Round chainring Vs oval chainrings
#3
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Join Date: Jan 2009
Location: Colorado Springs, CO
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Bikes: 2015 Charge Plug, 2007 Dahon Boardwalk, 1997 Nishiki Blazer, 1984 Nishiki International, 2006 Felt F65, 1989 Dahon Getaway V
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My 1984 Nishiki International Ole came with oval chainrings upfront (biopace?) I swapped out the smaller one for an even smaller one to help with the hills here in Colorado. To tell you the honest truth I don't feel any difference between the oval and round ring. I mostly commute and my main ride (75-80%) has round rings. My winter bike has round rings. Again, I jump on the Old bike and I don't feel any difference.
Granted I am riding mostly 6- to 7 tenths and don't usually ride flat out, but even when I do, I don't feel a difference. That's not to say there isn't one, but I don't feel it.
I don't have a good photo of the gears handy, and it's dark out, but I looked online and this gear represents the "ovalness" of my big chainring. (It is not my chainring)
From the other images I saw, this is pretty mild. So perhaps a more aggressive oval is more noticable.
Granted I am riding mostly 6- to 7 tenths and don't usually ride flat out, but even when I do, I don't feel a difference. That's not to say there isn't one, but I don't feel it.
I don't have a good photo of the gears handy, and it's dark out, but I looked online and this gear represents the "ovalness" of my big chainring. (It is not my chainring)
From the other images I saw, this is pretty mild. So perhaps a more aggressive oval is more noticable.
#4
Senior Member
I use a Shimano Sante Biopace asymmetrical crankset. I don't have anyway to test it against a round one, but I haven't noticed it being a difference for me yet.
Here is an interesting video I watched about how the orientation of the asymmetrical chainrings can be important:
youtube.com/watch?v=A557LYuFkSM
Here is an interesting video I watched about how the orientation of the asymmetrical chainrings can be important:
youtube.com/watch?v=A557LYuFkSM
#7
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Location: Austin
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I like the Rotor Q-Rings (regular, I've never tried the QXL), but went back to round because of better shifting. The ovals ones felt smoother to me, but there was no performance difference that I could discern.
#8
I used Osymetric for a few months, and really liked them. The only problem I had was that they creaked under power. No matter what I tried, I couldn't get them to stop ticking under heavy power.
#10
Senior Member
There was also a short-lived Shimano variant called "Bee O Pace". The theory was that the bees would motivate the rider to pedal harder and faster, in order to get to their destination quicker and avoid being stung.
#13
Full Member
I had a mid eighties Trek with an oval crank, a triple upfront. I liked it, but as I aged the frame became too long for me. It always had shifting issues. Best part was that it was a great crank to stand up on. I could stand forever on that thing and not slow down. Can't do that as much on a standard crank, turns out I'm faster seated now.
#16
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I currently have Q-Rings on my road bike and I like them a lot. My cross bike has Absolute Black, which is a more pronounced oval, similar to QXL. Personal preference, I like the Q-Rings better for 39t-53t, but the Ab-Black for smaller rings (36t and 34t).
The current ovalized rings should not be confused with Shimano's Bio-Pace rings as the current crop of rings have the larger circumference in a different position relative to the crank. The way the current generation does it is to make it easier to bring the petal around over the 12 O'clock position and back to where you can apply power. Bio-Pace put the larger section where it actually made it harder to come over the top. For me personally, I notice the difference most when spinning in a high cadence up hills and hard seated efforts on the flats. Climbing out of the saddle and sprints, I really can't tell the difference. Similarly, just cruising along at medium power/cadence, not much difference.
As some have said, they can cause problems shifting and you really need to have your front derailleur setup about perfect to avoid this, but once you get everything properly adjusted, it's not really a cause for concern.
The current ovalized rings should not be confused with Shimano's Bio-Pace rings as the current crop of rings have the larger circumference in a different position relative to the crank. The way the current generation does it is to make it easier to bring the petal around over the 12 O'clock position and back to where you can apply power. Bio-Pace put the larger section where it actually made it harder to come over the top. For me personally, I notice the difference most when spinning in a high cadence up hills and hard seated efforts on the flats. Climbing out of the saddle and sprints, I really can't tell the difference. Similarly, just cruising along at medium power/cadence, not much difference.
As some have said, they can cause problems shifting and you really need to have your front derailleur setup about perfect to avoid this, but once you get everything properly adjusted, it's not really a cause for concern.
Last edited by pesty; 08-27-18 at 09:59 AM.
#17
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I rode bio-pace chain rings for the past 20 years or so. They were a little worn so I replaced them a couple of months ago with round rings. The shifting is quicker and snappier than it ever was (friction shift) and I go faster with less effort. I'd say don't waste your hard-earned dollars on oval chain rings.
Jon
Jon
#18
Blast from the Past
I know several riders who have been on Q-Rings for a very long time. One a really good road sprinter with several State Crit championships to his credit. I've given them a shot on a couple of occasions. Most recently a 6 week trial on my TT bike, with several changes in OCP. The oval shape was not noticeable after the first half hour or so, no negative impact on my pedal stroke. I felt that standing was a little easier. I did not see a performance gain based on Power or Time. I didn't have quite as much feel to my pedal stroke when tired/struggling.
In summary I did not see any objective change in my numbers, felt some subjective differences, but none were an advantage. I went back to round.
In summary I did not see any objective change in my numbers, felt some subjective differences, but none were an advantage. I went back to round.
#19
Senior Member
#20
Virgo
I had a bike with the Sugino Cycloid oval rings, I didn't notice any difference and also didn't have any front shifting issues. Must have been lucky.
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