# QRings vs. o.symetric



## rs_herhuth (Aug 17, 2009)

Im buying into the non-round chainring concept. The physics make sense. I was wondering which way to go, Rotor Q-Rings or O.Symetric's.

The O.Symetrics appear to be more agressive and my initial thought is that if Im going to go this route, I think I should go the more extreme route.

Thoughts? (riders that have ridden both comments would be greatly appreciated)


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## Marc (Jan 23, 2005)

Why not BioPace or any of the other dozens of incarnations that "finally got it right" that came in the 100 years prior since the first patent on non-round rings?


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## rs_herhuth (Aug 17, 2009)

Biopace was designed to lessen knee pressure not for perfomance, so thats not what Im going for...but thanks for playing.


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## Marc (Jan 23, 2005)

rs_herhuth said:


> Biopace was designed to lessen knee pressure not for perfomance, so thats not what Im going for...but thanks for playing.


No, they were designed for performance and being easier on the knees is only a side effect. Per Sheldon Brown "This is because the Biopace design is based on a dynamic analysis of the motion and momentum of moving cranks and legs, unlike the static, geometric analysis that produced classical ellipticals." There's a nice section on the voodoo of non-round chainrings and the supposed "deadspot" in Bicycling Science 3rd Edition by Brown.

Every generation claims to fix the obvious fatal flaw in the things....and every generation fails to catch on in a sport where people count every single gram.


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## Chris Teifke (Aug 11, 2012)

A friend of mine tried both, he seemed to like the O.Symmetric better by a mile.


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## AndreyT (Dec 1, 2011)

rs_herhuth said:


> Im buying into the non-round chainring concept. The physics make sense. I was wondering which way to go, Rotor Q-Rings or O.Symetric's.


The whole story reminds me of an old anecdote about Lev Landau (they way I heard it first, although there are probably versions of the story with every known physicist in his place): A student once asked him to explain some graph outlining results of some physical experiment. Landau immediately came up with a perfect explanation. At that point the student suddenly noticed that the graph is upside down and the actual results were the opposite of what they appeared at first. Landau turned the graph around and casually produced a perfectly logical explanation of the new results.

The same thing seems to take place with oval rings. There are two systems out there, one is practically opposite of the other: one is narrowest at the crank (or near it), designed to maximize static driving force on the down push (Rotor); another is widest at the crank (or near it), designed to improve the efficiency of momentum usage (BioPace). Both offer a perfectly credible physical explanation of why it should be done that way specifically


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## Stuart B (Feb 26, 2006)

Q-Rings are slightly out of round and its a linear transition. I now ride Q-Rings to see if helps my dodgy knee. O-Symmetric are more extreme and also have non linear transitions. I haven't ridden these though.

Front gear shifting performance is affected.


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## den bakker (Nov 13, 2004)

Stuart B said:


> Q-Rings are slightly out of round and its a linear transition. I now ride Q-Rings to see if helps my dodgy knee. O-Symmetric are more extreme and also have non linear transitions. I haven't ridden these though.
> 
> Front gear shifting performance is affected.


well according to one poster you should have opted for the bios then


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## rs_herhuth (Aug 17, 2009)

I stand corrected on the Biopace argument, but regardless Im not considering Biopace.

In cycling repetition of movement is paramount. It is the cumulative effects of economy of motion and the bodys ability to adapt to a range of modifications that only become apparent over extended periods of time.

I have read posts where some users say there is no difference once you are used to either. Some say they lower your heart rate for the same effort. In a sport where endurance is king, any modification made to economy of motion seems like it would create benefit.

I see other forum posts where riders argue over paying hundreds of dollars to shed 100 grams, when o bowel movement before a ride sheds more than that. So why not focus on spending a couple hundred bucks on the biomechanical aspect of cycling.

To each his own, and I might come to the conclusion these wont work for me. I dont give a crap about graphs supporting or denying the effects of tweaks, hell science cant even make up their mind if eggs are good for us or not. I just want to see if an edge can be gained to my performance by trying out-of-round rings. Whether or not you support the thought of if it works dont fix it... That is a topic for another day. Im intrigued at the thought of potential economy gains, now I just want to make up my mind on how much


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## den bakker (Nov 13, 2004)

rs_herhuth said:


> I stand corrected on the Biopace argument, but regardless Im not considering Biopace.
> 
> In cycling repetition of movement is paramount. It is the cumulative effects of economy of motion and the bodys ability to adapt to a range of modifications that only become apparent over extended periods of time.
> 
> ...


so the physics make sense but you don't give a crap about data supporting or denying the effects? 
To each his own. Just be careful, the asymmetric chain rings may cause havoc on power bracelets due to the strong high order magnetic fields due to the non-circular geometry. :thumbsup:


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## Stuart B (Feb 26, 2006)

den bakker said:


> well according to one poster you should have opted for the bios then


Not if you think lowering forces on the knee at the top of the stroke rather than horizontal is required


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## Ventruck (Mar 9, 2009)

I've used Q-Rings. Do work as suggested but ultimately didn't like them. And yes I will say they work differently (literally the opposite) than Bio-pace.

And as bias as it sounds, if you were to try one or the other, I'd pick Rotor for the reasons opposite of why you think you should go O.symetric. Radical change isn't safe measure. 

And skimming through the more recent O.symetric USA website, they have even more outlandish claims than Rotor (higher gains). The "twin-cam" shape is too radical complex to understand conceptually you're just left being hopeful it does anything. Rotor even accepts that people may prefer round rings and offers their own.


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## CycoBob (Aug 1, 2012)

Seems to me, that what you would gain (with any non-round ring) on one part of the stroke, you would lose in another arc of the circle. Seems like it'd be a zero net sum. You can isolate the data to just emphasize the good parts, and make anything look good/'advantageous/plausible.


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## looigi (Nov 24, 2010)

Yep. The physics may make sense, but the physiology of pedaling is much more complicated. Elliptical chain rings and many other variations on trying to optimize pedaling motion have been around for 100+ years. In objective power testing, none have been shown significantly or reliably effect power output or efficiency. Even changing crank lengths over a wide range had little effect. Basically, it comes down to a subjective preference.


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## LO^OK (Feb 1, 2008)

rs_herhuth said:


> Im buying into the non-round chainring concept. The physics make sense. I was wondering which way to go, Rotor Q-Rings or O.Symetric's.
> 
> The O.Symetrics appear to be more agressive and my initial thought is that if Im going to go this route, I think I should go the more extreme route.
> 
> Thoughts? (riders that have ridden both comments would be greatly appreciated)


I wouldn't term O.Symetric as "aggressive" or "extreme", it is just a non compromise design that managed to prove it's excellence despite road cyclists' mindset rigidity and the corporate sponsors fierce resistance (even without the logos it's shape is instantly recognizable). 

In contrast the Orings were conceived to be as inoffensive as possible for the ease of marketing. According to many studies it's the least effective design currently on the market due to the minimized ovality (around 10%). For comparison, the designs considered the most effective at the moment (O,Symetric and Ogival) have ovality between 20 and 40%

The interesting side of the non-circular designs that rarely get discussed is the biomechanics. Firstly, more muscle groups become engaged, and get to be loaded differently when compared to what happens when cycling with round chainrings. Hence the less fatigue after some adaptation period.

Secondly, apparently the concept of Top and Bottom DP is not that simple when applied to cycling. Due to the two points of actuation (the hip and the knee joint each of which has it's own TDP and BDP) will be more correct to speak of zones before and after 12 and 6 o'clock of diminished effectiveness. Obviously the exact spread of the zones would depends on the individual's anatomy and the bike geometry; according to one study we are talking in the range of 17° of each side of the TDP and BDP.


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## foto (Feb 7, 2005)

since this got bumped I would add that biopace is the most awkward and uncomfortable thing ever invented.

LOL at how people quote Sheldon Brown like he's a god, the dude had Biopace on a FIXED GEAR!!!

He was definitely out there...


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## woodys737 (Dec 31, 2005)

foto said:


> since this got bumped I would add that biopace is the most awkward and uncomfortable thing ever invented.
> 
> LOL at how people quote Sheldon Brown like he's a god, the dude had Biopace on a FIXED GEAR!!!
> 
> He was definitely out there...


Awkward=power cranks. Good lord those things are pure tortue. Tried a friends years ago for a mile or two and never thought about trying them again.

My pops has biopace on an older bike. After a few minutes they feel like every other bike I've ridden. Maybe I can't feel sh!t like most...

I ride rotor rings with a quarq now and all I can say is it has been interesting finding my OCP for each ring. Huge difference between position 1 and 5 in feel and power. Have not tested power against round rings since adapted to the rotors. When I have some time to waste I'll get on it.

Interestingly, when I first jumped on the rotors they felt normal. Going back to round rings felt like pedaling squares for the first minute or two. Then everything would even out. Now after a year on the rotors when I jump on a buddy's bike with round rings I can feel no difference. 

Just thought I'd add to the confusion. Carry on....


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## LO^OK (Feb 1, 2008)

*I wouldn't touch anything Rotor*



rs_herhuth said:


> Im buying into the non-round chainring concept. The physics make sense. I was wondering which way to go, Rotor Q-Rings or O.Symetric's.


Btw, I wouldn't touch anything Rotor, whatever it's fine points, for the following reason. From the except from their FAQ bellow is obvious they have no qualms about spreading lies about their (successful) competitor: 

"How are Q-Rings different than other non-round rings such as Biopace and O.SYMETRIC?
Rotor Q-Rings help to minimize the time spent in the dead spot while pedaling. While oval chainrings have historically been controversial, we believe that allowing a rider to fine tune the chainring position offers opportunities to minimize the dead spot never before realized with conventional chainrings. The Q-Rings are elliptical; the Biopace and O.SYMETRIC chainrings are asymmetrical. The specific elliptical shape of the Q-Ring provides a very smooth uniform pedaling stroke; there is no sudden acceleration movement. Biopace chainrings are designed so that the maximum equivalent tooth size is at the dead-spot. Q-Rings have the minimum equivalent tooth size at the dead-spot which enables you to pass through the dead-spot quicker and with less stress to your knees.... "

Rotor Bike Components


O'Symetric being "asymmetrical" is a complete nonsense of course. Much more importantly, however, is the linking in the same sentence and in the same passage of the two products: their successful competitor, and a commercially dead and discredited concept. This is a dirty trick from politics and the PR industry used to manipulate, disparage and slander. I find such a practice disgusting and will not support a business that resort to that. It speaks of serious lack of ethics, lack of collegiality, and sooner or later will be experienced first hand by their customers.


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