Oval Narrow/Wide - anybody got one?

**epic** · 03-31-2015, 06:38 PM

Looking to finally go single ring on my Intense this spring. I'm thinking of trying a 34T oval narrow/wide. The only one I know of is from Rotor. Anybody tried it? Anybody know of any other options?

**alewi11** · 03-31-2015, 06:52 PM

I just picked up a chinese knockoff from ebay. I haven't tried it yet. $.99 plus $12 for shipping. Figured it was worth a shot.

**jm2e** · 03-31-2015, 08:22 PM

I've been looking at this. Direct mount for X9 GXP crankset.

http://www.amazon.com/B-Labs-Bionico...nring+oval+28t

**jono** · 03-31-2015, 10:29 PM

I have ridden the Rotor briefly and I liked it quite well. Can't compare with the other options, but that one worked nicely, at least for my pedaling stroke. I used it in the middle of the three positions, never tried rotating it.

I have a knee that's driving me to considering shorter crank arms and I might grab one of those instead--or first, at least. They talk it up for high cadence, and it felt fine there, but for me the big plus was very low cadence/high torque, because it noticeably reduced the peak torque required to turn the pedal over at the top of the stroke. Obviously that gets made up 90 degrees later, but I found that part barely noticeable.

**Tyrone Shoelaces** · 04-01-2015, 08:17 AM

Originally Posted by epic

Looking to finally go single ring on my Intense this spring. I'm thinking of trying a 34T oval narrow/wide. The only one I know of is from Rotor. Anybody tried it? Anybody know of any other options?

Yeah currently I have a Rotor CX1 44T ring on my SSCX and a B-Labs 36T Oval N/W on my 1x11 29er race hardtail.

I'm a big fan of both. I tend to notice the effects of the ring mostly when I run them on singlespeeds but that is to be expected I guess.

In my experience Rotor rings tend to wear faster than I would like, but the B-Labs gives me hope that it will last longer. I don't have many miles on it yet, but it at least appears that there is a lot more material in the ring.

The US Distributor for B-Labs is based in the Reno area. I have his email and if you have any questions he is super responsive and ships things quick. PM me if you'd like it.

**xyz** · 04-01-2015, 12:08 PM

I had a Biopace ring in the late 1980's. It was the shit, or just shit, cant really remember.

**bagtagley** · 04-01-2015, 12:18 PM

Originally Posted by xyz

I had a Biopace ring in the late 1980's. It was the shit, or just shit, cant really remember.

Somebody rotated their Biopace rings a couple holes and invented something completely new! Sheldon Brown was a Biopace believer, maybe there's something to it.

**garuda** · 04-01-2015, 01:09 PM

check out Absolute Black rings. Much cheaper than rotor. I haven't used them but generally positive reviews if you're into the oval thing. Lots of interwebs reviews and long mtbr threads on them like this one http://forums.mtbr.com/singlespeed/o...ed-932469.html

**Tyrone Shoelaces** · 04-01-2015, 01:30 PM

Originally Posted by bagtagley

Somebody rotated their Biopace rings a couple holes and invented something completely new!.

Pretty much.

FWIW, when I got my first Rotor oval ring a few years ago, I mounted it backwards. And indeed, it had the opposite effect, and it was terrible. Definitely made things much harder. So then when I swapped back to the correct way, bam....nice.

**evdog** · 04-01-2015, 10:05 PM

Originally Posted by bagtagley

Somebody rotated their Biopace rings a couple holes and invented something completely new! Sheldon Brown was a Biopace believer, maybe there's something to it.

Local guy I know just put the Absolute black ring on his bike. Seems to like it so far. According to their site biopace had the oval shape oriented the wrong way which made it harder to pedal. The AB ring has the narrow part delivering power when you are at the weakest (top) part of the pedal stroke and the widest part delivering power during the most powerful part of the pedal stroke. See "word on Biopace" http://absoluteblack.cc/oval-104bcd-chainring.html. Seems to make sense. I might try one of these next time I need a ring. Not much more than the last ring I bought.

**Damian Sanders** · 06-03-2015, 01:54 PM

I wonder how one of these would work with a shorter crank (165mm or 170mm) for all around trail riding, vs. your standard 175mm?

**Damian Sanders** · 06-04-2015, 07:13 AM

I thought a bit more about this while riding yesterday. I've ridden clipless exclusively (including racing DH) for about 20 years, and have a pretty well refined circular pedal stroke, meaning that I pull back and push forward when the crank is vertical and don't mash in the mid-stroke. I'm also a very good technical climber and have ridden long travel FSR bikes for years, both things that benefit from a consistant stroke. I'm guessing that I would benefit less from these oval rings, but they are used by road riders who have a refined stroke and ride clipless, sooo....?

http://www.roadbikerider.com/cycling...-pedal-strokes

Another way to get feedback is to ride a mountain bike up a steep hill with a loose, gravely surface. If you pedal jerkily, pushing down hard, you'll lose rear-wheel traction. The tire will spin abruptly on the loose gravel, causing you to lose momentum and put a foot down. But if you concentrate on pedaling evenly through the whole 360-degree circle, the rear wheel won't lose traction.

Interestingly, said Broker, among all the riders tested over the years at the U.S. Olympic Training Center in Colorado Springs, mountain bikers had the smoothest pedal stroke, even smoother than pursuit specialists on the track. Off-road legend John Tomac was the smoothest of all.

**jm2e** · 06-04-2015, 08:35 AM

Interesting perspective. I'm going in the opposite direction. I just switched to flats about a month ago because of a year long knee problem. The knee is responding well to the change, but my shins are suffering dearly!
Since I'm still in the tentative stage of the transition, I'm a bit concerned that the oval will fuck things up enough to set me back from the little progress I've made.
With Shimano's new XT 11 speed drivetrain parts coming out soon though, I'm getting ready to drop a few hundo on my drivetrain, so this would be a logical time to go Oval.

**Capatain** · 06-04-2015, 10:11 AM

Getting the wolftooth 32t oval mounted right now. will give feedback after a few rides!

**jono** · 06-04-2015, 10:54 PM

Originally Posted by Damian Sanders

I'm also a very good technical climber and have ridden long travel FSR bikes for years, both things that benefit from a consistant stroke. I'm guessing that I would benefit less from these oval rings, but they are used by road riders who have a refined stroke and ride clipless, sooo....?

http://www.roadbikerider.com/cycling...-pedal-strokes

It's easy to feel yourself pushing fore and aft on the pedals when the crank crosses vertical, but if you quantify that and compare it with the force applied mid-stroke you'll notice that even a comparatively circular pedal stroke goes almost to zero torque at top dead center. It's not at all like turning a crank using your arm/hand. Even with a "circular" stroke you'll still notice and probably benefit.

Trying to avoid full geek mode...the torque vs crank angle is commonly accepted to approach a sine wave whose average is half its peak as a rider gets more efficient. If that's accurate (the research goes back to the 1890's, but one study from Japan seems to have the best evidence for correlating efficiency with sinusoidal torque) then even the optimal pedal stroke for an experienced rider falls very close to zero across top dead center. Mountain bikers have a lot more incentive to even out our torque, whether from traction or suspension bob, but we're not going to change it by all that much.

**Moralkaka** · 06-05-2015, 03:20 AM

Originally Posted by alewi11

I just picked up a chinese knockoff from ebay. I haven't tried it yet. $.99 plus $12 for shipping. Figured it was worth a shot.

Care to share that link?

**Damian Sanders** · 06-05-2015, 08:26 AM

Originally Posted by jono

It's easy to feel yourself pushing fore and aft on the pedals when the crank crosses vertical, but if you quantify that and compare it with the force applied mid-stroke you'll notice that even a comparatively circular pedal stroke goes almost to zero torque at top dead center. It's not at all like turning a crank using your arm/hand. Even with a "circular" stroke you'll still notice and probably benefit.

No, I actually have a pretty well refined circular stroke where I'm producing good power with the cranks vertical, while not mashing in the lower part of the downstroke. I pedal seated 90%+ of the time. While it may not be the most efficient or powerful stroke, it works well for technical riding.

**jono** · 06-05-2015, 09:08 AM

Originally Posted by Damian Sanders

No, I actually have a pretty well refined circular stroke where I'm producing good power with the cranks vertical, while not mashing in the lower part of the downstroke. I pedal seated 90%+ of the time. While it may not be the most efficient or powerful stroke, it works well for technical riding.

I was assuming seated pedaling and heavy use of ankles/calves. Having just been through a fair amount of research on this topic, I haven't run into any examples that support what you're suggesting but I'd love to hear it if that's possible so, serious question: have you measured your torque throughout the stroke, or how are you reaching the conclusion that it's even throughout?

A while back I was hoping to measure torque vs. crank angle myself but discovered that (virtually?) all the power meters out there assume roughly constant speed and have a very low sampling rate relative to cadence so I eventually bagged that in favor of finding existing data. But if there's something I missed I'd be interested.

**Damian Sanders** · 06-05-2015, 10:43 AM

Originally Posted by jono

I was assuming seated pedaling and heavy use of ankles/calves. Having just been through a fair amount of research on this topic, I haven't run into any examples that support what you're suggesting but I'd love to hear it if that's possible so, serious question: have you measured your torque throughout the stroke, or how are you reaching the conclusion that it's even throughout?

A while back I was hoping to measure torque vs. crank angle myself but discovered that (virtually?) all the power meters out there assume roughly constant speed and have a very low sampling rate relative to cadence so I eventually bagged that in favor of finding existing data. But if there's something I missed I'd be interested.

Most studies are done with pro road bikers riding at high output, who are all basicly pedal mashers, they make very little power when the cranks are vertical.

Circular pedaling is very easy to prove, simply pedal with only one foot.

**jono** · 06-05-2015, 11:29 AM

Unfortunately, for that purpose, momentum ensures that you can ride with one leg regardless.

I completely agree that mountain and road differ, but the magnitude is the issue. Assume that Tomac is 3 times as smooth as a roadie and that you're 3 times smoother than that, you'd still vary by about 30% whereas oval rings only correct another ~10-15%. So you'll be better than now with the ability to get more efficient, even if you're in the top 0.1% on smoothness.

Which muscles are you firing at TDC?

**pureantigravity** · 06-07-2015, 05:10 AM

They are all the rage today. All the rage.
Is it Elliptical or Oval?
Except I see a lot of mtbr pros racing and winning without them.
Do they work with an E-13 chain retention system?
Any good Enduro races or XC races being won by people that stoup to oval levels?
Will my ankles adjust to working at different points?
Is there any post-purchase dissonance?
Will I enjoy the placebo effect?
Who isn't drinking the koolaid?

**BushwackerinPA** · 06-07-2015, 05:44 AM

I just bought a 34 tooth for me yet to be here bike from wolf tooth. The OP has an oval ring I think he just needs to update what his thoughts on it,

**jimmyjames11** · 06-09-2015, 05:15 PM

Been riding an absolute black oval on a 1x11 set up and I love it. I definitely was not a proficient climber with an even pedal stroke but this has seemed to correct what I was doing wrong and works great. Not missing anything on the 3x9 set up I got rid of

**ticketchecker** · 03-14-2016, 04:10 PM

Bumping this up. Building up a new frame and buying a whole drivetrain, 1x11. Anyone have more feedback on the ovals?

I had the biopace back in the day, haven't missed it.