[Closed] To oval or not to oval

I love mine.

https://flic.kr/p/VEepzC

Best way to ruin an a full suspension bike if you ask me... Of negligible benefit (certainly none that can be measured) on a rigid back end, but definitely counterproductive on a full suspension bike...

If they were even remotely as good as they claim they are, then every new bike would be fitted with one (go to a bike shop, see how many manufacturers fit them as stock!)... They are the cycling worlds equivalent of Golf's "This Driver drives 20yds further than your existing driver" claims...

Oh, and they feel horrendous if you have spent any amount of time perfecting a smooth pedalling technique.

But don't let my negativity get in the way of the marketing hype! 😉

As a sucker is soon parted with his money, then that’s me.

but definitely counterproductive on a full suspension bike…

What makes you say that?

I’ve not read anything saying so but I’m happy to be proved wrong..

If humans produced an even power stroke then yes, round rings would be optimal. But they don't.

As for the 'new bikes don't have them' argument then that is flawed too, as drivetrains are dominated by Shimano and Sram so you get what they engineer. If new bikes were perfect then we'd never tweak the specs, and stick with the showroom bike. I've certainly never done that and I doubt most on here have.

As for 'feeling bad', well that is a subjective argument so anyone can have their opinion on that one.

As for 'counter-productive'.. well that would depend on what you mean. Do you mean suspension performance?

I'm another oval believer, and I don't play golf.

I've liked the ones I've used over the years but I don't really miss them when I'm on a bike with a round ring. I do think you notice the effect more when singlespeeding.

For me:

Orange 5 tick

Gravel bike tick

Oval tick

Gaggia Classic tick

But don’t let my negativity get in the way...

edited: you can do your own googling for the much more positive research, I promised myself to give up arguing on here.

Enjoy your Abs Black OP, after about 5 pedal strokes you won't notice the difference, but it will be helping.

Brilliant kit

I can see why they wouldn’t work on a full susser.

Also interesting that YouTube vid with Chris Froome where he was told not too use an oval ring in his rehab but will when he starts racing again

I do a fair bit of really steep shortish climbs, for me, that's when they come into their own. I've used them for about 4/5 years. They annoy me on fast singletrack where the powers on/off through the drive chain, it seems to clunk a bit as the power goes back on. I've gone round for my next chainring but not fitted it yet. I don't really notice any difference as i swap between bikes with round / oval rings.

I always wonder about the idea of "pedaling technique", do people actually think about this? I have been riding bikes since before I can remember and never felt the need to improve my technique, my fitness on the other hand has often required improvement....

Fwiw, I have an oval ring and some round rings. I've got so used to the oval ring that I can't tell when I switch bikes any more. I probably can't tell the difference with the oval ring but it does look pretty.

I have the same AB oval, pretty aren't they?😁 Ovals are great.

They haven't cured my knee but they help a lot.👍

I've recently fitted one to the full sus and had a few good rides. My main apprehension was about the look of it. It just looks wrong. But I can live with that. Can't say i can really notice the difference apart from the on/off feeling as described above. Maybe I'll notice when switching between that and the hardtail.

I have a theory that it stops my feet pinging off the top of pedals when I'm climbing steep stuff on flats. But the rest of the time I don't think it makes much difference and as mboy says perhaps it is detrimental, particularly when suspension these days are optimised for a particular chainring size.

I always wonder about the idea of “pedaling technique”, do people actually think about this?

I think it's a roadie thing. On a road bike you have a lot of time just cruising, admiring your silhouette and can assess pedalling style. Some people definitely do it better than others. On an MTB I can't say I ever give it much thought.

Thanks for all the feed back either way.

For me it’s worth a try if it gets me out further

There are some fantastic riders on here who a few years I had the privilege of meeting up with and some who spent a lot of time getting me up the trail, helped me select my first two decent bikes.

At 57 and recovering from a train crash of a medical condition i want to ride longer, meet with folks on here and not be the slow fat bloke at the back.

The weight has dropped 5 stone and the riding becoming a pleasure.

My goal is to get up the Hepstonstall Road all the way to the Pack Horse Inn without a stop, then I have cracked it.

If an oval helps then why not

Tried one. It gave me knee pain. Gave it away and stuck to round since.

An oval AB PVD oil slick fan here - have it on my Trek Top Fuel and I can't say that it has done anything negative to the suspension action, or the way it rides.

If anything, its made it an even better climber. No dodgy knees either.

Shame about everything else about my body creaking away, but that's not the fault of the oval ring.

The issue with suspension bikes is oval chainrings constantly change the anti squat, so in theory could make the suspension bob. Also where the rider puts the most power in is actually the softest point for ovals/anti squat, which is sub optimal. One of the supposed benefits of oval rings is traction, suspension bikes already help with that.

After many thousands of miles using oval chainrings I went clean off them. Once my leg muscles got used to the way they pedal the benefit was lost, and after a while it actually started to feel harder, not easier. Noticed this most when I went back to round and realised how much leg strength had been lost. I believe oval chainrings, among other things, partly caused knee problems I had a few years ago. It’s something to do with rhythmic changes in resistance and cadence from the oval ring causing a kind of successive impact or strain on knees when pedalling. Others have said similar.

admiring your silhouette

I'm not so keen on doing that, it tends to look like a partial eclipse.

I like em

Well this is unexpectedly contentious.

Personally I appreciate how they make steep climbing just a touch easier, but I prefer the feel of a round ring for pedaling generally.

Good for ekeing out a bit more at the lower end if you don't have a super-wide 12 speed cassette.

Basically, I'm not that fussed either way.

Looks like it's going on a gravel bike. What you will notice is that it smooths out the power, improving traction - you know all those times where you're inadequate tyre tread slips under power. Or maybe it won't work for you.

Oh, and they feel horrendous if you have spent any amount of time perfecting a smooth pedalling technique.

Why do you have to practice/perfect your round pedal stroke if that's how your body wants to do it naturally? I agree with you on the full sun thing though, but I guess it depends on the bike.

Hardtail oval thumbs up from me. I found Covid recovery easier with one.

Are all ovals the same, or are some more ovally than others? Is there a perfect ovally ratio?

I was running an oval for a few years on the mountain bike. I even put one on my commuter.
A year or so back I got a new MTB with a round ring. My intention was to run an oval on the new bike but after riding it with the round ring I didn't notice any difference so never went back to oval.
Still have an oval on the commuter and switching between the 2 bikes don't notice any difference.

This point about 'sus bikes are optimised for a certain chainring so oval rings are no good on a sus bike' -

Most linkage bikes have variable pivot points through the travel, around the sag/pedal position as well as through the full range.
Single pivots bob more when chain tension varies.
All sus bikes benefit from a smoother pedalling style.

So perhaps an oval ring that moves up and down by +/- 2 teeth height is as likely to be beneficial as detrimental on a linkage bike. If it smooths out your pedalling for more even chain tension it would be beneficial there.
But whether the oval helps you pedal more smoothly for even chain tension or simply gets a benefit from a choppy pedalling style I'm not sure. I like the one I have on a rigid SS though that tells me nothing about use on sus bikes .. looking at the areas/teeth that get the most wear it's hard to imagine I get more even chain tension - more likely more use from the 2-5pm stroke and low cadence, higher torque pedalling.

Marmite then.

mboy has it. "Belief" was mentioned above - sums it up for me, where's the evidence?

The issue with suspension bikes is oval chainrings constantly change the anti squat, so in theory could make the suspension bob. Also where the rider puts the most power in is actually the softest point for ovals/anti squat, which is sub optimal. One of the supposed benefits of oval rings is traction, suspension bikes already help with that.

Somebody who actually understands the Science, and hasn't just bought into the religious cult! 👍🏻

After many thousands of miles using oval chainrings I went clean off them. Once my leg muscles got used to the way they pedal the benefit was lost, and after a while it actually started to feel harder, not easier. Noticed this most when I went back to round and realised how much leg strength had been lost. I believe oval chainrings, among other things, partly caused knee problems I had a few years ago. It’s something to do with rhythmic changes in resistance and cadence from the oval ring causing a kind of successive impact or strain on knees when pedalling. Others have said similar.

There are no measurable benefits of Oval chainrings... When fitted, the rider will experience a "difference" that sometimes they will assume to be an improvement... At best, there may be a placebo experienced, at worst they are detrimental to performance. They prey on people with choppy, low cadence pedalling styles, especially those on flat pedals. Those who have spent any amoount of time perfecting a smooth pedalling technique clipped in and on round chainrings, will find they are totally counterintuitive.

Are all ovals the same, or are some more ovally than others?

Some are indeed more oval than others... There's some pretty wild profiles, and some much milder that I have seen.

Is there a perfect ovally ratio?

Yes... ZERO... A Round Chainring in other words! 🤷🏻‍♂️

Well this is unexpectedly contentious.

Not really... Oval rings have more followers than religious cults, mostly similarly blind to the science too! But as with religious cults, and mudeverywhere a few posts up, users have to find out for themselves that their emperors new clothes aren't all they're actually cracked up to be, as they won't listen to an unbelieving heretic like me!

Marmite then.

In my experience, people can generally discuss their love or hate of Marmite over a pint, and then put their differences behind them... Oval chainrings are a little more "Gaza Strip" or possibly even "US Gun control" by comparison... 😉

There was me thanking this thread that I've got an oval ring sat in my toolbox and that my current chainring is knackered. I thought I'd save some cash by sticking the oval ring but I'm not sure I want to venture over Gazza's strip...

The issue with suspension bikes is oval chainrings constantly change the anti squat,

Chain tension and chain angle affect anti squat, chain tension variance through the pedal stroke isn't necessarily greater with an oval ring and though the angle change is there, it's also there in a different way but greater extent when you change a few gears. I can't do the maths to balance it all up but I'm not convinced it's simply a bad thing.
My guess is some FS designs would be affected by it more than others, some worse off, some better.

I can't honestly feel any difference most of the time, but then that's not really how pedalling works.

But... On the fatbike, there is a difference I can feel. It's not "this is easier" or "this is like a lower gear" or any of that. Again, that's not really how pedalling works, if it was easier I'd just change gears or go faster or just be lazier and not think any more of it. It's that it blobs along more with round than it does with oval. And it's the sort of thing that's very repeatable, since it happens most noticably when you're just sitting and spinning along, and I've done an awful lot of that on that bike. Why does that matter? Well, every bit of movement comes ultimately from me and every big of movement going blob blob blob a little bit up and down is a bit of movement that isn't going forwards, a little bit of energy wasted. Is it the ring that's doing it or is it the legs responding in some way to the ring? Don't know either.

Of course, if I was really worried about the energy loss of that blob blob blob I'd stop riding the stupid thing and ride my Solaris instead.

Obviously no anti-squat or suspension kinematics to worry about on that bike, but on that subject, if that's something you're thinking about ask yourself first why you're assuming that any change that it may effect is for the worse. Most people pick chainring size for ratios not for antisquat so the odds that you happen to have a "perfect" chainring for that are probably not brilliant, whether it's round or oval. And a suspension design that's so specific that it can be ruined by the owner's chainring choice, probably isn't very good.

My guess is some FS designs would be affected by it more than others, some worse off, some betterless worse off.

FTFY 😉

Chain tension and chain angle affect anti squat, chain tension variance through the pedal stroke isn’t necessarily greater with an oval ring and though the angle change is there, it’s also there in a different way but greater extent when you change a few gears. I can’t do the maths to balance it all up but I’m not convinced it’s simply a bad thing.

Agreed, apart from the last few words of the last sentence... You will get more change in Anti-squat on the same bike changing from a 30T round to a 34T round ring than you would experience with an oval ring, however... The Oval ring is experiencing constant changes in Anti-squat all the time you are turning the pedals, every 360deg crank rotation it has experienced two high points and two low points, which for a typical 90rpm cadence will have you bouncing down the road/trail at 180bpm... An oval chainring is causing constant micro-squats and extensions of the suspension, unless you learn to pedal around its inherent ovality on purpose.

I used then for 2 to 3 years, then when I bought my slash I put one on and it felt awful, like it was sapping my power, went back to round on that bike and it was fine. I have a fairly slow cadence 70-75* and that is possibly better suited to oval rings. I still have an oval on my hardtail and will probably fit one again when it wears out. Not sure if any differences experienced are real or just in my head though.

Dylan Johnson delves into some of the scientific research, and it's inconclusive.

*there is no conclusive science to support faster cadences either.

Placebo or not, I've been on Oval rings on the hardtail and FS bikes over the last 3 years and won't go back to round rings. I've found when climbing I can pusher a harder gear than I would normally and back to back, traction seems marginally better on steeper, looser ground too. The Spur came with a 32T round ring and I swapped to a 32T oval, I didn't notice an increase in bob, so if the anti-squat changed it was minor enough for me not to notice. Going from a 38/24 on my old Mojo HD back in the day to a single 34T, I did notice though, comparing the 38t to the 34T, 38T felt noticeably plusher, presumably due to drop the in anti-squat. At the end of the day, I think they'll suit some riders and not others, I've noticed no difference perceived downsides and a marginal gain in some areas so I'll stick with them!

The issue with suspension bikes is oval chainrings constantly change the anti squat, so in theory could make the suspension bob. Also where the rider puts the most power in is actually the softest point for ovals/anti squat, which is sub optimal. One of the supposed benefits of oval rings is traction, suspension bikes already help with that.

Somebody who actually understands the Science, and hasn’t just bought into the religious cult!

Well I understand some of the engineering and disagree (I think it is better called engineering than science?). The change in anti-squat will be minimal, in the middle of the cassette less than the change you would get by changing one gear. This change will be dwarfed by the change in most cyclists' pedal torque over their pedal stroke. Smoothing that out (which oval pedals are alleged to do) is essentially the same thing as evening out chain tension during the pedal stroke, and chain tension is what mechanically causes bob/squat* as it is how drive is transferred**. To model the overall effect of an oval ring on squat/bob would be a complex exercise, probably beyond me though I don't intend to try.

* Different but related things.

** With no chain, you can't have squat, but you would get bob if for some reason you decided to pedal anyway.

The Oval ring is experiencing constant changes in Anti-squat all the time you are turning the pedals, every 360deg crank rotation it has experienced two high points and two low points, which for a typical 90rpm cadence will have you bouncing down the road/trail at 180bpm… An oval chainring is causing constant micro-squats and extensions of the suspension, unless you learn to pedal around its inherent ovality on purpose.

One of us doesn't understand this properly. I think it's you, but I'm not sure. Oval rings cause a change in anti-squat, I accept this, but it's a small change (5%?). So you're looking at a small change in anti-squat over time, you're talking about the derivative of it. I.e. d(squat)/dt. Change in chain tension (which is the relevant thing here) is itself a further derivative of the change in anti-squat. Nevertheless, I suppose if the pedal torque was constant then this change in anti-squat could set up an oscillation than would potentially cause a bob in itself.

But of course the force applied to the chain is not constant throughout the pedal cycle, which is why bob is a thing. In fact, it's this thing that oval rings are actively trying to combat. Variance in chain tension throughout the pedal cycle is huge (at least 50% in the only decent study I found in a very brief search https://core.ac.uk/download/pdf/41530915.pdf). So you're comparing a 50% change in the force over time with a 5% (my estimate) change in anti-squat.

If the ovality has even the slightest effect it's claiming to have (smooth out the pedal force variance) then that would easily overcome the tiny effect on anti-squat.

I don't know. Someone clever needs to do a simulation.

At best, there may be a placebo experienced, at worst they are detrimental to performance.

Like someone else said:

where’s the evidence?

I'm mostly in favour of acting conservatively unless a change can be demonstrably beneficial. So whilst I think there's a good possibility that oval rings are snake oil, you're being very antagonistic without evidence to support your claims - other than some back-of-napkin ideas about suspension kinematics (which I think are incorrect, due to my own back-of-napkin calculations).

EDIT: I was 31 seconds too slow. What he said ^^

Some good comments there.

I prefer not to worry my pretty little head about the "science", but I ride a lot and trust my own feel for whether they help or not.

Just to introduce another variable - my feeling is they are more useful on my single-pivot bikes than my four bar. And I'll go back to round on that when the current ring wears out.

One thing I've wondered about is whether Oval Rings lead to premature wear of mech clutches - since the 'chain length' alters on every revolution of the pedals.

No evidence this is a real problem and my clutch failures wouldn't have been avoided by doing even the most basic maintenance. But whenever I've actually ended up maintaining a mech it's ended up in the bin*.

(*as in, now I've looked at it properly the jockey wheels are shot too, and it's quite evidently bent....)

Better give my own view then...

Being old and weak of leg, I am always in too big a gear on steep climbs. An oval ring feels like it helps me get the pedal over the top. So it extends the range, as it were, at the slow end. I haven't noticed any effect on the top gear, but I suppose there could be a balancing reduction at the top end. You would think round wold be better for high cadences - you don't see ovals on track bikes, for example (do you?) But spinning like crazy isn't my thing these days. I plod, and an oval ring definitely helps with plodding.

So I can imagine that research focussed on racing and pedalling at optimal cadence is inconclusive.

But a complicating factor with tests of this (crank length is the same possibly) is that it may take time to adjust pedalling style and cadence so it is optimised for an oval ring etc. So you don't want to compare like-with-like, back-to-back etc., you would need to fine-tune a rider and bike to get the most out of oval, and then with round, and compare.

@Superficial lol... this of course just reinforces the collective oval ring delusion.

I bought an oval chainring by mistake. I fitted it anyway.

Can't say I really noticed any difference. I hadn't ridden that bike long enough with a round ring to make any useful comparison. My other full sus has a round ring but a different suspension design so again its not really possible to compare. But it doesn't feel weird or different when I ride it I just get on and pedal. I'm on flats on both bikes.

And obviously there are roughly 47 ring and crank "standards" so I can't easily swap rings between bikes to do a proper comparison.

Needs more data. Does anyone have a tame Phd student that can do a proper study on it?