Oval vs Round Single Ring Differences

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  • Oval vs Round Single Ring Differences
  • skybluestu
    Member

    1. Can you get away with another 2 teeth if you go oval over a normal narrow wide ring?
    2. Didn’t oval get tried and scrapped with biopace due to knee problems?!

    whitestone
    Member

    1. Sounds like you are running a 30T so might not be able to fit a 30T oval, yes? I went from 30T round to 32T oval because of that but you can now get a 30T oval to fit 104BCD cranks – it’ll cost though! Some reckon that it’s about 1T difference in effort rather than 2.

    2. Biopace put the long axis in the wrong place (apparently).

    I noticed the oval ring for all of thirty seconds when I fitted it. After that it’s just riding only smoother pedalling.

    mark_rich
    Member

    I wouldn’t go bigger, a 32 oval is equivalent to a 34 at widest point, I went from 34 round to 32 oval and could barely notice any difference, I was hoping to gain a lower gear (which I have but it is offset by it been oval I think)
    If I’d have gone 34 to 36 oval it would have killed me !
    I would recommend oval though as it seems to smooth out my climbing.
    Also had a bad knee which I barely notice now.
    Just built a new bike with a round ring so I’ll see if I notice the difference.

    Premier Icon takisawa2
    Subscriber

    I’m totally convinced for singlespeed, & wouldn’t buy another round ring for the SS. I went up 1 tooth without noticing.

    Not sure what benefits it brings to geared.

    Premier Icon nickc
    Subscriber

    my oval ring is the same as my round was (32T, just seemed less confusing)

    my knees are good.

    skybluestu
    Member

    Currently have 34t round which I think is going to be too much for serious climbing with a 11-42 so was thinking o of 32t rounds but just wondering ifI should consider oval. Interesting opinions. Might give a 32t oval a try and see how it feels.

    ahwiles
    Member

    As above, biopace put the long-axis of the oval 90 degrees out, relative to other oval rings. It seems most people who expressed a preference didn’t like biopace much, and that kinda dented the reputation of oval rings for about 25 years. As a geek, it’s quite interesting why bipoace wasn’t *completely* wrong, but that can wait till morning…

    Premier Icon dawson
    Subscriber

    @Takisawa – what brand is your oval, odd number Ss chainring?

    Premier Icon WildHunter2009
    Subscriber

    Moved from a 32 round to a 32 oval on my singlespeed and to be honest didn’t notice any different. It maybe felt a bit weird standing up and stomping but otherwise. Its now a bodged 10 speed and again I cannot tell, although I suspect the narrow wide tooth profile is the reason I have not lost the chain once.

    qwerty
    Member

    I think it assists ever so slightly on really steep climbs, helps you spin the chain ring round under slow high torque efforts, otherwise not really noticed.

    ahwiles
    Member

    right, i’m back.

    re biopace not being completely wrong:

    riding along at a constant speed means that the chain will be moving at a constant speed. Using round rings means that your feet will also move around their circles at a constant speed. The idea of biopace is that moving your feet at a constant speed is actually a bit tricky (especially at the top and bottom), and the alignment of the biopace oval means you can keep a constant chain-speed, with naturally varying foot-speed.

    like i said, it’s sort of interesting, in a geeky way, but the obvious outcome of biopace was that it made pedalling harder when your legs were at their weakest (at the top of the stroke, when your knees are most bent).

    You could possibly say that biopace might suit a time-trialler, hoping to maintain a constant speed. and the ‘traditional’ oval rings we’re seeing again might suit a mountainbiker, whose speed up a tricky hill definitely isn’t constant…

    maybe…

    i suspect there is at least one phd-in-waiting on the aerodynamic benefits of biopace, as a reduction in foot-speed would mean a reduction in drag…

    Premier Icon epicyclo
    Subscriber

    Any stainless steel oval rings?

    qwerty
    Member

    i suspect there is at least one phd-in-waiting on the aerodynamic benefits of biopace

    aphex_2k
    Member

    Just gone from 32 n/w to 34t oval. Can definitely feel it but not ridden it many k’s yet

    Went from 32t round to 32t oval. Noticed a positive difference initially, now it feels normal.

    qwerty
    Member

    ^ that chain links not N/W.

    ahwiles
    Member

    qwerty – Member
    Que?

    Cyclists feet are stuck out to the sides, in relatively clean air.

    At the top of the pedal stroke, a cyclists feet are travelling through the air twice as fast as everything else. Drag force is based on speed-squared, so if you slow down a bit, you reduce the drag-force by a lot. When it comes to aerodynamics, feet are important.

    If biopace slows down your feet by a bit, it will reduce their drag by a lot.

    maybe…

    (chuck in a bit of background reading, some CFD work, and maybe a wind tunnel test, there’s your/my phd/nobel prize/etc.)

    emac65
    Member

    Got one bike with an oval ring & several with standard round ones. I can’t tell the difference TBH & often forget which bike has the oval on it…I won’t be buying another one that’s for sure

    bmbird4
    Member

    I have Ovals “elliptical” chainrings on all my bikes. Pedal stroke feels a lot smoother, how you say? I don’t really know but I’ve read studies that say your legs naturally dont spin in a circular motion, they spin in a squared off motion, and an oval helps with this and makes your pedal feel more “natural”; in which it does feel better. As far as more traction? I would say yes because your power stroke is “stronger/slower” so your going to be less likely to spin out but also recover more quickly since your upstroke feels easier/faster. The rule of thumb is don’t get the same size oval as your round chainring because it feels 2 teeth bigger, which is true. It’ll wear you out if you go big. They have the “timing” of the oval correct on these newer chainrings (wolftooth & absoluteBlack is what i have experience with). Try one, i doubt youll take it off.

    slimjim78
    Member

    Went from round 32 to Absolute Black Oval 30.
    Struggled to tell a difference at first, riding uphill feels nicely smoothed out, can feel a slight reduction in tyre bob when spinning (fat bike).
    I like it.

    Had a 32T Oval on my Alfined 29er and I could tell the difference switching between that and my road bike, so much so I want Ovals for that, I’m missing the oval on my new ride but not sure I have the clearance for an oval on it, it’s very tight with a round 30T.
    I’m keeping my eye out for a 38T or 40T oval for my new build but don’t really want to switch cranks for 110bcd….

    Cheers, Steve

    Premier Icon chris2407
    Subscriber

    I really rate my oval chainring (AbsoluteBlack 32T) on steeper terrain the traction over wet roots just seems slightly better.

    Any stainless steel oval rings?

    If you run a Cinch crank then Wolftooth do one, for their Camo spider.

    CAMO Stainless Steel Elliptical Chainring

    I’m waiting for SS to make some 5-bolt 110BCD 40T ovals for my commuter.

    So far I’ve only seen Wolftooth do these, and they are pricey.

    I’ve gone from 32t round to 34t oval on my ss and my geared. Very noticeable on ss. Offers bags if traction strangely enough for out the saddle efforts. It makes the bike feel like a big step machine. Been running them about 18 months.

    Less difference on the geared. Not sure why. Might be something to do with the ss being rigid. Just fitted a 38t oval on the cx. Felt good on the first ride out. Somewhere between the other two in terms of noticeability.

    In a nutshell – i won’t be going back to round if the prices are comparable.

    Premier Icon cynic-al
    Subscriber

    I’d these rings genuinely got you an increased power output or whatever it would have been tested and evidence used to sell them.

    Has anyone seen such tests?

    Otherwise it’s just subjective at best and just snake oil

    ahwiles
    Member

    Snake oil? Hardly – there’s some very basic physics at work.

    Rich
    Member

    It would be interesting to see the results of a blind test.

    Premier Icon Northwind
    Subscriber

    They definitely do make a difference- it’s really obvious on my fatbike, pedalling the oval is smoother and less blobby. Is it faster? Easier? No clue, but it feels faster and that’s worth it.

    I can’t tell any difference on the big bike but tbh, I’m not sure how I would, without Science, I don’t believe the human body and brain is a suitable tool to measure that… I just replaced it with a round one and tbh I was barely aware of any difference on ride 1, and now it’s forgotten. I’m pretty sure it does no harm, though.

    It would be interesting to see the results of a blind test.

    You’d need a rider who couldn’t feel the difference between the two…

    I suspect you mean a controlled experiment, with matched power outputs.

    The subjective effects of ovals are subtle IME. More obvious on a rigid/hardtail setup than the fullsusser for me. I like them.

    Premier Icon lovewookie
    Subscriber

    I was runing oval on my hack bike about a year ago, a 36t and moved to a 34t round after about 10 months use as it was knackered after that (I happened to have a 34t round in the shed).

    I was quite surprised really. my flat to hilly 20 odd mile long way home with the 36t oval felt great, but my legs really ached afterwards, like I was pushing big gears. However, riding on the hills, it felt a lot easier than I thought it would.

    move to the 34T round and it felt the same on the hills, though my legs were less achy.

    Not particularly scientific, but non biased too as i happened to have the kit hanging around, rather than buying oval specifically to see if it worked.

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