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Ovalized Chain Rings

I can't give any kind of scientific report, but I did use the old Shimano Biopace rings on a ride across the United States back in 1988. I had no prior experience with them, except for riding the bike for the 2 months prior to the tour while training. Although I never felt any problem with the design, because I also never felt an advantage, I don't think I would ever consider their use again.

If I'm correct, Shimano's idea was that the lower effective gear while in the "power phase" of the spin cycle (somewhere around 2-4 o'clock), the speed of the pedalling motion would increase, and that momentum would now help carry you through the weaker "dead phase" of the spin cycle (around 4- 8 o'clock). I have no idea if there is any truth to this, and I said, I never felt any advantage to the design. IF they did help at all, it might have been while trying to maintain a momentum in my cadence while pedalling my loaded bike up the mountain climbs. But even that, I question.

Funny thing is, I believe earlier designs of oval chainrings were made with an opposite pattern. In those, it was believed that you should have the HIGHER effective gear while in the power phase, so that the power you now produced would carry you through the dead phase.

Oval chainrings, like cut-out saddle designs, have been going in and out of vogue for many decades. I remember seeing an old bike from the early 20th century that was on display in a bike museum in Murdo, South Dakota on my cross-country ride. It had an old Brooks-style saddle with a cut-out.

I would be curious to hear reports from other people on oval chainrings.
Mar 16, 2009
Michielveedeebee said:
do those have specific shape?


Jul 24, 2009
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cawright1375 said:
Is there anyone out there using ovalized chain rings? And if you are did you really notice a difference and did it take some getting used to?

From what I've read on the Intertubes, the deal seems to be that they help low-cadence grinding. If you spin at high rpm there doesn't seem to be a statistically-significant difference. But there is not much information regarding highly-trained cyclists (and studies involving non-elite cyclists are not very useful). The most promising test involved a handful of Spanish pros riding up a hill with and without Q-Rings. Power was nearly 1% greater w/Q-Rings, but cadence was fairly low (70s?).

I guess that when the Metrigear Vector power meter finally hits the market, we'll be able to see what different bike positions, chain-rings, cranks, cleat-positions, ... do to our individual pedal-force profiles. But currently, it seems that there is too much individual variation to make sweeping statements on any of these issues.
Mar 18, 2009
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marathon marke said:
And then there's the question, will oval/ellitiptical rings hinder tempo changes when you want to accelerate?

I've been using Rotor Q Rings for 7 years and have heard a lot of speculation about elliptical or non-round chain rings. Here's what I've experienced first-hand:

-I've never had a problem with tempo or cadence changes on Q rings, they accelerate the same as round rings. I can spin at 130 rpm or slog along at 50 rpm without my chain rings causing me any difficulty, ditto for jumping from tempo to attack speed or back down. If anything, I feel like they help get me up to speed quickly when I have to jump.

-No problems with spinning at a high cadence (100+ rpm). I don't know where the rumor that you can't spin with elliptical rings comes from, but I suspect it has more to do with individual riders having poor pedaling technique that they notice because they are trying new equipment and paying attention to their pedaling, not because the rings are making them pedal squares :p.

-When I race on the track I use round rings (although I just got a Rotor track ring to try out :)) and I also use round rings on my single speed MTB. There is no noticeable "weirdness" when switching between round and elliptical rings.

-The "learning curve" for me was one ride. Actually less than that, because by the time I got home i had completely forgotten that I had different chain rings on my bike. Equipment that "disappears" when you ride is a good thing, or at the very least not a bad thing.

-Where I notice the benefit of Q Rings most is while climbing or at high power output on the flat. It's hard to explain, but it actually feels smoother, like my power output is more even throughout the pedal stroke and I'm maintaining an even speed. It feels more fluid, for lack of a better adjective.

So there's my little diatribe :p. Seriously though, if anyone has any questions about using Q Rings (I have no experience with O Symmetric rings) I'll be happy to answer them.

[FYI/disclaimer: I don't work for nor am I sponsored by Rotor, I just like their products and want to help others get past the rumors and speculation.]
Mar 18, 2009
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Greyhound Velo said:

Thanks for the 'diatribe'!

I was actually going to open a thread on Q rings when I saw this one on oval rings.

I'm looking at a bike equipped with Q rings and had (and will likely have more) questions about them.

The shop guy said in his experience you either like them or hate them...he hasn't seen many sitting on the fence.

Another thing he mentioned was a new soreness in the legs for the first couple of weeks as your body adjust to them.

Any experience with that?
Feb 25, 2010
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krebs303 said:
oops teach me to read with out my glasses Q and O. look the same.

yes I knew O-rings were very radically ovalized :p
Saw a foto on CN of Sastre's bike with Q ring and it did not looked elliptical or anything so I thought I'd ask... Thanks anyway ;)
Mar 18, 2009
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I didn't have any physical issues with getting used to them, but that may depend on the rider. I tend to think the sore legs might be due to wanting to push harder on climbs to see if the new rings make a difference. Another case of unintentionally causing a problem due to trying harder or testing, rather than the new equipment causing it directly.
Jun 8, 2009
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I have ridden on Q-rings for 18 months now, and am pretty sure I will never ride round rings. My dealer, who is now a Rotor dealer, which he wasn't when I ordered the first set, explained the properties to me, which I will try to combine with my own experiences. Here goes:

1. The notion that you can't spin is wrong. I am a unusual rider in that I ride with quite high RPM's and sprint in a very big gear. And sprint is what I do very well. In both cases the rings is helping me. I use less effort when riding along, as the spin is better, more natural and round. And in the sprint they help me to push the big gear and start the sprint a bit earlier.

2. Your spin gets better/rounder because compared to round rings, your foot speed is nearly the same across a full revolution, whereas on round rings your foot is accelerating on your "power phase" and deaccelerating on the top and bottom. This is not very effective seen from a biomechanical point. So the Q-rings force you to spend longer time where you can apply power and get your foot quicker over the dead points.
So the net outcome is that there's longer time to fatigue. I can feel clearly that, as I'm better able to keep pushing on the top of the hills and is generally more fresh when I get to the sprint.

I have now put them on my MTB also, where they also provide better traction because your "peak" power is cut a bit and your power is distributed over a longer period. I'm told that they are very popular in cross, as they often need better grip/traction on the muddy and sandy courses they race on.

The negative parts is only that it can be a bit tricky to set up the FD. Especially on some Shimano FD's. But it can be done. On SRAM, Campy and Di2 it works perfectly.

I have never tried the Biopace rings, but I understand that they had 7 phases and generally worked almost opposite to the Q-rings. I think they were made for riding to the bakery? ;-)
May 8, 2009
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I use Q-Rings for the last 2 years, and they are fantastic. My pedalling is more fluid, and I feel the advantage specially while climbing seated on the saddle, using a lot of power up. In those moments of suffering one tend to "loose" the right pedalling form, focusing just in applying torque and power. I can keep better pedalling with the Q-rings in those circumstances.

It took me a while though to get used to them, about a month. I would recommend to start with them in the winter, with long but not hard rides, to avoid potential knee damage.
Speedneedle said:
I have never tried the Biopace rings, but I understand that they had 7 phases and generally worked almost opposite to the Q-rings. I think they were made for riding to the bakery? ;-)

I've got Biopace on my old steel bike. It works fine (but I spend most of my time in the big chainring, which is more round than the small chainring). The idea is that you increase the speed of your leg during the downstroke and use that momentum to get through the dead spot, at which point your leg is moving fairly slowly. This reduces the strain on your knees at this dangerous spot in the stroke, where your leg changes direction.

Q-rings do the opposite, giving you maximum power delivery during the downstroke and racing your leg through the dead spot. Which one is better (or just regular round chainrings) may depend on your technique, physiology, strength, etc.

More info:


PS. You can install Q-rings in the same way as Biopace (and vice versa), although the shape is somewhat different.
Michielveedeebee said:
How much do those Ovalized rings actually cost?

About 100 bucks for a chainring.

They also sell their own cranksets that include their chainrings for about 400 bucks.

Who knows? They might actually work. The idea that the chainring minimizes the top and bottom of the pedal stroke where you can't apply that much power, and lengthens the up and down strokes where you can apply power actually seems reasonable.