Oval chainrings are back?

[Hilltopperny]

Originally Posted by martl

Oval rings and similar inventions will never go away because riders will always gladly embrace anything that is promising to give them the odd 1% more, and no one is more ready to accept a fairy tale.
(That englishman who won the TdF did so both with round and oval)

There is a more advanced, mechanically guided, system currently available which should make much greater gains using the same/a very similar kind of principle, its called "cyfly".
Independent measurements showed *no* factual gain at all. It doesn't stop the very entusiastic user reviews.

I was skeptical about the oval ring, but it was recommended by Scott at No22 all of the mechanics and owner of the lbs as well. All of which had these rings on their personal bikes. All the bikes are cx, gravel or mountain 1x setups.

Maybe it's placebo? I am not using any measurable scientific data as I don't ride with a power meter or even GPS, but it does feel like a smoother pedal stroke to this masher.

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[Tony]

I ride with a friend who only mtbs using a single speed. He's been mtbing using single speed for the last 20 years. He said going to an oval was like cheating?
I personnel have oval rings on both rode and mtb and really have not noticed an advantage.
Also, I hear often that oval rings don't shift well. In my experience ovals shift just as nicely as their round counter parts.

[redir]

I had Biopace on my Shogun in the 80's. But the young guy I met this year with the new oval system said, 'but it's different this time.'

[prototoast]

Originally Posted by redir

I had Biopace on my Shogun in the 80's. But the young guy I met this year with the new oval system said, 'but it's different this time.'

Biopace chainrings were oriented differently with respect to the crank arm than the newer oval options are. It is very different now.

[Mark McM]

Originally Posted by Wayne77

This might not need saying but oval rings in the 80’s and oval rings now are not the same thing. The long axis of the oval or I should say ‘decidedly not round’ shape is aligned to the pedal stroke completely different with the rings today. That’s why Biopace was horrible and why the non-round rings today have plenty of adopters. Biopace had the mechanics/leverage all wrong.

Yes, Bio-Pace is different from contemporary oval chainrings (like Rotor Ossymetric), but they both have one thing in common: Neither one allows a rider to produce more power or speed:

http://trstriathlon.com/elliptical-c...wont-let-them/

[BobO]

Originally Posted by Mark McM

Yes, Bio-Pace is different from contemporary oval chainrings (like Rotor Ossymetric), but they both have one thing in common: Neither one allows a rider to produce more power or speed:

http://trstriathlon.com/elliptical-c...wont-let-them/

“Our study had many limitations. There were some things we couldn’t look at, and so there are more places to look.”

I'd still like to see a lot more research done on it to fill some of those gaps. I recently put Absolute Black rings on my TT bike and it "feels" smoother for me. My limited available data, HR, power and RPE also seems to corroborate that I'm producing equal or better power for less physiological cost. That could all be in my head, or it could be that the different motions in the joints encouraged me to correct a flaw, my ass dyno could be in need of calibration. It would be useful to have more higher level research to review.

[Spoker]

Originally Posted by AngryScientist

Damned if I can tell the difference. I have oval rings on my bike and if I didn’t look down and see I would never know the difference between them and round.

I find this so hard to believe on flat roads because there it feels so different coming of rounds.
The fact I do not notice them on the climbs, but do notice the rounds on the climb when I change back, is prove enough for the benefit for me.
All my rides involve climbing anyway.
There seem to be more manufacturers available , which made me re-think the benefits.

[93KgBike]

Unfortunately, there has been a fair amount of experimental design around the question. But that has not kept me from running a 46t Biopace ring on my cargo bike.

A comparison of muscular mechanical energy expenditure and internal work in cycling. S.A.Kautz, M.L.Hull, R.R.Neptune. 1994

Abstract

The hypothesis that the sum of the absolute changes in mechanical energy (internal work) is correlated with the muscular mechanical energy expenditure (MMEE) was tested using two elliptical chainrings, one that reduced and one that increased the internal work (compared to circular). Upper and lower bounds were put on the extra MMEE (work done by net joint torques in excess of the external work) with respect to the effect of intercompensation between joint torques due to biarticular muscles. This was done by having two measures of MMEE, one that allowed no intercompensation and one that allowed complete intercompensation between joints spanned by biarticular muscles. Energy analysis showed no correlation between internal work and the two measures of MMEE. When compared to circular, the chainring that reduced internal work increased MMEE, and phases of increased crank velocity associated with the elliptical shape resulted in increased power absorbed by the upstroke leg as it was accelerated against gravity. The resulting negative work necessitated additional positive work. Thus, the hypothesis that the internal work is correlated with MMEE was found to be invalid, and the total mechanical work done cannot be estimated by summing the internal and external work. Changes in the dynamics of cycling caused by a non-circular chainring may affect performance and must be considered during the non-circular chainring design process.

[dnc]

Originally Posted by Mark McM

Yes, Bio-Pace is different from contemporary oval chainrings (like Rotor Ossymetric), but they both have one thing in common: Neither one allows a rider to produce more power or speed:

http://trstriathlon.com/elliptical-c...wont-let-them/

Round rings will allow a rider apply the same high torque at 12, 1, 2 and 3 o'c, if you let them. How is that torque generated, with this simple adjustment in technique around TDC,
https://www.facebook.com/watch/?v=301204007442681

That's why he has no dead spot sector in his pedalling,
https://www.youtube.com/watch?v=7hh2DcgpnkU

[Spoker]

Originally Posted by 93KgBike

Unfortunately, there has been a fair amount of experimental design around the question. But that has not kept me from running a 46t Biopace ring on my cargo bike.

A comparison of muscular mechanical energy expenditure and internal work in cycling. S.A.Kautz, M.L.Hull, R.R.Neptune. 1994

But even if all performance parameters are even, I find the strain on my low back less with the ovals. This means a increase of performance (in my case after 40 minutes climbing).

[Tabl10s]

Originally Posted by Hellgate

I swore them off on the '80's. Just say, No!

Bio-Pace felt strange as my knees would "drop" with each revolution. When I switched back, it was equally odd(Suntour even had the audacity to offer "Round" rings for sale after BP started to fall out of favor).

I now have two Quarbon Q-Rings and three round and don't feel a difference.

[Tabl10s]

Originally Posted by Elefantino

Also used Biopace ("bee-o-pa-chay") in the 80s. Stopped using them around the time I stopped wearing jean shorts.


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What are they called?

[Elefantino]

Originally Posted by Tabl10s

What are they called?

My jean shorts? I don't remember.

[makoti]

Originally Posted by Tabl10s

What are they called?

Originally Posted by Elefantino

My jean shorts? I don't remember.

They call them...Mr Norris.

[martl]

Originally Posted by dnc

Round rings will allow a rider apply the same high torque at 12, 1, 2 and 3 o'c, if you let them. How is that torque generated, with this simple adjustment in technique around TDC,
https://www.facebook.com/watch/?v=301204007442681

That's why he has no dead spot sector in his pedalling,
https://www.youtube.com/watch?v=7hh2DcgpnkU

Torque is the least significant thing that would need improving, because of a moving bike's inertia. The same goes for the so-called "dead spot" at the 12 o'clock position.

It also is a myth that that improving "pedalling efficiency" would cause an effect on riding performance.

Physiological Responses during Cycling With Oval Chainrings (Q-Ring) and Circular Chainrings. (Cordova A1, Latasa I2, Seco J3, Villa G4, Rodriguez-Falces J2.)

"During the incremental exercise test, no significant differences were found in power output, oxygen consumption or heart rate between oval "Q-rings" and conventional chainrings.Over the course of the incremental test, blood lactate levels were comparable for the oval "Q-rings" and conventional chainrings.During the short sprints performed after the incremental test, there were no statistical differences in power production between oval "Q-rings" and conventional chainrings."


"Cycling efficiency is related to the percentage of Type I muscle fibers" (EDWARD F. COYLE, LABROS S. SIDOSSIS, JEFFREY F. HOROWITZ, and JOHN D. BELTZ)

"We previously observed that cycling economy (i.e., W.I-1 VOz.min-l; seeTable 3 of ref. 5) can vary greatly in a group of well-trained cyclists. It was clear, however, that these differences in cycling economy were not due to differences in cycling technique, evidenced by various biomechanical data derived from the use of an instrumented pedal dynamometer (5)."