Today’s question is from a cyclist with knee problems. She is wondering about the Q Rings from Rotor (a specific type of oval chainring) and if they can help with knee problems.

As with any type of pain treatment, you want to do your research.

Should I Switch to Oval Chainrings?

Howdy Coach,

Do q rings help with osteoarthritis in the knees? I have compact Specialized Ruby. Should I change?

Ruby Warrior

rotor q rings on cranks

Hi Ruby,

Interesting question! I’ve had knee problems myself but never considered anything like Q Rings to alleviate my pain.

First, let’s be clear – I’m no doctor nor do I have personal experience using Q Rings. And since they’re your knees and it’s your money (about $265 of it), I’ll let you make the decisions on new products!

That said, I do have some thoughts on these rings and the decision making process…

What are Rotor Q Rings?

Q Rings are ovalized chainrings, rather than the typical circular chainrings. The concept behind them is explained on, and I’ll share an excerpt here that’s specific to their compact rings:

By extending the time you spend in the power stroke (where 90% of all power is produced) and smoothly accelerating the legs through the critically weak “dead spots”. A 50T Q-Ring, around the upper dead-spot is equivalent to a 48T, but as the pedal goes down and more strength is applied, the equivalent chainring tooth size reaches 52T.

Each ring is like two rings in one. Basically, when your legs can produce the most power output, they’re pushing against the equivalent of a 52T chainring. When your legs are in a weaker position, they’re pushing against the equivalent of a 48T chainring.

Why were they invented?

The goal was to eliminate the dead spot of traditional cranks in order to generate more power output overall. By making it easier to push through the dead spot and harder at the spot where you have more power, you effectively produce more power without expending extra energy.

What about knee pain?

I’ve heard reports that these oval rings alleviate knee pain… as well as reports that they cause new knee pain!

Think about it this way. If your knee pain stems from having a hard time pushing through that dead spot, it stands to reason these rings could alleviate some of that pain (while still allowing you to use the same gearing). Yet, the extra effort required during the tougher section of pedaling could negate all that. It could also present its own problems and perhaps new knee pain!

It’s tough to say.

What I know is, all knee pain is different, so I’m not surprised to see the conflicting findings in rider reports and discussion forums.

There is one study on knee health (linked from Rotor’s own website) that concludes with “… the Rotor propulsion system effectively preserves knee health,” but it’s not specific to existing knee problems. It did mention comfort during the pedal stroke, though, which I would think is a good sign for your knees.

It seems most other studies looked at performance, like this one which showed no improvement in performance over a 10km time trial.

I don’t think the studies will really give you any actionable advice. But if you want to study the research, this site has collected it.

What does Rotor say?

In a PDF document provided by Rotor, I found a few reasons why Shimano BioPace and Osymetric rings (i.e. Rotor’s competitors) can supposedly increase knee pain, but there was no mention of what Q Rings can do for knee pain (for better or worse).

I questioned Rotor about this, and I received a very intriguing response from Christie O’Hara, who has been working on research studies with Q-Rings for the past 3 years! I copy and pasted this part so I didn’t screw it up:

Non-circular chain rings (primarily designed to improve the performance of professional cyclists) can provide a solution for those that suffer from osteoarthritis (it is important to limit the loading at their joints during exercise). When the pedal is in the higher dead point and the load at the knee is maximal, the chain radius is the shortest (thereby reducing stress), then, while the pedal is getting closer to the horizontal, the load at the knee gets lower and the radius reaches its maximum, then it decreases to the minimum value in the lower dead point.

I think what it boils down to is that this type of chainring will reduce the load on your knees. And since it does this on every single pedal stroke, it could make a substantial difference over the course of a ride.

Now, the really interesting part… is the new study being designed right now to take place in the fall! It sounds like they’re actually going to study knee issues as opposed to performance, so this will be right up your alley!

What’s the source of your knee pain?

The biggest worry for me, at least for now (since the study won’t be complete for a while), is whether or not the load on the joints is the root cause of your problems.

For my knees personally, I believe the problem comes more from the pedaling motion than from the load on my joints.

My theory is, at the moment of impact, it doesn’t matter what the chainring’s overall shape is. It’s still the same type of resistance. Likewise, the pedaling motion is still the same and the force is still applied in the same manner. Your knees are still traveling in the same circle, as dictated by the crank arms.

That’s just me though. Since your knee issue is different from mine, the rings might be just the ticket. And don’t get me wrong – the more I think about the rings, the more I want to add them to my shopping list!

What would I do?

In the end, I believe it’s one of those things that’s completely individual. Same with supplements and knee surgery – it’s impossible to predict the outcome for a specific patient.

Perhaps you’ll be able to ride slightly faster without doing extra damage to your knees. So maybe that’s worth it. Perhaps you’ll enjoy the feel, and maybe that helps you enjoy the ride. Maybe you’ll be 100% pain-free. It’s a gamble.

So, first, make sure you read the articles I’ve linked throughout this one for some more insights and first-hand accounts from other riders.

Then if you want, try the rings – either the Q-Rings or the Osymetric rings – and hope for the best.

Show References

If any readers out there happen to have tried any type of oval, elliptical, or non-round chainrings, whether BioPace, Q-Rings, or Osymetric rings, please chime in with your experience in the comments!

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