Do Oval (non-round) chainrings improve one leg vs two leg cycling power (Q ring, osymmetric) 

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Personally, I prefer a round chainring and oval wheels.

This is exactly what I was looking for. A scientific, impartial and well informed study on the topic. Thank you. Subscribed

I appreciate him being aero for the vid

Here's my entirely un-scientific take on oval rings: I've been riding and racing for 40 years and 3 years ago switched first to Q-Rings and more recently to Osymetrics. I have partially torn lateral ligaments in one knee and a dodgy pelvis following a fractured sacrum. Riding with ovals has got me back on the road riding, and back to a decent level of fitness. I live in the Alps so most of the riding is long climbs, but there's a bit of everything here. I tend to ride around 85-100rpm, and particularly like oval rings on long climbs. They put less stress on my semi knackered knee when at its most bent in the pedal cycle, and I can ride consecutive days without pain. If I put an eyeballs out sprint through round rings, my ligaments need rest for a couple of days, but with ovals they're ok. Same thing if I have to grind on a very steep section of a climb. So I ride ovals. Now onto the negatives: here in the Alps I need either 34-50 or 36-52, but this number of teeth difference on the chainset is right on the limit of what's possible for the front derailleur. With Q-rings I always found when on the little ring to little sprocket, the chain gets half picked up by the big chainring half way through the pedal cycle. In fact it even happened on the 3rd smallest sprocket when on the small chain ring, like a kind of chain slap against the big ring. No matter what I tried I couldn't stop that, but I rarely want to use those gears anyway, so no big deal. With Osymetrics I don't get this, but the big ring to biggest sprocket is unusable due to terrible chain rub. Big ring to next biggest sprocket it also a no-no due to chain rub, and though it still rubs on the next sprocket it's bearable. I have to be in 4th gear on the cassette before there's no rub in trim position with the front mech. I'm using a Shimano Dura Ace 9100 front mech, and have adjusted it SO many different ways, also with bike shop help, but there's just not enough difference between the outermost front mech setting and the trim to make it work smoothly. This is because the chain line on an Osymetric changes enormously as you rotate the pedals, way more than on round rings, and way more than Q-Rings. Oh for an old friction lever for the front mech! Maybe SRAM Red might work better, the front cage looks a tad wider. If anyone has any experience with this, do let me know. You also have to set the front mech backwards a way with a shimmy on compact Osymetrics otherwise the chain rubs on the very bottom of the derailleur cage. You have to be a die hard advocate for these rings when it comes to front mech set up: I'd dearly love to know how Chris Froome's mechanics set up his front mech! I daresay much of the time he's on 38-52/3 which is much easier for the front mech. Q-Rings are much easier in this respect. But I find the Osymetrics are more natural to use, and didn't notice them not being round when I first tried them, whereas with the Q-Rings I did. But maybe I was already semi 'oval-adapted' when I tried Osymetrics.. At the end of the day, at the age of 55 I'm getting PRs on Strava segments I've been riding for years, and am enjoying cycling without pain, so I'm sticking with my Osy's.

For me as a mountainbiker it becomes easier to climbe steep technical terrain without having to get off the bike. That is a clear and obvious advantage for me. I.e. Most of the time it does not matter, but for situations where I have very low cadence in technical steep uphills I mange to make climbs I did not manage before without having to get off the bike.

units for torque are Newton-meters, not 'nanometers' (3:42)

I purchased an oval chain ring to solve a unique problem while cycling. Towing a trailer with kids. I found my round chain ring was constantly making the bike bounce on the trailer hitch and the kids didn't like it either. So I have the oval ring orientated so that it smoothens the power delivery rather than tries to extract extra muscle advantage. I also ride with clipless pedals, so I have no up stroke to help spin a smoother power delivery. As a result I discovered something really interesting. Less seat fatigue as I'm not bobbing up and down so much and it's really comfortable. Also I find myself using a higher gear when peddling. So I reckon oval chain rings bring a whole new set of parameters that can be explored. It would also be really interesting to test with a combination of crank arm lengths. Does feel strange at first. Pressure on the pedals are more linear and thus give more a feeling of being planted to the bike.

The "dead spot" in a pedal stroke is not considered the upstroke, because as you have correctly said, the other foot is travelling down. The dead spot is the horizontal translation of the foot between the upstroke and downstroke, or between the downstroke and upstroke. This segment of the pedal stroke also generates very little power, and is where the cyclist will generally lose foot speed (fractionally). Non-round chain rings aim to make this segment of the pedal stroke FASTER by reducing the torque load present during the translation, the same way foot speed increases in your small ring. So on the Vertical portions of the pedal stroke you have max torque (56T equivalent) and on the Horizontal portions of the stroke, you require less torque to "reset" back to the power portion of the stroke. Your pop up data showed this, but you're interpretation is off.

It really doesn't matter if they work or not. If they make the user 'Feel' like they work (placebo), then they will be more inclined to ride harder and actually improve.

The upstroke phase only exists for a single leg. We pedal with two legs offest by 180', so the weak point is not during an upstroke or a downstroke of either leg (which are the same thing), but inbetween those strokes. To make it simpler and using the right leg for reference - the weak point is inbetween its down- and upstroke.

I think it's not a matter of if ovals produces more/consistant power, it's that ovals harvest energy from the rider more efficiently. It's the same thing as when like a rider shifts up or down a gear to make the best use of their power output. An oval chain ring shifts up and down and up and down with every revolution to best match the power being out put in each section of the stroke. That's why all of those studies are inconclusive, they're measuring power when they should be measuring power efficiency.

Erm we totally missed the point here - there are no 1 legged cyclists, so the dead spot is not when a leg lifts, it's the point when both legs change direction, so a good orientation would be one which approaches going up stairs, so low gear at top/bottom and high gear through pedal stroke (each stroke is the other foot's return)

I'm just lifting my leg on the upstroke, as long as I'm not pushing down on the upstroke I'm happy.

"The pedal velocity is slower on the up-stroke than the down-stroke." That's physically impossible, because one leg's up-stroke happens at the same time as the other leg's down-stroke, and the cranks are fixed in position relative to each other.

I agree with his main point at the end of the Vid, is find what works for you. I have gone back and forth between oval and round rings, for me it's been more about gearing and cadence. On my Mtn bike with a 1X11 set up I have been running 11-46 cassette with a 30T up front but just didn't like how it felt in the middle of the cassette when standing and sprinting up hills. Using a 11-42 cassette with a 50T expander cog I was able to go to a 32T up front witch suited me better over all. Since I really like this gearing I still am interested in trying a Oval chain ring to see what I think.

I do appreciate the though put into these vids though. Thanks and keep 'em coming!

FFT, Your use of measurements instead of opinions , in general, is the most truthful approach, and the one most faithful to "Engineering" methods in science. You have used the mechanical and gearing analysis very well enough. Thanks. ... However, The physiological process of Cycling bicycle pedals around is kinetically more complex than can possibly be presented in a short video presentation. ... The ability of the muscular body to "adapt" to various mechanical apparatus is very great, and could possibly over power any new devices attempt of "helping" the body perform better. I have 40 years of club cycling experience, and I have adapted to the "Round" chain-rings. My cycling buddy has 30 years of Recumbant Cycling, and he has adapted to that. As you noted, the "Adaptation" ability of the human body is extremely great ; ie, given time and practice, the human body can adapt to "Round" and/or "Oval" chain-rings. The body can adapt to "Ankling" and "drop-heel" pedaling techniques. In Triathlete circles, the body can adapt to "Running-on-pedals" techniques and aerobar positions. ... Not considered is the Varying Amount of Effective "Muscular Pull" that can be provided by the "Muscle Fiber" and "Tendon-+-Joint" combination. This is a Linear Torgue concept. The Muscle Fiber combined with Tendons does not produce "Linear Torgue". And, when the Tendon wraps around a bone joint, the action is even less Linear. ... Here is a little mental experiment to demonstrate this concept of kinetics: (1) Visualize the muscle fiber extended in a bicep curl (arm straight down at 6'clock) ; then (2) Visualize the muscle fiber fully contracted (arm full up at 1'clock). (3)(a) Muscle Fibers "extended" are pulling 'in-line' with possible motion of the tendon. (3)(b) Muscle Fibers "contracted" are pulling "cross-wise" to the possible motion of the tendon. Result : Muscles do not always provide "linear pull" to the tendon. ... Then (4)(a) Visualize the Quadriceps muscles at the top ( 1'clock) position, fibers fully extended; (4)(b) Visualize the Quadriceps muscles at middle (3'clock) position, half contracted; (4)(c) Visualize the Quadriceps muscles at bottom (5'clock) position, fully contracted. Result : Muscles do not always provide "linear pull" to the tendon. ... Summary: The available muscular torque , simply considering One muscle group and One tendon attachment, shows that the muscular activity of Cycling bicycle cranks around is very complex. ... All of us should be more humble in proclaiming our "well-intended" Opinions and Expectations concerning "Oval" vs "Round" Chain-Rings. ... I hope that FFT will continue to Explore and Measure the complex activity of Cycling. ...

You continually keep referring to the down stroke and the up stroke of the cranks. You need to remember that a cyclist is a "two cylinder" pedaling machine. To discuss this phenomenon you should be considering whether a rider should pull up on the up-stroke. You may be aware of a chain set that didn't connect the two cranks: the descending leg couldn't lift the ascending leg. This was so the rider would "learn" to lift their training leg. The rider had to lift the weight of their leg, crank and pedal from bottom-dead-center to top-dead-center. Oval chain rings make no attempt to address this issue. It is an undeniable fact that purely due to Newtonian physics that energy can be saved by reducing the linear acceleration of the rider, bike and rotational acceleration of the (fly) wheels twice per revolution. Additionally energy can be saved by reducing the deceleration experienced each half crank revolution at top and bottom dead center. Oval chain rings are an alternative or addition to a more even application of torque to the rear wheel through the pedaling technique often referred to as "ankling". There is definitely a measurable and worthwhile advantage to be gained. One of the reasons for the adoption of higher cadence climbing is that the man and machine aren't continually gaining and losing so much momentum at each slow pedal stroke: It's like having more, smaller cylinders in a car engine resulting in more but lower power pulses per rev. Oval chain rings aim to improve on this further. At top-dead-center a lower gear is effectively used (smaller chain ring) so the cranks, (not the bike) speed up and pass through this segment quicker. Similarly a higher gear is engaged (bigger chain ring) on the down stroke so the more powerful push and resulting torque lasts longer. Even though this is the most powerful crank segment, the bike, rider and wheels are discouraged from forward acceleration as the big gear can't be "wound up" immediately. The question is, can the body in all its complexity adapt to take advantage of these tangible gains? I think it can but: a). riders need to learn to adapt to the different pedaling action and b). the current on-bike power meters are not accurate enough to indicate the small difference in improvements. A static Watt Bike probably is but I don't think riding a Watt Bike is the same as balancing a two wheeled bike under normal ride conditions. Can the resistance on the Watt Bike mimic the inertia of the bike / rider combination plus wheels out on the open road? We may be only talking about 0.2% of any given 0.6 sec revolution (at an average 90 rpm) but consider that Andy Schleke lost the three week long Tour de France by 39 seconds. (over 6 hours /day for 19 days this equals 410,400 seconds. The 40 sec.to win =0.001%)

These videos are usually great but this is a real disappointment. The fundamental question of whether asymmetric rings enable a rider to produce power more efficiently is not answered. There also seems to be a lack of understanding of what the dead spot is and what mechanical advantage and disadvantage are. The dead spot is actually a combination of the points over the top and under the bottom of the pedal stroke at which the mechanics of the body make it unable to exert force efficiently through the combined effort of both legs simultaneously (hence the reason it's a dead spot), not on the uplift for which the opposite leg provides the majority of the power (as stated but not properly considered). We ride with two legs, so discussion of one legged power production just muddies the water and belongs in a separate analysis of pedaling technique.

You have some cool graphs!

Very good. As far as it goes. However, one additional point which is the Raison D'être for oval (and biopace) rings. The large diameter is to accommodate the strong part of the cyclist's pedal stroke and the small diameter is to accommodate the weaker part. Taking a close look at the way this is to be used to advantage, we see that the all-important transition from the weaker to the stronger position occurs between the, say, one o'clock and four o'clock position of the crank. Here the leg is beginning its downward thrust, building up strength, and easing into the peak at four o'clock. Human muscles don't like sudden changes, this is called 'gracefulness' in the dancing art. I enhance this effect by dropping my heel early and getting a head start into the downstroke. But then, I am sure my cadence would be considered too slow for your discussion, which seems to be more racing oriented.

Thanks for this. I ride two bikes- one with Q rings and one with round. There isn't a massive difference. But... you don't really cover the possibility that the power is the same but the cycling is less of a strain on your joints. My knees are certainly happier on longer distances using the Q rings but that maybe just me.

Several points - there are one-legged cyclists, like the fellow who did the Moab 24 Hr years ago, passing two-legged riders on uphills before dismounting and hopping past on the steepest stuff. Second, two legs joined by the crank show a two-phase cycle, where the primary foot is pulling the other thru the weak part; riders on flat free pedals are only applying force downward, and the other is along for the ride on the upswing. The alternate muscle groups are enjoying a rest cycle during the arc where they are not active, so flushing blood in and out is a part of the phases. Cadences and apparent gear ratios/leverages are all trained and optimized for output over fifteen second to ten hour periods. A single rotation cycle means very little. How much less efficient is the old toy pedal car, which some have tried to adopt with no success, to the bicycle drive train?

I've never felt like they made me go faster, I've only felt that it makes low RPMs easier, and high torque riding less tiring than round rings. It's more of giving your legs an ever so slight rest and shortens the effort period per revolution.

The weak points are when the pedals are crossing over top and under the bottom (either leg), just like alternating electrical current. The narrow part of the ring gives an effective lower gear at these points giving the legs a little break at that point. Way back it was shown that the efficiency only appeared a low cadence-right where my old legs like to run (I don't race).

Its about balancing off the dead spot with higher gearing, whilst maximizing torque on the down stroke. The up stroke is more about taking off the weight of the upward leg so that the down stroke is maximized, not having to push the weight of the upward leg. Thanks though for the very valuable insights.

subjectivity is still an important characteristic of the human species. If the result of wearing a green shirt makes you happy then it works. Not everything we do need scientific qualitative support (nor can it be measured). Great video..

I hung onto every word there. Thank you for the not inconsiderable effort you put into this vid. I have enjoyed it. Now I just need to find out which size chain rings are best for me. Easy as that then.

I found in RL, that ovals work better for grinders, and spinners should test before using. Grinders have enough time to take advantage of the gear change, but it just gets in the way of spinning.

I don't care what they all say , the proof of the Pudding is in the eating . I have an absolute Black Oval 26t on my mtbike when climbing and I push down I feel the most resistance coming in at about 3.o'clock and push harder with the pressure coming off at the bottom of the stroke at the same time the other leg feels like it's floating up to the top no effort and still relativity easy to begin the down stroke. For climbing in your low gears they are better , also I think your legs become stronger as well, as on the power part your sort of on a bigger chain ring and your legs start to adjust to that, my original chain ring was a 24t so I really jumped up to a 26t and on the 3 to 5 part it's a 28 but you don't feel it. Best thing I upgraded except for my Dropper post.I ride with flats. I forgot to say that I start my down stroke just before the pedal reaches the top by lifting my leg and pushing it over the top.

A very un-biased account on the long debated topic of Oval vs Q-Rings. Being a previous convert from Oval to Q, I have now found myself returning to the Oval, I was forced due to needing more teeth going from a 55T Q-Ring to 58T Oval, allowing me to maintain a better chain-line through the drivetrain. It will be interesting to monitor the progress over the coming winter months.

Take in account that the human body is not a machine solely based on mechanical functionality... I felt a overall “smoother” more pulsing than charging stroke and considerably less fatigue as well as increased traction on technical steep climbs, which results in a more consistent movement. Oval chainrings do help at least for me and in mountain biking.

I have a Shimano Biopace Fc-M350 170 mm, i have purchased my used beloved bike two years ago with 80 Euro, actually i had no idea that the crank was oval shaped lol , but i choosed this bike among hundreds of other bikes was there because i felt so comfortable when i tested it, nowadays i have upgraded my bike, i upgrade every thing except the original frame and the nice old crank, i even turned it to E-bike with 1000w, its a monster now, glad i didn't changed my old crank.

Someone should 3D print a 53-8 oval chainring just so we can put it on for laughs.

i think a lot of folks just use the wrong length cranks, and that is why they detect such a change when using oval rings. almost everyone regardless of height uses 170-175mm. I am 6'3". recently swapped my 175 cranks for 152 cranks (well short for my 34" inside leg). I am already running non-standard chainrings, and have never been tempted to go back to "standard" sizes - I run what suits my riding, not what is fashionable. with the 152mm cranks my cadence shot up, and Strava PRs occurred left right and centre. folks need to sort out gearing and crank length first before even worrying about stuff like oval rings. but many folks just buy a bike and copy some or other "pro", without looking at their own circumstances. fashion always stands in the way of science, and this is no exception.

I have just ordered a Rotor ALDHU Carbon Crankset. A 53/39 bigger gears 2 build power . I am an old guy & l spin . Souplese as the French Say . Also ordered a 52/36 & may order a 50/34 . I have always ridden round Chain Rings . Have ordered 11/30 & 11/34 cassette Rotor ALDHU Crankset looks like the most Commonsense approach 2 replacement / swap out of Chain Rings Question time ⏲️. Can u sprint on Oval Chain Rings ? Nice Job here by u on RU-vid. Always gr8 value. Robert Australia 🇦🇺

My experience: I have Osymetric 52-42 and I feel that my climbing ability is improved, especially out of the saddle. When you're basically "hammering" out of the saddle, you have your entire body weight pushing down on the pedal and very little upstroke or "scraping gum off year cleats motion". So gaining teeth on your chainring out of your saddle would benefit. Seated pedaling in the saddle is less efficient for me. Very short upstroke with higher cadence makes it difficult for me to focus on any pulling motion. Sprinting is terrible for me with Osymetric. Although you are more hammering than focusing on complete stroke, I find the larger down stroke duration makes if difficult for me to find the right cadence. Maybe I need to spool up to a faster cadence. I want to see if it's possible to run a 53 round outer ring and a 42 Osymetric inner ring. That would work best for me.

if you pedalling with one foot its a disadvantage in the up stroke but we pedalling with tow feet .

I don't know how to explain but I can feel the big difference when using Oval. I ain't going back to round. Its helps a lot especially in distant riding.

Interesting vid, although I'm not sure that we 'finally have the truth'! Until a proper, large scale, accurate, impartial test is done, we won't get the truth either, but such tests are expensive and time consuming. Personally I run a 36t Q on the inner ring and a 50 round on the outer, it's what works best for me.

What's the term used for setting both crankarms to the same 12 o'clock position? Effectively converting your bike to a rowing maching where both legs are engaged on the downstroke

i have tried these and they do feel like they smooth out the pedal stroke, but what i don't like, which is commonly agreed, it does sacrifice front shifting smoothness

Trying now on mtb Absolute Black oval chainrings. This weekend i'll have a race with them. On a short trainig yesterday, what i found is that on flat they are super smooth to ride. Like we are not making great effort to build up speed. But i'm still a bit sceptical on technical terrain or on climbs. Maybe is because i'm not adapted to them, but they seem to be a little "laggish"... Well, i'll give it a try

Another excellent video. Hope there's more of these planned!

I have used both, and I must say that personally years ago I used the 90's Cannondale with a "Biopace" and loved it, and now a days on my Specialized Tarmac I used an Oval-Titanium chain ring set, 14%-16% settings to choose from, and it works for me like a charm... very effective on these Spanish steep roads! It's basically a very personal choice, just don't listen to the mumbo jumbo of what everybody has to say about Oval shaped chain rings, you have a doubt, just try some, for a month or two, do your 80-100 kilometer rides then decide if you like them, or not... Simple as that!! Do what ever works for you because when you're on a hairy hard ass climb, it's just you and your bike, and when you finish your daily training/riding, you will know, believe you me lol

Very informative. I'm interested in the correct spelling of the chainring brand you introduced as Oquval or Oguval. Tried searching for it. My ascertion is if you're going to do something do the highest degree to completely apply the principal. You introduce this as 40% oval to round. Well I'm willing to try and experiment also willing to share results.

Ill stick with a round one,it fits nice in my mrp chain device,it would be pointless with an oval ring,youd need the guide block and jockey wheel slackened off,that defeats the point of its purpose If i had an xc or all mountain bike id rather stick with the triple ring set up for hills,i tried one on a triple ring set up,wouldnt work with the front mech,i had xt bio pace years ago,that was a lovely set up for climbs,you could drop gears,unlike oval narrow wide chainrings

I think the oval effect should be most pronounced at a low cadence (50-60 rpm)on the dead spot (bottom) of the stroke, when one leg is at full extension and the other knee is fully bent. At a high cadence it will just be like a round chainring, becuase the changes in chaninring diameter will be too fast to percieve.

you don't get a greater advantage with a bigger chainring, it is the opposite. put a bigger chain ring on and the gear ratio reduces, put a smaller chainring on it gets easier to push, because it is a relationship between the crank length and ring size. Therefore you have a greater advantage when the ring is at its smallest, when you feet are top and bottom. At these points you can produce less torque but you have a greater advantage. i.e. gearing is easier. Therefore it give you a move consistent spinning action and power delivery compared to a power peak at 3 and 9 o'clock and power low at 12 and 6 o'clock

So what you're saying seems to imply that, in order to take advantage of the theoretical faster return-to-power position on an oval ring, a rider would have to change their RPM from slow (power zone) to fast (dead zone) 2 times every 360 degrees. This does not seem likely, as I believe that given the high RPMs road cyclists generally pedal at, momentum keeps pedal RPM relatively even, negating the advantage of oval rings. One exception might be low RPM climbing out the saddle.

Should be also mentioned that they often won't work perfectly with most front derailleurs

Missed the point. They are designed to decrease fatigue by lowering MA at dead spot, not increase power output. Shimano's Biopace was supposed to increase power at the dead spot.

After riding mountain bikes for 20 years, my pedal stroke is almost completely quad dominated. I do not spin as effectively as other riders. If you do spin uber effectively, an oval ring probably wont seem as helpful. For someone like myself, I believe it increases the load where I am strong and reduces it where I am weak. Is it a good idea to go this route? I ride for fun. The further and faster I go, the more fun I have. If the oval ring can help me in these areas, its worth it.

The "peanut' shape power curve is caused by the two legs. I don't think you can move to practical consideration without always considering both legs. So you have take your sine wave, double it and shift it 180 degrees. of power 54T on power down, but only 8T on the lift up of that leg, the net result when you combine the two legs is 54-8 = 46T and the narrow part of the peanut is when the feet are at the top and bottom, so that might be (I'm guestimating now) maybe 36T. But then you have to consider momentum with further evens everything out. So I can see where bright people, and bicycle engineers, can reasonably disagree. I've been peddling a Fisher HooKoo E Koo (I guess 1987) with a Biopace eccentric. My results.... I don't really know. It's okay. I think for a duffer like me, an eccentric chainring is probably the most helpful on steep slow climbs, where a couple of teeth (leverage) one way or the other makes a big difference. One RU-vidr mentioned this. 7:15 You're discussing climbing. The test of a possible benefit of the eccentric chainring? Video riders peddling up steep slopes right at the point where they crap out. If eccentricity is useful, then those riders who crap out will be doing it when the peddles are top and bottom and they just can't get the peddle to where they can make that down stroke. Eccentric rings should show their value (if there is any). Consider a climb where you can keep going with 34 teeth, but not with 36. Eccentricity gives you both. 36 where you have maximum power and 34 where you don't. Overall cycling I think it is more effective to keep a steady 60-80 turns/minute pace, and even out my peddling: moving towards the 'sausage' of the professional cyclists. Bottomline: The real lesson here I think is about leverage. And not just for cycling. There are some eccentric 'fulcrum' levers, more mechanical advantage at the beginning, but as you lift the mass and moving its center of gravity (think of tipping over a rock) it becomes easier. I'll try to keep your video and my random thoughts the next time I'm thinking of simple machines. Really smart video. Well done. You said, "you only notice when you change between oval and round." Ding! Okay, I have strong legs, I think I 'muscle' my old Hoo Koo E Koo a lot more than rented and borrowed bikes where I keep an easier gear but a faster cadence (and I think I also keep a more consistent cadence). I'm thinking about getting a new mountain bike. I want a very low gear for climbing, but oval or round? I won't worry about it.

Hi. How are you doing? I am thinking to buy a chainring QXL Oval 46T, I recommend it?

I'm afraid all you have done in this video is prove that you don't understand what the pedal stroke is (2 legs, power zone to weak or "dead spot"). You have taken a lot of data and rattled off facts not knowing where they apply. For your one legged view, you would need an egg shaped chain ring. If you want to give the really truth about oval chain rings, there is three things you need to do. 1.understand theory behind the design. 2. spend many many hours riding with and without them on different kinds of bikes. (i personally use road bikes and TT bikes). & then 3 understand how and why the oval rings affect your personal riding. - For myself I am settling towards Road bike with round chainrings and a cadence of 90 - 105 (when not inside a peloton). & TT bike oval rings with a lower cadence of 80 - 90. The TT bike I used to use a cadence of 100 - 112 on round chainrings. The bottom line is which can get you from start to finish the fastest. (PS as a triathlete I have to be able to jump off the bike and run.) PSS I just had an idea for you. cut the oval ring in half so that you have the crank followed by the half a chainring. now apply what you said, forget the up stroke. pedal from top (weak point/deadspot) down through the horizontal (power or strength point) to bottom (weak point) now you may understand the theory better. ( Osymetric (Cam shape) simply have a different belief on where the most power is produced through the stroke )

Absolutely great informative analysis and presentation of the data.

Very well thought out and researched. But you are forgetting one thing, they look cool as... :)

Many years before Rotor, this idea was tested on bikes, and didn't function then. I would like to try one though. Finn. Denmark

Nice tip coach

Regarding your statement on adaptation... I switched to oval rings on my primary bike over two years ago (Q-rings initially, now AbsoluteBlack). Initially I felt a perceived improvement in speed and power. When I got a dedicated commuter bike that I kept round rings on it became apparent to me that there is little difference. Basically, I feel no difference when I switch back and forth between the two...

The upstroke isn't 'the dead spot' as the other side is doing the down stroke at that time. It's around the 12 o'clock 6 o'clock position. So all that waffle right there was most probably all guff.

Really valid point at 11:12 Good stuff

There is a real different noticeable if you ride daily climbing hills 10% or more grade. I meant daily. Compared between Oval Biopace and Round Chainring results in real different. Quite alot.

Due to the fact we're Bipeds...I'd like to know the difference of Downstroke advantages to Upstroke disadvantages, and whether the force in the Downstroke advantages of the sum of both sides negates the Upstroke disadvantages ???

I've been riding bikes for 40 years and never, not even once been able to develop muscles soreness or growth in my calves. Until recently when I tried some ovals and couldn't walk straight for 4 days... What is the go with that.

We have been told about a new oval chainring from France. Plateaux ovales - Dual-Oval dual-oval.com/ We have no experience with these or their shape but they look interesting.

From the point of wear and tear of the knee joint, ovals are better, not having to push so hard when the knee is bent most is an improvement

I'm using an Absolute Black 34t oval inner ring and a round outer ring on my Ultegra 11-speed setup. Shifting with the front derailleur has been flawless requiring no adjustments. The difference between a 34t oval and a 34t round is not really noticeable other than it feels like I pedal smoother with the oval ring. I am considering an oval outer ring also.

Oval chainrings offer much better advantages in mtb, the smoother output reduces the breaking of traction on loose ground, it genuinely helps with the dead spot issue when on very steep inclines

Does this take into consideration the larger muscle groups can take the added stress in regards to endurance?

If they're basically supposed to change the gearing at various points of the pedal stroke, then why doesn't the rear derailleur pulley cage move? I mean, if you change the bike's gearing in the usual way (with front and rear derailleur), the pulley cage swings back and forth to take up the changing slack in the chain. Yet every time I've seen an oval crank drivetrain spinning (including in this video) the rear derailleur isn't moving at all?

with oval chainrings you get a greater advantage on the down-stroke because you use larger muscles than a disadvantage on the up-stroke and given that when you're in the up-stroke with one leg you're in the down-stroke with the other you can produce more power

Im going to oversimplify - please bash away - With an oval chainring, we're really reducing the contact point for leverage is shortening and then lengthening ( chainring teeth - chain / and because the center of the crank arm is constant ) maybe thats why INDIVIDUAL gearing is so important..? While PEDALING efficiency IN CIRCLES is a great concept and maybe best used( for comparing left right power efficiency and training to your imbalances)... Please laugh, finger point, whatever... But Im thinking.. "round, you know for kids..!" - hudsucker proxy

I think oval rings are beneficial for lighter road bikes, giving the bike a longer pedal stride, cause less weight will have less momentum at high speed than say a steal frame road bike..? Does this sounds accurate or nah? cool videos btw!

Hi there, in theory can we use crank based power meter with oval chainrings? Will the reading be accurate? Thanks before mate.

i think is not about mechanical advantage, may be it´s just a way to correct a bad peddling technique, pros tested on pioneer pwoermeter reduce a lot dead spots amateurs does´t but with a oval ring can improve their peddling

If u make money of showing us some products thats compleatly fine.. i actualy want that u get paid for this great info. This is pro stuf. Just dont ever sign up for saying shit someone else wants to be said.. stay true to use.

I was trained long ago to pedal in circles, I bought a bike with biopace, yes I'm that old, it provided absolutely zero benefit on any terrain and I replaced both rings after about six months. I ride fixed now so this is a non issue these days. IMO if your pedal in a circle, a circular ring will provide the drive you need.

As a triathlete I dont get thigh cramps as often as I did after switching to oval and my legs feel Less fatigued off the bike so I run much better

Mathematics aside, I have an oval ring on my singlespeed and the bike is far more rideable where I ride which is on coast path trails that are steep techy ups or down with very few flat parts. on a singlespeed the effects of the variable gear size is far more noticeable as I regularly reach the end of my body's torque ability where as on a geared setup that happens far less if ever also by the time I'm trying to grind my smallest gear on 1 x 11 setup up a steep ascent it's quicker just to shoulder the bike and run up so having an oval ring is of little advantage. So for any single speeders or indeed fixie riders there is a definite advantage but for geared bikes it's it's so marginal it boils down to personal preference more than any mechanical advantage.

I was doing my master-thesis about cycling and I'm very happy and pleased about your video! I measured the force that was put on the pedals. A picture that shows the power (picture is not from my study but in my thesis it really looked the same) can be found with this link: bildung.freepage.de/cgi-bin/feets/freepage_ext/41030x030A/rewrite/doc-hilli/VEROEFF/RUNDERTRITT18.GIF The advantage during the downward movement is clear, but people forget the disadvantage that is caused because they leave their leg on the pedal without pulling upwards… but pulling up would lead to a biomechanical disadvantage as you explained and I also would confirm. However people usually keep their leg on the pedal without pulling upwards which causes a negative force and the bigger chainring diameter costs the leg on the other side more power to lift it up. So the question would be if the advantage of the oval chainring really exists or cancel itself?! In addition I have to mention that one person in my thesis was able to nearly avoid the negative forces on the “backside” by lifting the leg so the pedal was unloaded and the efficiency was the highest. For those cyclists I could believe that oval chainrings could lead to a benefit. But due to the fact that there is no 100% proof and Chris Froome is not better in minutes with his oval chainrings to the other riders it is just a nice marketing-thing in my opinion. Maybe someone can make a better thesis about this topic and respects all the parameters ;)

Oval is a winner for me when standing an pedal mashing my ss mtb

Well one thing you mentioned that you could save 1/100th of a second per pedal stroke riding at 100prm, that is a second thus you get effectively an extra second of pedal stroke, thus you could get in an extra 1 pedal stroke or so in therefore you will increase your cadence therefore an increase in power.

Cliff notes: Taller Riders ... More Benefit Shorter Riders ... Less Benefit. Shops resist them because ... ? Evidence is they ARE 10-15 per cent tougher on toes. They work, but the the leg muscles used are different. Science includes crank length AND leg length AND set height. Bike shops shouldn't echo industry on this kind of thing ... they DO work ... if YOU will too. HBFitnessTech #HBChristo.

U17's again, limited gears, what's more efficient and by how much? Large sprocket large chainring (say 51x17) or small chainring, small sprocket (say 39x13) - note the gear ratio is the same: 3:1 for both. Which would you use? Does it matter? and if so, by how much?

Upstroke/downstroke it doesn't matter. What produces the more power at the rear wheel?

Ovalized chain rings only have an advantage on a granny gear going up steep hills. Prevents Flat Spot...

Would it be worth using an oval inner for climbing/lower speeds where you say the 'pulsing' effect on speed is exaggerated? And then sticking to a round big ring where the effect on speed is negligible?

So I have been using a non round small cog only as I get knee pain working on the idea that I would be putting power through when knee is strong and in a good position and reduced power on the transition phase where joint is 'weak'. It feels better and I don't think my knee hurts as much. Any evidence for this or is it more likely that my knee is just getting better and it's a coincidence? I haven't tried going back, gift horse and mouth and all that

Shimano had Biopace (oval) chainrings in the late 80s. I just wonder about the variances in tension on the rear derailleur springs during the pedal stroke with the oval; just watch the rear derailleur while these are used; that's spring tension at work which would add resistance wouldn't it?

At a strictly set application of power (100w, 200w no matter) thru some type of device which also was able to completely unweight the leg weight on the upstroke, would an oval 53 accelerate the rear wheel RPMs faster and then sustain a higher RPM (still at that prescribed power setting) thus resulting in a faster wheel speed than a round 53? My hunch is yes, the cadence will be higher and thus result in more wheel speed with the same power applied in the downstroke. However as the video keenly addresses, adaptation occurs and long time round ring riders are able to scrape the bottom and push over the top and thus benefit from a mechanical advantage at the 12/6 over oval rings. However does the mech advantage of oval rings at the 3/9 outweigh this? I sure would like to see this test.

Incorrect terminology and misguided explanations! It's not downstroke versus upstroke - it's vertical foot movement versus horizontal foot movement. The dead spots are when feet are near the bottom or top of the circle. You cannot have a dead spot on the upstroke, because that's when the other foot is on the downstroke - unless you're a one-legged cyclist (but then the chainring design needs to be very different than the oval designs that were discussed). So the video should have been talking about four quadrants of the circle, not two halves. It's not difficult to improve your torque through the dead spots, where the crank arms are near vertical. We all have experience running, where the primary thrust is delivered as our foot is moving back. Simply apply a "runner's mindset" to your pedaling and engage those same muscles as your foot moves back at the bottom of the circle. Then at the same time, engage the quads a little early to push the other foot forward across the top of the circle.

I think I disagree, maintaining pedal speed...almost creating a sausage shape on the Wattbike makes me generate a lot more power for longer. Because of the oval shape I'm still using bigger muscles more, but I'm not accelerating and deaccelerating as much - surely that is a waste of power....certainly feels like it to me. One other point though....everyone is different I guess. One size rarely fits all

Go to 11:25 for the conclusion.

I might be wrong, but some people might miss the real point of oval rings, I am an amatuer enthusiast rider, dont drive for sports and like to drive fast all sorts of terrains no steep hill klimes tho. But have some problems with knees. some might say krank is too long, wrong gearing or cadence or such, but as I see, oval chain ring might not give mechanical advantage as its stated in this video, but rather mitigate mechanical forces and damage on the knees, hips at those near top and bottom positions. as many people say, you cant follow and obey the charts and stats supposed to be obeyed, some short people feel comfortable with longer kranks than its "advised" by professionals, or opposite, some taller people like shorter kranks ... higher cadence and such, I myself am little overweight, with strong legs and higher slow muscle ratio i think, and feel much more comfortable at 70-80 rpm cadence. As i see and think, oval chainrings might be a solution when you want to push yourself to near max performance and want to lover strain on joints and muscles at those positions they are more susceptible to damage and problems on joints ....

Your shirt looks cool. Which model/brand is this ? :)

The whole analysis of the video is based of the one-legged cyclist. Of course that cyclist has a advantage and disadvantage on the down and upstroke of an oval ring. But with two legs, the key factor is deadspot and more even momentum of the rear wheel during steep mtb-climbs with dodgy tyre-grip. This is not mentioned at all.

I may not have got my head around this properly, but isn't the point about oval chainrings not about the decrease in efficiency in the upstroke, but about the point where the cranks are between the 10 O'clock and 2 o'clock positions where either leg is getting to the bottom of the downstroke (down stroke being where most of the power is derived) and thereafter transitioning the next leg to the top of the downstroke a bit easier/ quicker so the next leg can push a big gear again on the downstroke? Either way I like this guys vids and look forward to trying my oval chainrings - I went for cheap ass Doval chainrings on Ebay - will see how they go!