[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?

I tried them, did not like them, went back to round.

As the science shows there is no conclusive evidence of benefit. The difference only comes noticeable at much higher ovality than we have on bikes. The Osymetric Froome runs are the most extreme, but aren't going to work on a MTB, and on road cause major shifting issues.

There may be perceived benefits to knee health or perceived effort. That is highly personal, and you need to decide if you feel any benefit.

Since SRAM seems to be accused of being a marketing company a lot, you don't think if there was any scientific proof of benefit that they would not offer oval rings?

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

https://letmegooglethat.com/?q=phd+study+on+bicycle+chainring+ovality

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.

This is something I've worried about previously. Two things:
1) On a FS bike, chain growth occurs all the time, over compression but also with any bob.
2) All the clutch mechs I've used (both SRAM and Shimano over a number of years) have a small degree of 'float'. What I mean is that the end of the cage can move a small amount (5mm?) before the clutch fully engages. This completely absorbs any chain growth from the oval (which is small, but visible), Initially I thought this was just slop in the mechanism but I wonder if this is actually a feature that's engineered in because of (1).

TLDR: it's a non-issue IMHO.

Since SRAM seems to be accused of being a marketing company a lot, you don’t think if there was any scientific proof of benefit that they would not offer oval rings?

Can you rephrase that more clearly?

I have a technical question, can you run a chain guide with an oval ring? I'd have thought there's enough space but checking in case I've missed something fundamental with this...

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

I have noticed the same on very technical or steep climbs. where cadence is low. or if I am out of the saddle. The oval ring helps getting over the top of the stroke and seems a lot smoother than it did with a round ring.

I just think they are one of those things that works great for some peoples pedalling style and bike setup and not for others. That does not make them snake oil.

@twistedpencil yes, I had one of those wee One-Up chain retention device on mine (when I had an oval-ring fitted) there was plenty of room

It's easy to dismiss "Placebo" but it's a strong effect. I read of a trail where patients in a study were told the pills they were taking were just sugar pills, and would not help...Lots still reported a benefit/improvement. Even when people are told it's a placebo, the placebo effect works. If you think oval chainrings are helping, they probably are.

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.

This.

I have a oval on one bike and round rings on others. I can't really tell the difference. But ive spent years riding road and mtb clipped in, so i tend to "spin". My mate has a more "push" pedal stroke and he borrowed my bike with an oval on it once and loved it. Put them on his bikes too and claims they really help him smooth out his pedaling.

Interesting comments here...
I get the idea that suggests an oval ring will make you bob on a FS bike... but TBH, you bob on an FS bike anyway!!

I've an oval rind fitted onmy stumpjumper - I love it.. t feels smoother (to me) than a round ring..

I've an oval ring fitted to my rigid SS (my race/disctance bike) - I love it even more...again, it feels like it smoothes out peddaling, and makes the bike feel like it 'spins up' quicker..

Is this all in my mind..? Maybe..but at £50 a pop, and lasting several years at least, it's a pretty cheap drug...

DrP

https://letmegooglethat.com/?q=phd+study+on+bicycle+chainring+ovality/blockquote >

And yet, absolutely nothing on suspension design, chain growth, clutch mechs, bob or anti-squat which is what most of the discussion has been about here.

 

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.

I can't work out whether this concept is a red herring when it comes to mtbing. Apart from the dull bits where I don't give a monkey's arse about what my pedal cadence is like, for the rest of the interesting bits, the concept of pedalling in perfect circles off road is a complete fantasy.

I've got my first ever oval ring to try out going on my new bike so I will report back in a couple of weeks.

nickc
Full Member

It’s easy to dismiss “Placebo” but it’s a strong effect.

In these days of incremental upgrades etc it's probably one of the biggest effects there is tbh. If your bike feels good you tend to ride it faster and better. Like, when Steve Peat won the worlds, they literally took the bearing seals out of every bearing, degreased them, and oiled them. Did that make a difference you could measure? Probably not. Did sitting on the start line on a bike that you know has been prepped and honed to a completely ludicrous degree help? Peaty says yes.

Most purely technical discussions fail to acnowledge that the whole bike is run by a computer made of meat that hasn't had a software update since it used to be fitted in a monkey. It's why I like lighter bikes- I'm pretty comfortable that I can't prove a real performance benefit, but i like how it feels and that makes me want to ride further and faster. You could probably write OVAL CHAINRING on a round one and some people would find it feels better, and the point isn't that it's still round, the point is that the feeling is still real. Some people like suspension settings that are basically "wrong". Top end professionals have lost races because they couldn't find their lucky pants. You can't measure any of that on a dyno though.

I mentioned up the page that I do think there's a difference, though I wouldn't want to quantify it. But I think you've got to be comfortable with the fact that you can have a non-performance difference that leads to a performance improvement, if you've ever met a human.

Shred
Full Member

I tried them, did not like them, went back to round.

As the science shows there is no conclusive evidence of benefit. The difference only comes noticeable at much higher ovality than we have on bikes.

OK so, this is an interesting comment. Because you say the difference is too small to be noticable at the level of ovality you had; but you also say you didn't like it. What part of the unnoticable difference didn't you like?

That's a genuine question btw, not trying to be snarky. It's pretty common- quite a few posts in this thread amount to "the difference is too small to matter, but also it's bad".

I have shit knees

... so I bought an oval chainring for my road bike - but only the outer one as that's what was on offer

Now that is weird. Dropping from the oval to the round inner ring is VERY noticeable - feels like something is damping the rotation (which it sort of is, of course). There's no way that only I could feel that, it's very marked.

Doesn't make one or the other better or worse but they are definitely different

I thought I would try one a couple of years ago. I'm old enough to have remember Biopace back in the day and realise there is a 90 degree difference and this is trying to achieve the opposite effect.
(more leverage where there's more power, lower effective gear where there is less power

New chain ring needed changing anyway and I was oval curious to see if it helped me on climbs (see above about being old enough to remember Biopace).

Always been on flat pedals, never clipped in and I don't have a Strava account so I am not looking for PB's or incremental gains over long rides or whatever.

I ride a full sus, 2015 TR Scout so only 125mm and HL. I never use pro pedal or lock out.

I like it. I do perceive a small advantage on steep technical sections, traction is good and makes them more fun to me. I don't perceive any disadvantage anywhere else. Might be a placebo effect, I don't know. I might go back to round next time to see if I can see a difference the other way.

On the placebo effect. My 8 year old boy is convinced it gives me some kind of super power and totally sees it as an unfair advantage. I tell him it means that I don't need to by an Easy bike for a few more years yet.

I'm as much a roadie as an mtber, I can spin pretty well. The oval ring on my SS feels good, I expect because of how it works at lower cadences. But I'm not thinking it is any mor efficient.

Top end professionals have lost races because they couldn’t find their lucky pants

No: they just think they have.

Well it arrived folks and it has been fitted

By the way it has been fitted to my new Sonder Camino

I think the reason many shout 'placebo' is that when you initially go from round to oval the perceived difference is usually small, or even nonexistent. That's because your muscles and brain have been on round all your life, so that's how you pedal. At this stage many say 'snakeoil' and go back to round.

But if you give ovals a bit of time - I'd say at least 250 miles - and give your your muscles time to adapt to the different stresses, when you go BACK to the round it feels REALLY different. This is basically what scadeypants is saying with his round/oval 2-ring setup.

So, once you adapt to oval, then go back to round (on a mate's bike, say) then it just feels rubbish, frankly, as you blow through the power phase far too quickly. It's not subtle either. This is also more pronounced on hardtail/rigid/road bikes IME.

I have round on one bike and oval on the other two at the moment, I can absolutely tell the difference but neither feels weird any more - in the way that the first ride on an oval ring did.

My gut feeling is that any increased efficiency claims for oval rings are snakeoil, but the "crawling up steep climbs" benefit is real and very noticeable.

I think any effect of an oval ring is masked by using gears, you select a gear to get a decent pedal stroke. Used one in a 1x and didn't really feel any different, though I was used to one on my SS by then.
Fit one to a SS and they do feel beneficial to me, or as clearly as I think feel and bad science testing can indicate. At a low rpm but not fully straining or stall point sort of climbing effort they seem to help keep momentum or rhythm despite being a couple of teeth larger. The benefit when spinning along at high cadence low torque is simply that my gear is 2 teeth higher than the round ring that it replaces.

I get the idea that suggests an oval ring will make you bob on a FS bike… but TBH, you bob on an FS bike anyway!!

That's it, I think to say whether it's a benefit on a given FS bike you'd need a complex model of both rider pedalling style and the bike's linkage design, shock set up, etc. So back to feel and bad science for most of us then.

So back to feel and bad science for most of us then.

You say that like it's a bad thing.

^ ha, no, it's just a thing. Isn't bad science just testing for opinions vs proper science testing for facts?

But if you give ovals a bit of time – I’d say at least 250 miles – and give your your muscles time to adapt to the different stresses, when you go BACK to the round it feels REALLY different.

I have done probably thousands of miles on oval and now back on round. Can't say I can feel a huge difference. That's not to say there isn't a perceptible difference, just not for everyone.

I'd like to A-B test oval vs round on the same bike (like scaredypants has done) before drawing any firm conclusions though.

the whole bike is run by a computer made of meat that hasn’t had a software update since it used to be fitted in a monkey.

This is brilliant 😀

^ ha, no, it’s just a thing. Isn’t bad science just testing for opinions vs proper science testing for facts?

Bad science is testing for opinions in a non-scientific way. Opinions *are* facts, and are important and worth measuring. But of course, what the measuring them will tell you is what the opinions are, not whether they are true.

The April fools are early this year

or 3 years late...

DrP