# Do ROTOR chainrings change you ?



## diegogarcia (Apr 29, 2010)

I have been running Rotor for some 15 months now and have been looking back at my bike riding over that time and concluded that I am not riding as well. Now typically there are lots of factors such as work life balance, health and so on, but the one thing I have recently started to wonder is do Rotor oval chainsets actually work ? I ask as this has me wondering. Notice a lot of pros have moved back to round rings? I seem to have aching quads 24/7 and perhaps this could be why. It has been so long since I moved them so cannot recall if the issue was there before, but just found it interesting and there could be a link.

Any thoughts?


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## velodog (Sep 26, 2007)

Put the round rings back on and see what happens.


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## velodog (Sep 26, 2007)

the mayor said:


> They have changed me.
> I was once a beautiful young woman.....now I'm an old man.


I'm willing to bet that you had more friends when you were a beautiful young woman.


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## the mayor (Jul 8, 2004)

They have changed me.
I was once a beautiful young woman.....now I'm an old man.


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## the mayor (Jul 8, 2004)

velodog said:


> I'm willing to bet that you had more friends when you were a beautiful young woman.


Hmmmm....now that you mention it....but you may be on to something
.I thought it was the Rotor Rings.......but it just might be my hairy shoulders and this strapless evening gown.
Damn you Rotor Rings! Damn you!


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## Kerry Irons (Feb 25, 2002)

*History lesson*



diegogarcia said:


> I have been running Rotor for some 15 months now and have been looking back at my bike riding over that time and concluded that I am not riding as well. Now typically there are lots of factors such as work life balance, health and so on, but the one thing I have recently started to wonder is do Rotor oval chainsets actually work ? I ask as this has me wondering. Notice a lot of pros have moved back to round rings? I seem to have aching quads 24/7 and perhaps this could be why. It has been so long since I moved them so cannot recall if the issue was there before, but just found it interesting and there could be a link.
> 
> Any thoughts?


Oval and other various out-of-round chainrings have been available for something like 100 years. Each time they hit the market (about every 15 years) they are hailed as "the next big thing." After a few years people start to notice that they don't really help and maybe they hurt. You might be on the front of the wave for that experience.


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## Ventruck (Mar 9, 2009)

velodog said:


> Put the round rings back on and see what happens.


Objectively all one can say in that case is it feels different because they're used to one ring or the other. It is an idea but I'd draw a conclusion after some good saddle time.

Being on a Rotor Q-ring for about 13 months, I'm going to vouch for them doing what they said would do in regards to clearing the dead spot better. No matter how smooth you are with a regular round ring I highly doubt that positive feeling could ever be emulated.

I did stop using it this January. Undeniably I knew I couldn't totally match the rhythmic motion I had when climbing. I had to pick one OCP or the other if I wanted to feel good either standing (4) or sitting (3). Ring can't cater to both because the "regulation point" is fixed relative to the bike, and not to the rider. In other words you can't change up how you're gonna invest the power in your stroke in various conditions. This became very noticeable on longer rides. 

The only alternative idea was to figure out a pedaling form to make things work, but in the past 13 months of riding 6 days a week with hills it never happened for me. Decided to see whether or not all that was actually true because I was less developed of a rider back then, and I only got faster by training in general...

Apparently 3 months back on a round ring and feeling at my prime. I can spin up accelerations better and generally be more versatile. There is that lagging feeling at TDC/BDC but it's somewhat sparking me to better-connect on my downstrokes.

The whole claim in regards to power is dependent on particular riding form. Carlos Sastre won a Tour de France on it with one of his major breaks being on a climb if I recall correctly. I'll just outright say though, Alberto Contador on round rings would've outdone him if he was cleared to ride that year.


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## diegogarcia (Apr 29, 2010)

Well I moved back to round rings 6 weeks back and have been riding better ever since.

In the first instance the dreaded 'dead spot' was there, but within minutes it had gone. Also, my climbing is much better as like another poster here I felt q rings where not great climbing, but good in the big ring on the flat. As an testament to the round rings, this week I climbed my worst 2 local climbs no problems - pb's in fact, but I have been getting some solid long rides in and completed 300 miles this week so riding into some nice form.

Still tough though as not a climber but much better tapping out the rhythm on round and the dead spot actually helps me count to take my mind off the road.

In conclusion I suspect being on q rings did my cadence some good, but I am more than happy back on Dura Ace round and that is how it is staying.


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## IJBcape (May 27, 2011)

Osymetric 52t seem to work well for Wiggins.


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## gordy748 (Feb 11, 2007)

If you use the ovalized ones you will grow funny sideburns, but I haven't heard of other side effects.


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## samh (May 5, 2004)

do these affect front deraillleur adjustment?


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## IJBcape (May 27, 2011)

Took me about 40 seconds to set up Q-Rings on Sram Red. It's super easy and shifts totally fine. I have not dropped a chain or had any bad shifts in front for 2600 miles on these since May. Unless you ride in mittens you won't have any trouble shifting.


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## richnmib (Dec 26, 2011)

Do you have to change both the big ring and the small ring or can you just change out the big ring? I almost never ride in the small ring and changing only one would be cheaper.


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## forge55b (Jan 30, 2011)

richnmib said:


> Do you have to change both the big ring and the small ring or can you just change out the big ring? I almost never ride in the small ring and changing only one would be cheaper.


You can change just the big ring. The small ring is only slightly out of round vs the big ring.

That said, I think front shifting suffers quite a bit but if it works substantial better for you, the benefits clearly would out weigh any negatives.


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## Stuart B (Feb 26, 2006)

Had my rotor rings a couple of weeks now and still struggling with frint shifting...chain coming over the top...try to dial it out and it won't shift into the big ring....gonna persevere with tuning though.


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## Cinelli 82220 (Dec 2, 2010)

IJBcape said:


> Osymetric 52t seem to work well for Wiggins.


Yes, and they are quite extreme compared to Rotor. I've never seen any problems except for that time trial where his chain flew off the top.

A couple of other Sky guys use them too.


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## woodys737 (Dec 31, 2005)

Interesting topic to me as I ride a 53-39 Rotor Q combination. After a couple years on them I recently rode a loaner bike for a week with round rings and found the rounds were every bit as smooth but lacked punch compared to the Rotors. I thought the smooth aspect was interesting because when I first tried rotors they felt "normal" yet when I switched back to rounds they felt super choppy. Like pedaling squares. So after years of rotors I can say that both Rotor and rounds feel similarly smooth.

As far as punch goes it's very hard to describe. I guess I felt less powerful at TDC and BDC during tempo and threshold level riding with the round rings. And while sprinting and on the rivet standing climbs the cranks felt much shorter than the Rotors. Climbing, especially max power standing, was where the lack of punch feeling was most noticeable.

Now that I'm back on the Rotors the choice will be Rotors for me. If they change the rider I don't think it is anything substantial. Perhaps a small amount of muscle adaptation but, certainly nothing that would make a rider noticeably worse off or better for that matter. I use crank based power and plan on borrowing a PT to try and verify if any difference in power while using same gearing and cadence from rounds to Rotors.


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## LO^OK (Feb 1, 2008)

diegogarcia said:


> I have been running Rotor for some 15 months now .... I seem to have aching quads 24/7 and perhaps this could be why. It has been so long since I moved them so cannot recall if the issue was there before, but just found it interesting and there could be a link.
> 
> Any thoughts?


While it is proven that non circular chain rings engage and load the various muscle groups somewhat differently our bodies are very adaptive, and thus would have been much more likely you to experience discomfort at the very beginning rather than after 15 months of continuous (I assume) riding. Not to mention that Rotor are the mildest of the ovalised chain rings.


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## LO^OK (Feb 1, 2008)

diegogarcia said:


> I have been running Rotor for some 15 months now ..... I seem to have aching quads 24/7 and perhaps this could be why.
> 
> Any thoughts?


I assume too that the rings are installed correctly. I am sure you are well aware that the orientation of the ring is crucial for the performance; wrong position would produce no gains, or even has a negative affect as was the case with the infamous Biopace.


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## Kerry Irons (Feb 25, 2002)

*Infamous Biopace*



LO^OK said:


> I assume too that the rings are installed correctly. I am sure you are well aware that the orientation of the ring is crucial for the performance; wrong position would produce no gains, or even has a negative affect as was the case with the infamous Biopace.


And yet Shimano published studies in the scientific literature showing a 3% increase in power using Biopace (untrained riders, low cadence, relatively low power output). Every out of round chainring every foisted on the public has claimed great results and they ALWAYS claim to have "fixed" the problems of the previous generation. This has been going on for over 100 years.


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## tomatogti (Jul 24, 2012)

Am very interested to read all your views as I'm considering trying non-round rings. Wondering whether I should try just big ring initially and also rotor or osymetric. Must also depend on the type of rider too. I'm a sprinter but also very inflexible (sit more upright than everyone I race against) although I do spin quite a high cadence - don't see many (any?) top sprinters using them from memory. Sorry for partially hijacking thread but interested in views but +ves and -ves of swapping.


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## wim (Feb 28, 2005)

LO^OK said:


> I am sure you are well aware that the orientation of the ring is crucial for the performance; wrong position would produce no gains, or even has a negative affect as was the case with the infamous Biopace.


It's not right to imply that Biopace chainrings were in the "wrong position." Biopace was designed to reduce power peaks. Biopace orientation was based on the reasoning that a rider brings the highest force on the pedal when the crank is horizontal, so _less_ leverage (the lever being the distance from the center of the crank to the chain) at or near that point reduces power peaks, smoothing out the power curve.

Other purveyors of ovoid rings take the opposite approach: with the rider bringing the most force on the pedal with the crank horizontal, _more_ leverage at or near that point translates into more power.

No one really knows if any of this actually works. I seriously doubt it.


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## Stuart B (Feb 26, 2006)

wim said:


> It's not right to imply that Biopace chainrings were in the "wrong position." Biopace was designed to reduce power peaks. Biopace orientation was based on the reasoning that a rider brings the highest force on the pedal when the crank is horizontal, so _less_ leverage (the lever being the distance from the center of the crank to the chain) at or near that point reduces power peaks, smoothing out the power curve.
> 
> Other purveyors of ovoid rings take the opposite approach: with the rider bringing the most force on the pedal with the crank horizontal, _more_ leverage at or near that point translates into more power.
> 
> No one really knows if any of this actually works. I seriously doubt it.


I think you have it back to front....but unsure as you don't seem to use the word power in the scientific sense (quite common, but confusing). Rotor and O-symmetric make it harder when the pedals are near horizontal...when you have more strength to pedal. Biopace made it easier near horizontal.


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## wim (Feb 28, 2005)

Stuart B said:


> I think you have it back to front....but unsure as you don't seem to use the word power in the scientific sense


Strangely enough, I know exactly what power (watt) is as opposed to force (newton) or torque (newton-meter). But you're right—the flattened curve Biopace was supposed to produce would be a force curve, not a power curve. Thanks for the correction.

As to "harder" and "easier": it's not that simple. There are four levers (L1,2,3 and 4) at work here, see sketch. The relationship between L1 and L2 is what matters in this discussion. As an aside: to the same end, there are inventions of cranks with a constantly-changing crank length (L1).

And as a challenge to all those who understand what power is in the scientific sense: invent a bike on which F1 = F4. Right now, F1 is always much larger than F4 at any kind of decent speed as you can see by the length (magnitude) of the force arrows. With F1 = F4, a 40 mph average on the flat wouldn't be that hard to achieve.

.


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## Stuart B (Feb 26, 2006)

wim said:


> Strangely enough, I know exactly what power (watt) is as opposed to force (newton) or torque (newton-meter). But you're right—the flattened curve Biopace was supposed to produce would be a force curve, not a power curve. Thanks for the correction.


Cool beans



wim said:


> As to "harder" and "easier": it's not that simple. There are four levers (L1,2,3 and 4) at work here, see sketch. The relationship between L1 and L2 is what matters in this discussion. As an aside: to the same end, there are inventions of cranks with a constantly-changing crank length (L1).


Agreed about L1 and L2...that's why non round the Chain rings have an effect



wim said:


> And as a challenge to all those who understand what power is in the scientific sense: invent a bike on which F1 = F4. Right now, F1 is always much larger than F4 at any kind of decent speed as you can see by the length (magnitude) of the force arrows. With F1 = F4, a 40 mph average on the flat wouldn't be that hard to achieve.
> 
> .


F1 is always larger for a reason...and this is where I think you don't understand power again and you are in the realms of perpetual motion....or fishing.

Power = force x linear speed or for rotary systems torque x rotary speed. 

You said that force at the tyre contact patch is much lower than at the pedal normally...true....speed at the contact patch is proportionally higher than at the pedal.

To do 40mph with a bike that had F1=F4, the pedal would need to travel at 40mph around its circle...ignoring drive train losses....with dive train losses pedal force would be slightly higher then contact patch force.....pretty sure I can't extend my leg at 40mph.


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## wim (Feb 28, 2005)

Stuart B said:


> You said that force at the tyre contact patch is much slower than at the pedal


I did? I think I said "less," as in "fewer newtons." I'm putting this to rest.


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## Stuart B (Feb 26, 2006)

wim said:


> I did? I think I said "less," as in "fewer newtons." I'm putting this to rest.


sorry meant lower....as your words and diagram...sorry for the typo


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## Kerry Irons (Feb 25, 2002)

*40 mph?*



wim said:


> With F1 = F4, a 40 mph average on the flat wouldn't be that hard to achieve.


Oh yes it would. Regardless of the forces involved, it would take 1100 watts for a rider on a normal road bike. Nothing you can do with changing lever arms can alter that fact despite what the marketing department says.

The key thing to remember about all of these devices that claim to improve power output/speed is that they either have to extract more power from the body or allow the body to operate more efficiently. Neither one of these concepts has EVER been demonstrated.


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## LO^OK (Feb 1, 2008)

wim said:


> No one really knows if any of this actually works. I seriously doubt it.



My impression is, it's quite well understood actually. At the TDC and BDC cyclist's efforts are at the most inefficient, regardless of his/her skills (to quote loosely, I've read somewhere that only about 6% of cyclist's power is used). With the exception of Biopace all other non circular rings aim at shortening the time spend in the TDC and BDC; and maximising torque by effectively varying the chain ring size.

The link contains a couple of studies; and comments of previous research.

Non Circular Chainring


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## Kerry Irons (Feb 25, 2002)

*Read somewhere?*



LO^OK said:


> (to quote loosely, I've read somewhere that only about 6% of cyclist's power is used).


Do you mean 6% efficiency during the TDC and BDC phases or overall? A lot of data shows that for a conditioned athlete, metabolic efficiency is about 24%. That translates to 3.6 "calories burned" per watt-hour. At 275 watts you're burning about 1000 calories per hour. How that might relate to your 6% number is not clear.

But I repeat: out-of-round chain rings either have to extract more power from the body or allow the body to operate more efficiently. Neither one of these concepts has EVER been demonstrated.


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