Rotor Q-Rings First Look
Rotor’s Q-Ring design is claimed to increase power output, make high cadences easier and soften movement through ‘dead spots’
Posted: 27 September 2007
by Richard Hallett
Marks denote suitable mounting holes |
Spanish cycle engineering is making waves |
Patent on multiple mounting holes |
Non-circular indeed |
Optimum Chainring Position on both rings |
Rotor Q-Rings Shimano 130BCD 53/40 £100.00
Non-circular chainrings have a long and intriguing history that stretches back almost as far as the invention of the rear-driven safety bicycle itself. They have tended to reappear at regular intervals that seem to coincide with the length of time it takes a generation of cyclists to forget the lack of success of its own version of the idea. Shimano’s Biopace chainrings had until recently been widely assumed to have put paid to the whole thing, having been almost universally panned by those who tried them. However, non-circular rings have never entirely gone away, with small-scale production of Egg rings and their like keeping the flag flying, and recently there have been several attempts to revive interest.
The obvious question is, what is so different about new designs? Which in turn begs the question, how are they supposed to work in the first place? Most such rings are roughly elliptical, with a long and a short axis. A circular chainring acts as a lever arm of constant specific length pulling on the chain, whereas a non-circular ring acts as a lever arm of variable length. This is intended to act in concert with the way the human leg generates a variable force on the crank as it follows the pedalling circle; at the point where the leg produces most pedalling force, the elliptical ring has its greatest radius and longest effective lever arm. Likewise, where the leg produces its least amount of force, the ring will have its smallest radius. Effectively, the leg is supposedly enabled to do most work where it is strongest.
Put this way, the non-circular ring sounds like the only sensible way to go, which is probably why it has been so popular with inventors over the years. However, studies have shown, almost without exception, no perceptible advantage to non-circular rings. Indeed, some have even shown a disadvantage of up to 5percent.
Rotor’s Q-Ring design is claimed to increase power output, make high cadences easier and soften movement through ‘dead spots’, so the Spanish company clearly believes its product does what previous efforts have never been shown to do. For sure, they do not seem to have hampered women's world road race champion Marianne Vos, who rides them on the road and in cyclo-cross.
If there is one obvious difference with preceding attempts, it is Rotor’s Optimum Chainring Position (OCP) System, which allows the ring axes to be orientated with the crank almost exactly as the rider wishes. In the case of the 130mm BCD rings tested, there are 35 mounting holes for the chainring bolts; since there are two identical orientations 180deg apart for each ring, this means there are 70 possible ways the ring can be positioned, each just over 5deg apart. To aid with setup, Rotor marks five of these holes, grouped two on one side and three on the other, with punch marks that indicate the suggested five most effective possible orientations. The rider can try them out to find which one works best.
With the 53t ring, the maximum radius equates to a 56t ring, while the minimum radius matches that of a 51t ring. What this means in practice is that the instantaneous ‘feel’ of the ring at either of those points is the same as that of the matching ring size. RCUK found that initial sensations are of notably easy riding, especially into a headwind, at a slightly higher cadence than normal, although cadences of more than about 110rpm are less comfortable than with a circular ring. These are, of course, subjective and by no means conclusive, hence the need for more scientific tests. Watch this space.
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Discuss this story
Hi Guys & Ladies I have been thinking about getting a set of these for some time now so did a little light reading to see if they actually work(logic seems to indicate that they should) tried a search on our site but nothing found until now. You might find this link usefull http://www.noncircularchainring.be/pdf/Biomechanical%20study%20chainrings Enjoy Regards Mike
Posted: 28/09/2007 14:41
Very interesting, although it seems to make the usual claim that non-circular rings must work because they ought to. RCUK will be looking into various aspects of the problem, but there is one that can't be ignored. Since the effective max ring size is 56t, why not simply ride a 56t ring anyway? After all, on the Rotor 53t ring, at the same cadence, you go the same speed in any given gear as on a circular 53t ring. If you have the power to ride a 56t ring at the point where you apply max force, you should therefore go faster than the Rotor ring at the same cadence, since what happens at those points where you don't effectively press on the pedals is not obviously important. One answer, and the one that looks most compelling, is that on the Rotor ring you spend less time in the non-productive part of the pedal circle and therefore more time applying force to the pedals. Conceivably, therefore, you might be able to apply more power over the time taken for any pedal revolution.
Posted: 28/09/2007 15:55
I think, regardless of whether it works or doesn't work. Money could be better spent on something else to improve performance. I find it amusing how oval rings have been around for ages, but no-one ever seems to use them. People see them, think WOW - They think it's a new idea because they haven't seen it before. Why haven't they seen before? Because it's rubbish.
Posted: 28/09/2007 16:27
I thought Cancellara used them at one point. Does he still use them ????
Posted: 28/09/2007 17:17
I dont Know ADAM. Thats a good question and deserves a through debate on the forum. OZ Mat, James - what do you think.....
Posted: 28/09/2007 17:31
Adam I have no idea of your academic qualifications are, but do you not think three chaps with a Master of Science Degree and one in Applied Mathmatics just might know what there talking about
Posted: 30/09/2007 14:52
In most cases, you'll find those with Masters in Science and Maths are very good with numbers, but not quite as fast on a bike. ** Waits for Richard to come on and tell me the people who came up with the idea 427 years ago were some of the best pros the world has ever seen **
Posted: 30/09/2007 18:28
Agree with that statement Adam. Just had another look at that report(been a while since I first read it) and it looks like the Q -Rings are not the best example to be testing, below is the quote from the conclusion at the end of the report. "The Q-Ring is a brilliant example of excellent manufacturing worksmanship but is first and foremost a compromise solution due to technical compatabilities and marketing reasons : ovality 1.10, slightly modified ellipse and crank @ 75 deg. But as with all compromises, this oval is sacrificing most of its potential advantages. The problem with the Q-Ring is firstly its lack of ovality and secondly, the crank orientation. Even with the crank orientation in the optimal position the Q-Ring performances are disapointing and remain very weak" I new there was a reason I never bought a set. Keep on cranking Guys
Posted: 01/10/2007 07:59
Well I have a SQUARE chainset. Well thats what it feels like on bloody big hills.
Posted: 01/10/2007 11:05
'You CAN use a non-round chainring in a fixed-wheel transmission.
Discuss.' You are right, Martin. Usual incisive, informed comment from Adam T. VLAD, you may be on to something there. Call Rotor now. Personally, I am sceptical about non-circular chainrings for reasons stated in the article and post above. No reason to dismiss them without trial, surely?
Posted: 01/10/2007 14:10
It's sruprising in a way that after all this time the question fo "what are we trying to optimise ?" is still difficult to break down. So the article linked is interesting, but who said peak joint power is what's important ? The pro Rotor studies on their site look at things like lactate concentration and heart rate and so on the assumption that lower is better. It may well also be people who've spent years riding round rings can optimise their own spin
Posted: 01/10/2007 16:21
Good points, SloBoy. Just rode the Newbury Sportive 115 miler on the Rotor rings. The only previous riding on them has been a 10 mile TT and couple of rides into work. No problems adapting to any kind of different pedalling sensation. For sure, even after six hour's riding they felt fine and I was still relatively fresh at the finish. Again, it's hard to say without proper testing whether there is any real advantage, but they certainly feel 'nice' when pedalling.
Posted: 01/10/2007 16:51
Blimey Richard, Did you have a lap top with you on the Newbury Sportive whilst riding round. You posted at 1410 and said "can't discuss without trial" You then posted at 1651 and said you have just done the sportive on them. I make that 115 miles in just 2 hours and 41 minutes and that dont include travelling time. SO. You must have had a laptop in your rear pocket whilst riding the course.
Posted: 02/10/2007 00:57
I had another browse through that doc and a few more thoughts: - if the ovalised rings make the hip extension and flexion easier that probably is a good thing cos that's using them big old muscles - the effect is bound to come down to personal limitations. As an especially crap cyclist for the amount of riding I do, I have more time than most to contemplate my own frailities, and in particular, what happens as I get tired. My legs usually feel fine, and I tend to get a sense of weakness in my lower back - I know I've had a tough day out when I can't sit up for my dinner. One might imagine that non-circular rings could probably be tuned to minimise, let's say, fatigue of the hip flexors, and help an old codger like me along the way.
Posted: 02/10/2007 14:15
The great thing about the OCP system is it lets you play around with the position of the rings until you (if you are lucky) find a position you like, which might not necessarily be the one recommended by Rotor. Remember your feet still prescribe the same circular movement and, presumably, still press on the pedals at the same part of the pedalling circle. I am somewhat in agreement with Adam T re the authors of the studies quoted. There is a consistent tendency in the field of human-powered vehicles, of which non-circular chainrings have long been a part, to assume that there is some secret formula to pedalling that can be elucidated through mathematical analysis. There may well be, but none of them has managed it yet.
Posted: 02/10/2007 16:23
Quite so, the confusing factor being the highly adaptive nature of the power source. As you say, all the solutions have a circular foot path. And I guess with these rings, we'd expect the pedal rotation to be at constant rate as well, so you do wonder what they can do that my neuromuscular super computer can't do just by modulating pedal pressure. The Rotor cranks, on the other hand, do things that you can't quite do with the standard crank, in that I think the feet speed up and slow down at different parts of the stroke. On a different aspect, I've always fancied a go on those Powercrank jobbies, where the two sides rotate independently, just to see how that feels. Bit pricey for a curiosity experiment though.
Posted: 03/10/2007 08:47
- if the ovalised rings make the hip extension and flexion easier that probably is a good thing cos that's using them big old muscles I was trying to work this out, if the crank length and shape and the same length and size as a 'normal' crank - with just the chainring different, how can this improve the hip extension, or make it 'easier' - Will it not also make it harder at another point in the stroke. You might be stronger at that point, but it's still harder?
Posted: 03/10/2007 08:52
Thanks for that Paul Will wait for Richards conclusions,but anything that gives my knees a break is worth the cash.
Posted: 04/10/2007 15:49
I used these for a few months as I was having hamstring/knee issues from an injury. For me they seemed to be good for - lower rpm, e.g. climbing .
- Churning bigger gears.
- Comments from your mates that they look stupid
Bad For: - Any type of ride which involved lots of accelerations
- Sprinting - you cant seem get the power down
- High RPM(>110) - I tried a few different settings, didnt seem to be able to get it.
Plus they are flexible... you can feel them flex when sprinting. Oh and there is no real data on how to set them up... apart from "change it a bit to see if its better"...very technical I've gone back to round ones  Dura Ace... Much better.
Posted: 04/10/2007 17:01
Did your hamstring/knee issue clear up. As Marianne Vos could probably outsprint and out ride most folk (male and female)and she uses Q's for road and Cyclo-cross she seems very happy with them. Not really noticed them flexing when sprinting but at 57yrs I rarely sprint much faster than 65kph! I find no problems riding at high rpm and having them set for, easier when climbing out of the saddle, (small ring) and easier when seated, (large ring) makes an incredible difference. This probably depends on how long you have been riding Q's as everyone has to take time to adapt, this can take longer for certain types of rider, usually pro's or high mileage racers who have pedalled 'full circles' for year's. Whatever anyone thinks, the cost of trying them to gain significant improvements in comfort, recovery, speed and knee protection is pretty cheap when you look at all the expensive carbon components on the market which may save a few ounces but will hardly improve your overall riding speed.
Posted: 04/10/2007 19:17
Did your hamstring/knee issue clear up. As Marianne Vos could probably outsprint and out ride most folk (male and female)and she uses Q's for road and Cyclo-cross she seems very happy with them. Not really noticed them flexing when sprinting but at 57yrs I rarely sprint much faster than 65kph! I find no problems riding at high rpm and having them set for, easier when climbing out of the saddle, (small ring) and easier when seated, (large ring) makes an incredible difference. This probably depends on how long you have been riding Q's as everyone has to take time to adapt, this can take longer for certain types of rider, usually pro's or high mileage racers who have pedalled 'full circles' for year's. Whatever anyone thinks, the cost of trying them to gain significant improvements in comfort, recovery, speed and knee protection is pretty cheap when you look at all the expensive carbon components on the market which may save a few ounces but will hardly improve your overall riding speed. Tom Boonen doesn't use Q-Rings and he could probably outsprint faster than the people on here. What shall I do? I'm a bit confused.
Posted: 04/10/2007 21:02
"but at 57yrs I rarely sprint much faster than 65kph! " Er... 65k is still pretty quick! For me, helped with the hamstring issues, but I was doing a lot of other stuff too, like stretching, massage etc. I went for a ride last night, with my round rings back on, only took 30 mins to get back into it ;o) Maybe its just because ive been riding round for so long that I cant take advantage of the oval... When im sprinting it always felt like the bottom of the power stoke was too short... I think working on technique with round rings is better than trying to go for some cheap(expensive!) fix. Wonder why the track guys dont use oval ... Or the Pros... Boonen would probably bend them back round again ;o)
Posted: 05/10/2007 09:36
A few pro's do use them as do the World triathlon champ, the Spanish tri squads, David Cañada and quite a few others, Bobby Jullich was riding oval rings in tt's but not Q's. I think it was biopace so he wouldn't have known better. Basically the pro's don't ride them because they spend so long riding, doing full circle pedalling that they worry about adapting plus Campag and Shimano wouldn't like it. Re the comment earlier about 'technical advice' if there was a load of scientific data I think it would be seen as hype. The instructions are perfect, everyone is different so you start with the rings in neutral setting and once you are used to them you can then experiment. You make the choice based on your own tests. Still not sure about the bending when sprinting. If I rode a lot of crits with dead turns I would probably set the rings for easier when out of saddle as you are more likely to be out of the saddle from a corner than seated. Re fixed wheel/track men. Probably the fixed wheel momentum overcomes the deadspot so oval wouldn't be needed. For track I think the better solution would be a Rotor system, certainly worth thinking about for pursuiting and a friend who won the Race Across America a few year's ago had been planning to attack the World Hour record using a Rotor system. Q-Rings weren't 'invented' then so maybe he would use them now. As Q-Rings cost less than a 100quid I think they are well worth experimenting with and I bet that if a pro team did start using them it wouldn't be long before everyone else followed. If you want to try them and fancy a week training in Spain I have 3 bikes available and some fantastic routes. Adios
Posted: 05/10/2007 19:37
Actually, I'm going to start using these. Some wafty cranks on eBay...
Posted: 05/10/2007 21:41
OK Adam, Whats the advantage of these and are they worth the price????
Posted: 06/10/2007 00:19
The eBay questions section has a link to an old ad with the supposed advantages - http://www.classicrendezvous.com/Italy/PMP_crk_ad.htm Complete rubbish of course, Tom describes the real advantage (unless you just like having weird old stuff because it's weird and old, in which case the advantage is it's old and weird).
Posted: 19/10/2007 11:14
I don't see Nicole Cooke laughing at Mariane Vos and there are possibly more World and National champs, (all cycling disciplines) riding and winning on Q's over past 2 year's. I doubt other riders will be laughing, after they manage to sign on, when they realise the Q Ring rider had won and finished 15min in front of them. It is ok to laugh about improved old ideas but if they work what's the problem. Adios. PS, The note about are they worth the price, they cost less than 100quid and when you look at the cost of some bikes being ridden by folk struggling to beat the hour for a 25 it hardly seems worth worrying about.
Posted: 04/11/2007 09:35
It isn't a case of not getting it, if technology is around and you form an opinion without trying it for yourself how can you comment. Take it you still use toe clips and straps. I know the Q's work, you recover quicker and can ride faster for the same effort, ok if you are a top rider then life can be easier no matter what you ride but for a rider looking to improve overall performance the Q,s make a better investment than fitting a set of carbon handlebars in order to save a few grams. For a few pro's who need to gain a few seconds in a time trial they would make a big difference but maybe campag and shimano wouldn't appreciate this. It would be interesting to see Q's combined with an SRM unit. Adios
Posted: 05/11/2007 09:45
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