Osymetric Chainrings ( Giro Spoiler)

[PETER REID]

David Millar won the final TT today in the Giro using a set of Osymetric chainrings. Does anybody have any constructive comments about these? Are they the wave of the future or merely a passing fad?[COLOR=DarkSlateBlue]

[bfd]

Biopace.....

[firerescuefin]

Biopace.....

Another ignorant biopace commment...no not Biopace. Go to their site and the science is pretty sound. I ride Rotors and have been very happy since switching over.

[jpw]

I notice that the individual time trial is the penultimate stage of TdF 2011. If El Conta is under pressure would he switch to O rings? Would SRAM allow it? Will Wiggins clean up as in Bayern Rundfahrt?

[Louis]

Another ignorant biopace commment...no not Biopace.

Do we have to be quite this aggressively dismissive when disagreeing with a fellow forumite?

Have a nice day. :)

[bicycletricycle]

did you ever look at the research that went into biopace? serious research of the same nature went into it so i dont really see how one can be more valid than the other (at least as a concept). If you think that rotor rings are good than you have to accept that they are in a long line of non round rings that also include biopace, what is wrong with that? Comparing rotor rings to biopace is a compliment, it is like saying "i knew your grandpa and he was a good man, in fact he was a visionary", just because biopace was a commercial failure does not mean it was not well thought out or good.

As cyclists we cannot provide constant power through the entire pedal stroke, it is logical to try and adapt the drivetrain to match this.


Another ignorant biopace commment...no not Biopace. Go to their site and the science is pretty sound. I ride Rotors and have been very happy since switching over.

[ultraman6970]

+1...

interesting chainrings, wonder how well they do compared with the old biopace.

[fourflys]

I gotta say, I've been riding my '86 Bridgestone I found and I kind of like the Biopace compared to my new Chorus chainrings... might have to look into the rotor stuff...

Sheldon Brown says the Biopace was just really badly marketed... of course Grant Peterson doesn't like them so that means everybody else should... ;)

edit- Sheldon link in case you're curious... http://www.sheldonbrown.com/biopace.html

[dekindy]

Do we have to be quite this aggressively dismissive when disagreeing with a fellow forumite?

Have a nice day. :)

No disagreement there just acknowledging an off the cuff, uninformed, thoughtless reply with no redeeming value, not even humor.

[bobswire]

I use bio-pace on two of my commuters. I find them to be very efficient when I get into a rhythm so I would imagine they'd be good for TT. It is a different feel and takes awhile to get use to.

Millar may have won anyway but those 7 seconds he saved over his rival may be attributed to the rings?

[ultraman6970]

Well, millar was using probably 54x13 or 12 in some places, thing that really justify the oval chainring and increment in torque, but for daily use or regular road racing the biopace was just a really bad idea. Pace keeping is something that can be learn tho.

People who has problem keeping the pace, people that is really bad climbing and people that can't move legs fast like contador for example. Biopace is a big idea because helped them to overcome the dead moments while pedaling.

Used it back in the day when it came out, used it week and a half and I changed it for rounded chainrings. In my case was slowing me down, i was not able to keep high cadence with it, even in races with the changes in the pacing it sucked big time because biopace main characteristic is not help you to change pace making in a snap, by the oposite, was designed for a natural and slow pace keeping maybe 85 rpms tops, in races u can go over 110 with 53x15. I don't remember seeing those chainrings in any dura ace group back in the day, 600 and 105 had them in their groups.

Probably the new designs allow to change (accelerate) and keep that cadence at will, like rounded chain rings do.

Cheers.

[Birddog]

There really is quite a difference between Biopace and modern "out of round" chainrings.
http://www.rotorbikeusa.com/support.html

[peanutgallery]

bunk

they claim a 10% increase in power and a 12% decrease in lactic acid. sounds too good to be true, Millar would be a mere mouthy Cat 2 without them:)

If that data was real every pro would have been using them. What is the performance increase that could be attributed to blood doping? The pros are going crazy for that. I think that they are junk and a mechanic's nightmare. probably only effective in a really peculiar circumstance. better get a good 3rd eye/chain watcher, a crossing guard and tons of chain lube as it makes your drivetrain noisy and the f/d impossible to adjust. if you buy some you might as well get a power crank to go with them

Just my opinion but I think it is all BS

[ultraman6970]

We did not have anything back in the day, so do you think old timers care about all that paraphernalia? :D

After all w/o legs there is nothing you can do anyways.

[Mark McM]

did you ever look at the research that went into biopace? serious research of the same nature went into it so i dont really see how one can be more valid than the other (at least as a concept).

Shimano did do a lot of research, and their Biopace was the correct answer to the questions being address by their researched. But the questions being addressed aren't necessarily the same questions that Rotor or Ossymmetric asked.

Shimano was looking for a chainring that would be easier on the muscles for the largest portion of their customer base - recreational cyclists who typically ride at about 60 rpm. They weren't really trying to improve racing performance. For that goal, a different chainring shape might be beter suited.

So, depending on their goals, I think it is very possible for two companies to develop two different chainring shapes, that each are optimized for two different parameters.

But even here, there's probably a lot of room for personal differences in chainring shape selection.

[toaster]

There's no way rings can help with power over course of TT effort. Some research showed that in an anaerobic effort of 10 seconds or less these elliptical rings may show tiny gain.

[Fixed]

i was still doing triathlon when biopace came out a lot of guys said it hurt their knees as i remember .
cheers

[bigreen505]

One of the biggest differences of of the rotors is different positions so you can tweak them to what works for you. Another difference is 20 years of additional info. I have never used the Rotor rings, but am saving my pennies for a set. I had Biopace on a commuter bike in college and didn't think they were all bad.

[RPS]

Isn’t the main technical difference of any significant magnitude between the two concepts being discussed more about orientation than ring shape? I get that there are minor differences in shape between them but that seems minor compared to the overall philosophy of when to increase leverage at the expense of reducing it. Minor changes away from an ellipse or oval may fine tune the concept in the eyes of the makers, but the real substance is in altering leverage as a function of pedal position; and there they do it in opposite directions.

Since both argue benefits and have data to back up their claims, how wrong can someone go with straddling the difference and using a round ring?

[RPS]

Shimano did do a lot of research, and their Biopace was the correct answer to the questions being address by their researched. But the questions being addressed aren't necessarily the same questions that Rotor or Ossymmetric asked.

Shimano was looking for a chainring that would be easier on the muscles for the largest portion of their customer base - recreational cyclists who typically ride at about 60 rpm. They weren't really trying to improve racing performance. For that goal, a different chainring shape might be beter suited.

So, depending on their goals, I think it is very possible for two companies to develop two different chainring shapes, that each are optimized for two different parameters.

But even here, there's probably a lot of room for personal differences in chainring shape selection.
If so, could we use the same logic and consider that if one is possibly better for beginners and the opposite better for elite riders, then “maybe” round chainrings which split the difference may be better for most of us “typical” riders?

[RPS]

P.S. – One other difference I haven’t seen discussed is that non-round rings increase the minimum size (tooth count) of the small ring that can be used on a given crank spider. For those wanting the lowest possible gearing this may be another factor to consider.

[93legendti]

I recall Bobby Julich used them in the last 2 years of his career and won a lot of races

[peanutgallery]

I think the reason Julich was successful with them is because all of the goofy movements and noises in his drivetrain induced a mind-numbing hypnosis and seizures

[wallymann]

did you ever look at the research that went into biopace?

the new non-round rings are different to biopace. roughly 90-degrees different. IIRC biopace put the "big lever" at the weak points of the pedalstroke, whereas the new stuff put it at the strong points.

[bobswire]

Kinda like deciding which movie to see because of some Movie Critics opinion.
Unless you try them yourself all the data and opinions don't mean a thing.
I would love to try the Ossy's but at $300 a set it's too expensive of an experiment for me.

[RPS]

I recall Bobby Julich used them in the last 2 years of his career and won a lot of races
Lance won 7 tours riding Shimano, so why aren’t we all riding Shimano? Or Trek for that matter? :)

IMHO success data may seem statistically pertinent but may be completely irrelevant from an objective standpoint. Obviously if it sells more product it’s not irrelevant at all to the manufacturer or those who want to buy it.

[peanutgallery]

According to the Ossymetric website, Shimano rings don't increase power by 10% or hypnotize your opponents with motion and white noise


Lance won 7 tours riding Shimano, so why aren’t we all riding Shimano? Or Trek for that matter? :)

IMHO success data may seem statistically pertinent but may be completely irrelevant from an objective standpoint. Obviously if it sells more product it’s not irrelevant at all to the manufacturer or those who want to buy it.

[RPS]

The thing that puzzles me about the different ring claims is that pedals – and therefore feet -- still follow a perfect circle. Also, since no bike can change speed significantly 180 or so times per second, it therefore means that non-round rings mostly change pedal speed during the pedal stroke (not that there is anything wrong with that, but what's particularly right about it?). And as I questioned in a different thread not long ago, if a rider’s average cadence is 90 RPM and the feet vary continuously the equivalent of somewhere between 80 and 100 RPM, how can it lead to such great improvement when research has shown that our pedaling efficiency isn’t that limited as a function of cadence?

I’m not against the rings, but just can’t grasp the concept’s claim enough to even want to try them.