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Midway through last year i picked up a couple of oval chainrings - an absolute black and a rotor. I was attracted by the claims of enhanced traction and increased efficiency. I've done a several thousand miles on them on my two main bikes - and developed knee pain. I've never had knee pain before. I've taken them off the bikes now and replaced them with round ones (both of which are two teeth larger) on which i've ridden about 500 offroad miles. Knee pain gone. I might have got a bit fitter, but i think that's very marginal. Clearly, this is anecdotal but all i can say is that on the downstroke my knees felt like they weren't supported. This was particularly the case when i was tired and not pedalling too smoothly.
For me, not only could i not perceive any benefits, but i actually found them harmful.
on the downstroke my knees felt like they weren’t supported
May be a silly question, but were they on correctly? On the "downstroke" with an oval should be where the gearing is the tallest as that's where the leg is the most powerful. I have used ovals quite a bit in the past, and if anything they were a lot easier on my knees which are generally in a fairly sorry state after years and years of poor skiing decisions 🙂
Yeh the downstroke has maximum leverage so should provide more resistance/support to the foot. The only time I could really notice the oval ring was on rollers, when the pedalling felt lumpy. But the momentum/mass of the bike in the real world smooths this out.
Me too. Back to round and all is fine. And yes, properly fitted.
Tbh they were fine when mashing, but just didn't spin that well compared to round rings.
Same chainring sizes?
I think the benefits of oval rings relate to the slightly lower gear at the flat points. I know there was some chat about 'going up 2 teeth' if you go oval, which would just negate those benefits and result in tou pushing a slightly bigger gear on the downstroke.
All my knee problems relate to pushing too hard a gear, the smoother and faster I can spin the happier they are...
The rings were orientated correctly. I know the theory that the gear ought to be at its tallest on the downstroke, just wasn't feeling like that. The rotor was particularly bad for me - maybe because it is more ovalised.
Like yak said a round ring just feels more even - obviously i suppose - with the result that my pedalling is smoother and my knees are better.
Going from oval to round and going up in teeth seems odd. Provided you had the rings on the right way you have just increased the gearing at your dead spot by about 4 teeth which would normally be the trigger for knee pain not the reduction of it.
Only had oval on road bikes and liked them, mainly because they reduced my knee pain! We are all different I guess. You absolutely sure you had them on correctly - very easy to mess it up and give yourself a DIY biopace.
I was attracted by the claims of enhanced traction
presuming you mean with the ground, how does a chainring shape produce more tyre grip?
@rocketdog - the theory is that it enables a smoother delivery for those times when you are trying to cope with sub-optimal grip by being smooth. (As opposed to dealing with it by rocking back and forth to throw weight onto your back wheel as you mash the pedal.)
Rocketdog, I had read that the flat spot allows your knee to accelerate through the 'dead spot' faster, which means the rear wheel sees less time in the dead spot and more time in the 'power' phase. Basically smoothing power delivery.
I *think* I can see the sense in that, although like all oval chainring science it seems a little spurious.
All I know is they feel good and my knees seem to like them. Maybe OP's pedal stroke was already perfectly adaptdd to round rings and ovals just messed it up?
Sounds like mumbo jumbo to me, I hated the wonkey rings I had on my single speeds. But one gear does amplify the pulsing sensation I expect. Round felt much smoother
They are bollix. Been a roadie for over 30 years and this Oval/biopace(from 30 year ago) crap is no use to us normal folk. I've been MTB last 3 years and can't believe the crap. I'll stick with 'round'.
It's the latest snake oil. Simple.
Thank f3ck for this post ! I thought it was just me that thought they were a waste of time,as for better traction, maybe if you're a jerky pedal stomper with no leg strength & the "flat spot" just feels like I'm wasting part of the pedal stroke to me.....
Tried one on every bike I own went straight back to a round one after a week of not getting on with it
I've got 2 bikes one with 32t round ring and one with 32t oval.For the last 5 months in the colder weather I've been using the round ringed bike with no knee issues at all .In the last month I've started using the oval ring bike again,and an old weakness/injury in my left knee is back causing a progressive tenderness/ soreness.
It's feel the to me like the deadspot at the top and into downstroke is causing successive impacts to my knees as I power through it to where it ramps up the torque,it's more noticeable on fast spinning/lighter torque riding where it feels like there less pickup in my rear hub than it actually has-feels like the freehub is slapping a bit with each pedal stroke due to the pulsing nature of the oval-perhaps I naturally apply my own progressive power from the top of the stroke on my round ring and that suits me better.
Better traction can result from having an effectively higher gear during the downstroke.
Been a roadie for over 30 years and this Oval/biopace(from 30 year ago) crap is no use to us normal folk
Biopace is the complete opposite of oval rings.
I find they help on technical climbs, I am on a hardtail with flat pedals, sometimes the back wheel might stall on a rock or root and it is much easier to get it going again with the oval.
I don't think you will notice a benefit if you are trying to spin circles and or pulling up on the back stroke as they are designed around a proper pedal stroke.
I had the same issue, knee pain with oval rings, none with round rings. I found the power delivery uneven on technical climbs. According to absolute black, I needed to retrain my pedalling style as I was adapted to round rings. They do appear to work for some people, but not me.
Don't like them either. Haven't used them since bio-pace!
Just to mix things up,I now use oval rings as they massively reduce my knee pain! Lol
Don’t like them either. Haven’t used them since bio-pace!
You mean you've never used them.
This isn't too controversial. Had some similar issues and stopped using them. Physio (cyclist and fitter too) was very against them. The basic explanation he gave was...
You're increasing the load at the most powerful point of the pedal stroke. At that point, the hamstrings are doing a lot to stabilise the knee. However, now you've increased the work they've got to do to stabilise the knee at an even more localised point, since you've increased the load vis-a-vis the ovalised chainring.
What's likely happening, is that by using the ovalised chainring is that you're loading the knee beyond the point at which the hamstring can stablise it. The result is knee pain.
There's a long, long list of world tour pro riders who use ovalised chainrings, got knee injuries and never used them again. Never seen a solid peer-reviewed study that supports the idea they actually improve performance.
According to absolute black, I needed to retrain my pedalling style as I was adapted to round rings. They do appear to work for some people, but not me.
Also, really?
That's just an admission that ovalised chainrings do not naturally align with the bio-mechanics on the body. I mean, I agree, but amazed they'd actually say that.
That’s just an admission that ovalised chainrings do not naturally align with the bio-mechanics on the body. I mean, I agree, but amazed they’d actually say that.
Well not really, arguably he could have adapted to round rings by learning to pedal perfect circles, i.e. applying the power evenly throughout the pedal stroke. In which case, kudos, but obviously that means working the knees differently at different points of the stroke.
If you then jump to ovals which effectively lower the gear slightly at top and bottom dead centres, but continue to pedal perfect circles, then you will overcompensate at the low points of the oval and push to fast through to the next high spot, maybe giving the effect gravesendgrunt described.
Not sure about the localised high gear statement, I switched to Ovals at the same time as trying to spin lower gears anyway, so that would obscure any effect, although I'd argue the whole POINT of ovals is increasing power where the knee is most strong, so arguing you shouldn't do this because the knee isn't strong ENOUGH at this point is a bit confusing, that's not the fault of the oval ring, that's just pushing too big a gear.
Also there may not be any studies showing an increase in performance, but I never expected any, it was all about 'marginal gains' in reducing sore knees 😉
Disclaimer: I'm still agnostic about them, not 100% convinced by the science etc. but do know they feel good on the bike and happen to co-incide with a period of happy knees, so that's good enough for me!
Edit: Disclaimer disclaimer: although I like them etc. I did just baulk at paying another £75 to switch out the big ring on my second/winter/commuter bike, even though arguably I do more miles on that one. Suppose I should try doing back to back big rides on the two bikes just to see how I feel afterwards...
After seeing this thread ,I took off the oval and put the round ring I had run before back on.Early days but it feels so much more solid and nicer to pedal using a round ring for me where I can control the torque I'm putting throughout the full downstroke myself rather than having a sloppy spot up and over the top and into the downstroke.
What ollie53 describes above is exactly what I was feeling - I guess different things suit different folks.
I didn't really notice my knee much on todays ride - which is a good thing.
Every time I read a thread like this where there is a 50/50 split between positive and negative opinions my conclusion is always the same...the component makes no difference whatsoever and any perceived difference exists only in the mind of the user.
People seriously think the new ovals are the same as Biopace? Dear oh dear.
Maybe, here's a theory, your knees are [i]used to[/i] years and years of round chainring pedalling.. and it's the change to something different that has caused the issues? Not necessarily the format of ovaly chainringness?
I've got thoroughly screwed knees from playing football in middle age, but oval chainrings on road and mtb have made life better for my knees.
our knees are used to years and years of round chainring pedalling.. and it’s the change to something different that has caused the issues? Not necessarily the format of ovaly chainringness
This. It's not like humans ahave evolved on round chainrings.
That’s just an admission that ovalised chainrings do not naturally align with the bio-mechanics on the body. I mean, I agree, but amazed they’d actually say that.
I don't think riding a bicycle in general actually aligns well with the bio mechancis of the body reagrdless of the shape of your chain ring.
Every time I read a thread like this where there is a 50/50 split between positive and negative opinions my conclusion is always the same…the component makes no difference whatsoever and any perceived difference exists only in the mind of the user.
from this i can conclude that conclusions are not your strong point.
from this i can conclude that conclusions are not your strong point.
That may be true but it doesn't mean I'm wrong. You never get heated debates about whether or not disc brakes, suspension and dropper posts etc are a good idea. Instead you get 1 or 2 beardy weirdoes claiming that their rigid penny farthing Is the best thing for riding down Snowdon on...everyone else agrees. If there is no consensus from such a large pool of users about whether or not something is beneficial then any effect (if it exists at all) is most definitely in the noise and not detectable by most humans. Consequently not worth bothering with unless you are really anal. As it happens I am a bit anal - I have wonky chainrings on 2 bikes! They do sod all its brilliant!!
If there is no consensus from such a large pool of users about whether or not something is beneficial then any effect (if it exists at all) is most definitely in the noise and not detectable by most humans.
You mean the 19 people who have contributed to this thread? Not exactly a large pool of data. If you read the thread you will notice that majority of posters actually noticed either a positive or negative effect.
You mean the 19 people who have contributed to this thread?
....and all of the hundreds of other inconclusive oval chain ring discussions that have happened on here since they came out
But I like that you counted all the people that have contributed - that is properly anal. I can definitely see why you bought one 🙂
So, what ndthornton is saying, is that the coming and going of the knee pain is purely coincidental.
I'm good at conclusions, me.
….and all of the hundreds of other inconclusive oval chain ring discussions that have happened on here since they came out
I bet if you actually bothered to analyse them instead of drawing a conclusion and fitting the data to it, you would probably find that the majority of people who have posted about them do so because they have either had a positive or negative experience with them.
The idea that if 50% notice a benefit and 50% notice a problem that these all cancel each other out and no one noticed anything does not fit with any thread i have seen about oval chainrings.
But I like that you counted all the people that have contributed – that is properly anal. I can definitely see why you bought one 🙂
It says at the top of page. You might of missed it as you don't appear to of read any of the posts
The idea that if 50% notice a benefit and 50% notice a problem that these all cancel each other out and no one noticed anything
that's what I'm suggesting yes
I like the ovals on the cyclocross bike but not totally convinced they do much - perhaps on some very high torque pitches. They at least do no harm, though, for me.
I think it's significant that you don't see them much on the timetrialling scene (IME). If the bollox currently on the front of the absolute black website was to be believed, then every tester in the country would be running them, 100% no question. Given that your average timetriallist would shave their balls if they thought they'd get 5 Watts out of it, the claimed improvements to efficiency, cadence, power delivery etc don't sound very credible.
Well this is eye opening. I just thought they helped the chain not fall off on a 1x setup. Got one on my bike and can genuinely tell absolutely no difference from the round one that it replaced.