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[Closed] Oval Chainrings for MTB

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[#7532608]

Specifically for 1 x 11, I'm intrigued whether the following statements from the Absolute Black site; I appreciate they are marketing, but are they true:

a) With oval rings rear tire traction improves greatly on loose and slippery terrain

b) This results in higher average speed.

c) utilize more muscle groups (compared to round one), but each of them to lesser degree. Load from pedaling an oval chainring is spread over greater muscle mass which in effect gives you the feeling of fresher and more relaxed legs.

d) help climb steeper hills more effectively

If yes, I'm inclined to buy one and avoid the XT 34t that comes with the groupset I've bought...?


 
Posted : 22/12/2015 12:46 pm
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Why not just get one and try it? They're only about 30 quid on CRC.

FWIW I like them and for me think the statements above generally apply.


 
Posted : 22/12/2015 12:52 pm
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I'll be sorting a set out for my bike in the spring, not expensive enough to be a concern if they are not all they are cracked up to be. And i need new chainrings anyway.


 
Posted : 22/12/2015 12:53 pm
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Personally I prefer the oval chainrings to round ones on the MTB.

One thing I will say about them is that I didn't get on with the OneKey ones with a fixed position as they just felt 'wrong'
On the other hand I've got a Rotor Q-Ring on the MTB and I found that the ability to switch positions of the oval worked better for me as one suited me better than the other two. Obviously this will vary from person to person.


 
Posted : 22/12/2015 12:58 pm
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With oval rings rear tire traction improves greatly on loose and slippery terrain

Of the three things you've said, I've found this one. In those tricky situations where you need a bit of "hmmmpppff" the oval ring makes it easier.

The other two I've no idea.


 
Posted : 22/12/2015 1:06 pm
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I've been running an oval ring for ~6 months and I like it, I'm not sure if it makes any real difference other than I think it smooths out my stroke. Other factors, weight & illness, have had more of an impact in my case but I ordered an oval ring for my nw build without thinking about it too much so I must like them.


 
Posted : 22/12/2015 1:10 pm
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One thing I will say about them is that I didn't get on with the OneKey ones with a fixed position as they just felt 'wrong'

Is a good point that. Read some where that if you don't get on with a wonky ring then the it's because the wonkiness isn't properly tuned to your pedal stroke (so might be shape or orientation.) Think this is probably true. On the TT bike I run rotor rings and some of the positions definitely work better for me than others.


 
Posted : 22/12/2015 1:12 pm
 gary
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I've had an absolute black ring on my SS for a few months - I like it, seems to "do what it says on the tin" in terms of smoothing out the pedal stroke.

On the SS that seems to equate to not running out of gear quite so soon on the climb but also an ability to spin up to a faster top speed which I wasn't expecting.

I like it enough that I'm quite tempted to get one for my 1x11 bike too, the only thing that's stopping me is the fact the ring on there is barely worn, if I needed a replacement it would be a no brainer.


 
Posted : 22/12/2015 1:17 pm
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Has anyone tried an oval as the middle of a triple? I'd like to test one, don't want to replace all three.


 
Posted : 22/12/2015 1:19 pm
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weirdly, it actually feels like you're pedalling in circles, and a round ring in comparison feels less circular!


 
Posted : 22/12/2015 1:19 pm
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Has anyone tried an oval as the middle of a triple? I'd like to test one, don't want to replace all three.

I suspect doing that would lead to spectacularly bad front shifting .


 
Posted : 22/12/2015 1:24 pm
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Yup,same as nick I noticed more traction (less wheel spin)over steep, tricky climbs when I had an granny oval ring.


 
Posted : 22/12/2015 1:27 pm
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Definitely feels nicer than the round one I've got, smoother more even pedalling. Whether i actually makes a performance improvement I couldn't say but I'd get another for sure.


 
Posted : 22/12/2015 1:47 pm
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Superstar are selling oval rings now


 
Posted : 22/12/2015 2:04 pm
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Souonds positive, thanks chaps.

After promising Mrs K there was nothing more to spend on Bikes at the moment, I now need to spend 10% again of what I've already spent this month.

I think I'll get this one delivered to work...


 
Posted : 22/12/2015 2:23 pm
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I think I'll get this one delivered to work...

Collect+ is the way to go to avoid suspicious looking packages turning up at home 🙂


 
Posted : 22/12/2015 2:25 pm
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So far, so good, running an Absolute Black 30t oval on the 601 (no top guide though).

Got another 32t one ready to try on the hardtail but I've yet to see how it fits with the one-up topguide, which I wouldn't want to loose. (effectively it'll have to accomodate the dia of a 30t in one position and a 34t in another)


 
Posted : 22/12/2015 4:45 pm
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effectively it'll have to accomodate the dia of a 30t in one position and a 34t in another

sounds a lot but isn't - I reckoned about a 5mm difference in radius on my 34T oval (so 32-36 effective diff)


 
Posted : 22/12/2015 4:50 pm
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There was a PSA on here for the works components ones, if that helps you.


 
Posted : 22/12/2015 4:53 pm
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Laying it over a std 30t ring, it looked more like +/- 5 mm radius but it wasn't a very scientific test.
I'll try it at next drivetrain change anyway.
I do quite like the feel of the pedalstroke with oval rings.

The only other very slight drawback I can see is that the chainring diameter will be at it's greatest when feet are fore/aft for descending/techy stuff, reducing ground clearance over rocks.


 
Posted : 22/12/2015 5:01 pm
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I have a 30t Absolute Black on my Bronson, I'd say (a) and (d) are true.

It feels like you have more torque, it's always ready when you put your foot down to accelerate on a technical climb.

It's not a night and day difference but I definitely won't be going back to round after trying oval as there's no disadvantages (except maybe cost?).


 
Posted : 22/12/2015 5:04 pm
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I should have a black 32T spare soon- going to a 28T cinch on the fatty.

I'm not totally a convert tbh. On the fatbike it makes a real noticable difference for me, basically because of all the sitting down and pedalling a fairly low gear, that gets pretty boingy with a round ring and the oval smooths that out. Big fan.

On the hardtail, I can't really tell. Maybe it makes a difference, I'm totally comfortable with the idea that maybe it's really positive but I just can't tell. Or maybe it's not.

On the full suss I didn't really like it, it's a very anti-squatty bike and it all seemed to come together to feel a bit odd and overcomplicated. Not terrible, just... kind of barely noticably different and distracting, like a sound you can barely hear


 
Posted : 22/12/2015 5:21 pm
 DanW
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I think a lot depends on your pedaling technique.

They didn't do a lot for me and I can't notice or measure and difference between the two.

They haven't done any harm either so give them a go.

c) utilize more muscle groups (compared to round one), but each of them to lesser degree. Load from pedaling an oval chainring is spread over greater muscle mass which in effect gives you the feeling of fresher and more relaxed legs.

As a Biomechanist I would to know where Marcin got that information from 😉 😆 All of the statements are anecdotally described by some people but are far from proven facts AFAIK... AKA marketing


 
Posted : 22/12/2015 5:27 pm
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They're giving you a variable gear ratio that is a better match to your variable power output during the pedal stroke. I think that's the theory anyway, I've not tried one yet.

The muscle groups thing; do you use muscles differently in different gears? I mean if you compare pedalling a hard gear to an easy gear is the muscle loading different? If so, I can see where that statement might come from.

It should be more efficient, but whether that's because you're spreading the load better I've no idea.


 
Posted : 22/12/2015 7:34 pm
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Well, I've just ordered a 34t Abs Black XT M8000 for my 1 x 11 setup. Should be interesting going from standard 2 x 10 SLX to all that change!


 
Posted : 22/12/2015 7:45 pm
 DanW
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Rotor have invested a lot of time and effort to try and quantify oval rings in terms of muscle recruitment and various physiological measures and as far as I am aware their conclusion is "it doesn't make anything worse"


 
Posted : 22/12/2015 7:52 pm
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Kryton you did get the M8000 specific ring with the 96mm BCD and uneven bolt pattern . I got it wrong first time .


 
Posted : 22/12/2015 7:54 pm
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I'm not totally a convert tbh. On the fatbike it makes a real noticable difference for me, basically because of all the sitting down and pedalling a fairly low gear, that gets pretty boingy with a round ring and the oval smooths that out. Big fan.

What frame is your fatbike? I'm running a 32T round ring on my OO Fatty, but this looks to be on the limit before the ring starts hitting the frame. I have a feeling that the oval ring would be too much.


 
Posted : 22/12/2015 8:41 pm
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I had a 1x10 with a 34t on my OOF and it worked but I wasn't happy with it clearance wise.


 
Posted : 22/12/2015 8:56 pm
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Hypnotoad- mine's a Dune, it was built for 22/36 so it's happy with single ring in the middle.


 
Posted : 22/12/2015 8:58 pm
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@Neil - I think so, this one:

http://www.chainreactioncycles.com/black-by-absoluteblack-narrow-wide-oval-xt-m8000-chainring/rp-prod139806

Edit : Do I need new chainring bolts?


 
Posted : 22/12/2015 9:18 pm
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I've used AB oval rings for quite a few 000 Kms this year.

Id agree that they give better traction on loose climbs. Maybe by smoothing out the power band?

It's possible that the claimed reduction in fatigue is because it does feel (to me) that that there's a greater degree of rotation that you can push through easier, if that makes sense, than with a round ring. With a round ring it feels like each leg is pushing hard between 2-4 o'clock whereas the ovals are more like 1-5 o'clock.

Never looked if they are faster on specific climbs. But they feel 'right' (after the first 10 minutes!) they feel rounder. I would guess they are possibly quicker up a loose or techy climb. And therefore more effective.

They won't let you effortlessly float up climbs you could never clean before. They won't let you climb in one higher gear than before. But I think they're a bit better and I would rather use them than a round 'un, even though they are more costly.


 
Posted : 22/12/2015 9:57 pm
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Does anyone use oval rings on a double chainset for MTB? Do they shift ok?

Having tried one on a singlespeed a while back I like the idea, but I'm not interested in going single ring on my geared bike.


 
Posted : 23/12/2015 9:58 am
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Northwind, I'll take that 32T off you when you come to get rid, email in profile whenever you decide to ditch.

Greg.


 
Posted : 23/12/2015 10:03 am
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According to Geoff Apps:

https://crosscountrycycle.wordpress.com/2014/10/08/out-of-round/


 
Posted : 23/12/2015 11:26 am
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Yes, I've used a 28/40 QRing set up on my XC bike for marathon racing. Shifting is a bit slower, but I find the benefits outweigh the disadvantages. Generally stuck it in one gear and only changed for big climbs and fast fireroad descents.


 
Posted : 23/12/2015 11:45 am
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Yes, I've used a 28/40 QRing set up on my XC bike for marathon racing.

Thanks - that's the sort of riding I've got in mind too.

Which brand of rings do you use?


 
Posted : 23/12/2015 12:07 pm
 DanW
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^ QRings are made by Rotor. Not many oval options for MTB doubles out there


 
Posted : 23/12/2015 12:39 pm
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Oh yes - failed to read that properly!


 
Posted : 23/12/2015 12:42 pm
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Anyone on here tried a properly wonky ring like the Osymetirc on their mtb?


 
Posted : 23/12/2015 1:08 pm
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[url] http://www.aribike.it/eng/mtb%20double%20eng/267_double_shimano_xtr_m9000_bcd96-64.htm [/url] there are these for new Shimano


 
Posted : 23/12/2015 1:28 pm
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If all they do is get your legs back to the strong part of your stroke quicker that's good enough for me.

I really like my Works Components version, even if the hump looks like it's in the wrong place.


 
Posted : 23/12/2015 2:29 pm
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I got an oval n/w ring from Superstar for a smidge over £20 in their sale, will fit it next year at some point.


 
Posted : 23/12/2015 4:39 pm
 poah
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got a works componets 32T oval on my dartmoor hornet but not tried it off road yet.


 
Posted : 23/12/2015 5:29 pm