies that have examined the performancebenefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclistscompleted, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion ofthe study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or eitherelliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.
Most of them say that there is little to no difference. The ones that do affirm that it makes a difference only make the claim for professional athletes AND over a long course. My conclusion: Unless you are in the top 1% of all athletes... move on.
Bio pace may be good for some but I hated it back it in the day. I like the smoothness over the pronouncedup and down feeling of the oval.
If the industry orders a code red on round rings like it did on 26" wheels, that will be a sad day.
As the chain grows its going to pull on the mech until the clutch lets go.
So every time you spin the cranks you wasting energy on the clutch.
Wiggins and Froome use(d) the oval chain rings and they have both won the Tour de France.
skip to 2:10 pretty interesting
www.facebook.com/video.php?v=505979186171418&set=vb.115426098560064&type=2&theater
If you say like that without any official and scientific lab test result, you have no right to say it.
IMHO, we can't stop technology developement.
Did you see what Fab Barel use for his strive CF on finale ligure?
open this link -> www.vitalmtb.com/photos/features/WINNING-BIKE-Fabien-Barels-Canyon-Strive-CF,8214/Slideshow,0/sspomer,2
It is indeed interesting stuff.
Honestly, i want to try it.
www.vitalmtb.com/photos/features/World-Champs-Fabien-Barels-Tweaked-Mondraker,202/Slideshow,1643/sspomer,2
www.pinkbike.com/video/343829