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Elliptical/Oval Chainrings

BhimaBhima Posts: 2,145
edited October 2010 in Training, fitness and health
Anyone used them?

If I understand things correctly, they're supposed to make it easier to get power down though the whole rotation... On circular ones, I have spent months training to get a perfect circular pedal rotation, so will these give me no advantage, as i'm used to doing circles now?

If the (claimed) increase in power output is to be believed, why don't all the pros use them?

How will they affect high cadence work? Will they make it harder to spin a tiny gear really really fast?

My current chainrings are on the way out so i'm considering giving these a go.

EDIT: Can't find em anywhere! Who sells them?
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Posts

  • fnegronifnegroni Posts: 794
    I used to have them on my Specialized Hardrock mtb about 23 years ago.

    Back then I thought they only made a difference when I was pushing a too-big a gear.

    But I also didn't find them hindering in any way.

    Apparently the Garmin team had them this year for the Giro TTT.
  • woody-somwoody-som Posts: 1,001
    i currently have on the best bike rotor Q rings, and not that i noticed much difference, but was finding I could ride in a higher gear without an increase in effort.
  • mclarentmclarent Posts: 784
    Funnily enough, I was looking at one of these in a shop today, chap described the efficiency gain as something equivalent to having an extra gear at the top end and at the bottom end. Haven't tried it yet though - maybe when I upgrade my bike...
    "And the Lord said unto Cain, 'where is Abel thy brother?' And he said, 'I know not: I dropped him on the climb up to the motorway bridge'."
    - eccolafilosofiadelpedale
  • mclarentmclarent Posts: 784
    "And the Lord said unto Cain, 'where is Abel thy brother?' And he said, 'I know not: I dropped him on the climb up to the motorway bridge'."
    - eccolafilosofiadelpedale
  • mclarentmclarent Posts: 784
    "And the Lord said unto Cain, 'where is Abel thy brother?' And he said, 'I know not: I dropped him on the climb up to the motorway bridge'."
    - eccolafilosofiadelpedale
  • cougiecougie Posts: 22,512
    I thought the shimano biopace rings were set the other way round to these Q rings ?

    I rode Biopace back in the day - couldnt honestly say that I noticed any difference though.
  • AllTheGearAllTheGear Posts: 248
    I read that the Shimano ones got less elliptical each year until they were round again. And that they knackered your knees....

    I can't see how they would make much difference at all, looks like a marketing ploy to me!

    Where do you get them from then? :wink:
    ... and no idea ...

    FCN: 3
  • jkmr1jkmr1 Posts: 6
    I am a 43yo who took up cycling two years ago. I have been using these for the last six months now. Was initially sceptical but after reading many reviews decided to give them a go. First thing i noticed was that they improved my pedalling action. It became far smoother and less chopy. It was much easier to 'pedal in circles'. I believe that this is due to the the decrease in effective chain ring size at the dead spot. This allows you to pass through this area with less effort. In the area of the pedal stroke that allows the greatest force to be generated, the effective size increases. This enables the pushing of a taller gear and hence greater speeds. The other thing that I noticed imediatly, was far less knee discomfort.
    The best thing however was the differance they made to my times over certain routes. I had been trying for many months to post a sub 2 hour time over a 60km route that encompases 1000mtr of climbing. Prior to fitting these rings, the best time i had posted was 2:02:00. The very first ride with these in place saw me post a time of 1:58:00. best ever to date is 1:54:00. In my opinion do they make a differance? certainly! Would I recomend them? You bet ya! Would I go back to round chain rings? No chance.

    Some reviews here: http://www.roadbikereview.com/cat/drive ... 85crx.aspx

    www.mtbr.com/cat/drivetrain/chainring/r ... 12crx.aspx - 144k -


    www.croydoncycleworks.com/shop/product_ ... ts_id=1088 - 34k -

    If you are looking to replace your chainrings, Can't hurt to give them a go.
  • Alex_Simmons/RSTAlex_Simmons/RST Posts: 4,161
    The weight of evidence would suggest there is no advantage to be gained through the use of a non-circular chainring over circular chainring. Of the following, all but the last one found no performance advantages:

    http://www.ncbi.nlm.nih.gov/pubmed/1435158?
    http://www.ncbi.nlm.nih.gov/pubmed/16846753?
    http://www.ncbi.nlm.nih.gov/pubmed/17369796?
    http://www.ncbi.nlm.nih.gov/pubmed/11404667?
    http://www.ncbi.nlm.nih.gov/pubmed/1601563?
    http://www.ncbi.nlm.nih.gov/pubmed/12955523?
    although latter one appears to use variable length cranks rather than non circular chainrings.
  • woody-somwoody-som Posts: 1,001
    JKMR1, you have put the point across perfectly, thats exactly what I have found, but funnily you don't really feel the fact that they aren't round. I first saw them a few years ago at Ironman UK on one of the pros bike. I spoke to him afterwards, and he let me have a go, I wasn't convinced, but he reckoned the benefits were enough to have them, and I gave it a go, not regretting it one bit.
    Also Marian Vos won the world championships using them.
  • InfamousInfamous Posts: 1,158
    How can they possibly be more efficient? all they do is change the gear ratio over the pedal stroke.

    Gimmick imo.
  • liversedgeliversedge Posts: 1,002
    I do wonder whether they reduce fatigue in the weaker muscles "used over the top" and "back through the bottom" of the pedal stoke and thus a rider's ability to sustain power levels for longer.

    None of the research cited by Alex seemed to look at long workout durations where reduced fatigue could deliver a significant benefit.

    I'd quite like to give them a go, you never know. Of course, one should never discount the placebo effect. And the 'i parted with wads of cash so i won't admit they're pointless' effect too!!! :lol:
    --
    Obsessed is just a word elephants use to describe the dedicated. http://markliversedge.blogspot.com
  • Alex_Simmons/RSTAlex_Simmons/RST Posts: 4,161
    Despite the research, I am thinking of trialling them as well at some stage and have a buddy with a set he is prepared to lend me when I am ready.

    The issue for me is a little different as I effectvely have one cleat placed under my "ankle" and as such when my knee is at TDC, the pedal is not nearly as far forward as it would be with a traditional cleat placement. In essence it means the firing sequence for each leg is not quite 180 degrees but slightly out of phase. So I am wondering if they will make any difference for me.

    I suspect not but am willing to test them out and at least I'll have power data to make a sensible n=1 personal judgement and can ride two bikes with same set up, one with circular, one non-circular rings.

    If ever I get round to it, I'll report my findings, most likely via a blog update.
  • PokerfacePokerface Posts: 8,640
    I'm with you Alex - my pedallng dead spot is over emphasized and was hoping these chainrings might help. As we discussed before - Jody Cundy uses something similar and it has helped him greatly.
  • liversedgeliversedge Posts: 1,002
    I found this post about elliptical rings on SRM cranks from someone from q-rotor cranks.

    "When you attach Q-Rings to the SRM crankset, the speed varies twice per
    revolution, but the SRM system doesn’t know that, so there is a small
    error in the power displayed.

    Normally you will find that for flat pedalling and the same speed and
    real power, SRM displays slightly more wattage with Q-Rings than for
    round rings. The difference can be ~1% (more error when using OCP#1,
    less when using #5 for the OCP)."
    --
    Obsessed is just a word elephants use to describe the dedicated. http://markliversedge.blogspot.com
  • Alex_Simmons/RSTAlex_Simmons/RST Posts: 4,161
    Yeah - I am aware of the issue with SRM, it's been debated a lot on other forums over the years. And I'm not so sure SRM has it right either but I can't recall the outcome of the analysis done by all those very clever people. I can look it up if ever I need to know.

    I'll be making comparisons using my Powertap meters anyway.
  • BhimaBhima Posts: 2,145
    Right.

    A friend has some on his MTB so i'm going to give them a go in a few weeks time when he's back off holiday.

    Even though the more I look into it, the more people say they don't give you any improvement, I think that I need to try them myself. Even if there's no power improvement, the lack of "dead spot" might help on the hills...

    £100 though...! :shock: Why are they so expensive? And who stocks them???

    Would I just get the same number of teeth as my circular rings? If I get one which is 50t, it claims to feel like a 52t when on the downstroke and 48t when at the "dead spot"... Should I get a smaller one to compensate and make it feel like I'm still spinning my 50t when on the downstroke?
  • jkmr1jkmr1 Posts: 6
    No. I think you would still get a 50 tooth ring. From my experiance, you don't notice the increase at all due to the fact that it is positioned in the area of max power production. Also, in my opinion, they have assisted in my maintenance of a high cadence as apposed to any negative influence. I think the theory is that they allow (for the same effort) the pushing of a higher gear. Hence, a compact 50/34 becomes a 52/36 but it dosn't feel like it. So theoreticaly you go faster. Also 100 quid is cheap compared to the $300 they are here. I think next time I need to replace mine I'll get them from the UK and get them shipped. That is if anyone comes up with somewhere you can get them there!
    Interested to know how your trial goes. Although I think it would be difficult to gain a true feel for the differance given the fact that they are on a MTB.
  • meenaghmanmeenaghman Posts: 345
    I've been running Q Rings on a campag compact ultratorque chainset for the last couple of months.
    A few observations
    1. The Q Rings are thicker (plate wise) than the ultra torque rings and I seem to be having some issues with shifting / trimming my front derailleur.. It could be just my set up, old ergo levers and newer Qshift front derailleur.
    2. for Campag Compact they only make 36/50 so I had to go two teeth bigger on the small ring.. replacing 34/50 setup.
    Despite the 2 teeth difference I seem to be able to climb most of my hills (some round here are 15 percent with ramps of 18-20) in the same way as before. I've noticed that it seems easier to spin the gear up to speed.. eg catching paceline out of corners..
    I have noticed a slightly smoother style.. I'm not a smooth pedaller by any means though..
    I reckon if like me and you pedal a bit in squares or ride a bike like a cowboy.. ie jig about a bit on the saddle, then these are beneficial. I reckon if you're a smooth pedaller anyway that you wont see much difference. I found when I take another bike out with round rings that my pedalling action has got a bit smoother.
    I would like to try the actual proper rotor chainset with the cam.. I believe it will give more mechanical advantage than these rings but its quite expensive and heavy.
  • eheh Posts: 4,854
    Surely if these things worked we'd have spotted it by now, ellipical chainrings are hardly new, Sheldon Brown notes they've been in existence since almost as soon as bikes with chains were invented.
  • PokerfacePokerface Posts: 8,640
    eh wrote:
    Surely if these things worked we'd have spotted it by now, ellipical chainrings are hardly new, Sheldon Brown notes they've been in existence since almost as soon as bikes with chains were invented.

    And yet - there is now an entire pro team (Cervello) using them! Bradley Wiggins uses an ovalized set up also.

    I'm guessing there isn't a significant advantage to using them, and in many case NO advantage - but for some riders there must be a reason to sue them. Otherwise.....
  • sub55sub55 Posts: 1,025
    constantly reavalueating the situation and altering the perceived parameters accordingly
  • Alex_Simmons/RSTAlex_Simmons/RST Posts: 4,161
    Often Pro riders are using bikes/components/apparel/technology because they are sponsored to do so, not because it is the best thing for them.
  • zammmmozammmmo Posts: 315
    Yes, as regards Cervelo I think the clue is in the team name: Cervelo TEST team.
    Interesting idea though....
  • kozzokozzo Posts: 182
    Front shifting may cause the problems depending on part of oval.
    It demands more attention.
  • AllTheGearAllTheGear Posts: 248
    The reason they are so expensive (£145) is that the pro teams are being paid a heap of cash to use them. If they use an item through choice, they obliterate the brand name or replace it with that of the sponsor for the component.

    However, if they were detrimental in any way then they would not be using them.
    ... and no idea ...

    FCN: 3
  • PokerfacePokerface Posts: 8,640
    Often Pro riders are using bikes/components/apparel/technology because they are sponsored to do so, not because it is the best thing for them.

    Agreed - but GOOD riders will change their equipment to a certain degree, regardless of sponsor, to suit their needs. Wheels, drivetrain, stems, bars, clothing have all been changed and/or re-badged to suit particular riders.

    Somehow I don't think Carlos Sastre would be riding Q-rings (and win the Tour with them) if he wasn't happy about it - especially when he could have used Dura Ace instead.

    Same with Wiggins - he chooses to use eliptical rings. Not because he has to.
  • PokerfacePokerface Posts: 8,640
    And others won using round rings.

    I guess by that logic - everyone should keep using steel framed bikes because more people won on them then carbon fibre ones.
  • Alex_Simmons/RSTAlex_Simmons/RST Posts: 4,161
    I don't consider that a good analogy, since the peleton all moved to lighter, stiffer, more aerodynamic frames at about the same time as the technology became readily available (since there was a performance advantage in doing so).

    Ring choice however has been with us for a long time and yet there has been very little uptake, since there really isn't much in the way of performance advantage.
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