Oval Narrow/Wide - anybody got one?

[FlimFlamvanHam]

I think it has less to do with high cadence and more to do with low rolling resistance and smooth ground. That said, if the shifting can be done cleanly from a 40t to a 53t, I would definitely see application in ITTs where constant power output is important.

And that is where they are most commonly used in RR. However, due to how even and efficient a well spun high cadence pedal stroke is, there just is not that profound dead spot in the stroke as found in a low cadence, high torque, longer crank arm (usually relative to road) application like in mountain. This, to me, is why the buy in for road and even time trials has not been like it is in mtn biking. The difference is just not there.

[SchralphMacchio]

They'll all be narrow/wide tooth profile so no chain retention device needed with a clutch rear derailler. Others may argue that a chain guide is a good idea, but I've only ever dropped chains on worn out narrow/wides.

Fixed it for you I dropped my chain on my XTR long cage RD 1x10 setup just once, but it was on a super stacked sequence and I think I got pedal strike or something. Very easy to reseat the chain and jump back on.

[SchralphMacchio]

I also wonder if anyone is wild enough to try an oval ring fixed gear track bike with a chain tensioner (wait, would one be needed if the # of teeth engaged is constant?). Not sure if the benefit of more even torque could be realized in velodrome applications.

I have a single speed city bike, but it's a 5-bolt pattern, otherwise I'd totally be willing to test this out!

[XtrPickels]

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.

While circular pedaling may be mechanically efficient, it is not metabolically efficient. Applicable for certain situations, but limited use in general cycling.

(This is literally my job)

[XtrPickels]

Anyone have thoughts on the stiffness of a direct mount chainring vs. ring + spider combo.

[aragon]

Anyone have thoughts on the stiffness of a direct mount chainring vs. ring + spider combo.

I don't think there is a discernible stiffness difference (assuming MTB ring sizes 28-34 teeth - if it is a road ring it may be an issue if you push 1000+ watts... ), but there certainly is a weight difference. And DM is much cleaner looking, imho.

[FlimFlamvanHam]

^^ this. 7075 is pretty bloody stiff, especially in the thickness these rings are machined to, not to mention it's a very small radius (using that loosely as know the subject is ovals here) on these rings.

And thanks SM, i just assume a clutch derailleur is being used when talking 1x.

And if you haven't seen the new 1x12 stuff from SRAM go find the feature posted today on PB. Check out the teeth on the new ring.

[Damian Sanders]

^^ this. 7075 is pretty bloody stiff, especially in the thickness these rings are machined to, not to mention it's a very small radius (using that loosely as know the subject is ovals here) on these rings.

Actually, 7075 T-6 the same stiffness all other aluminum alloy. It's just stronger. Most light parts built with 7075 are going to have more flex than a heavier part built with a lower grade of aluminum alloy, assuming a similar design.

[jono]

Fortunately, one less part and four less bolts is not a similar design. Spider arms aren't as straight/planar as the ring, either. Anyway, they should be similar enough not to tell a difference, but technically every DM is different so anything is possible.

[Damian Sanders]

Fortunately, one less part and four less bolts is not a similar design. Spider arms aren't as straight/planar as the ring, either. Anyway, they should be similar enough not to tell a difference, but technically every DM is different so anything is possible.

Without doing any analysis, I would expect the spider design to be stiffer all around, and significantly heavier. IMHO.

[Damian Sanders]

Just ordered a 32T Absolute black 104mm Oval....we'll see. Should get it some time next week.

[epic]

It smooths out the power stroke, eh. OK.

Can they make an egg shaped ring to also compensate for my stronger left leg?

Yes they can. At least if you are Fabien Barel they can. He used this for World Champs in Canberra when he had a busted knee.

[Damian Sanders]

Just ordered a 32T Absolute black 104mm Oval....we'll see. Should get it some time next week.

My order for the AB rig didn't go through, ended up with a Blackspire 32t oval from CRC for $42. Seems to be working like it should, but can feel choppy when pedaling lightly.

[epic]

Since I'm the one that started the thread I think I should update. A year ago, I ordered a Rotor narrow/wide oval ring, that didn't last long as I didn't realize they only do the oval NW rings in a proprietary bolt circle for Rotor cranks. So that went back and I got a 34t NW oval from Wolf Tooth. OK, it felt a little different on the first ride, but I was sold as soon as I got onto some tricky climbs where traction is at a premium. I don't think that it gives you more power (how could it?), but it does even out the power and makes it easier to maintain traction. I think it likes a lower cadence, and makes it easier to climb standing. I'm running it on 11spd XTR drivetrain but with an older XTR M980 crank. No issues with chain dropping or falling off when ratchet pedalling. I do think it's noisy in the larger cogs due to chain line (it is offset 2.5mm), but I have found that to be the case with other NW rings as well. Oh yeah, round rings feel terrible now. They feel like what you'd expect an oval ring to feel like. Lumpy. Never say never, but I'd never go back. Also, of the 4 people that ave tried my bike with the Wolf Tooth ring, 4 have purchased oval rings for their bikes too. Try it. You won't regret it.

[SchralphMacchio]

^ good to hear! As soon as my RF Cinch 30t wears out, or if I feel I don't have the chutzpah to push a 30/42 up some of the steeper hills around here, it's being replaced with a direct mount oval.

[gunniride]

I have a wolf tooth oval ring as well. it works as advertised, but you quickly forget about it.

Easiest way to know its working is using a low traction or worn out rear tire that skids just a bit on dry steep climbs with every hard pedal stroke. Oval just smooths it out.

[Andeh]

Interesting to read this. I tried a OneUp 32t NW last summer and hated it. I think the problems were that I'm used to a 30t, and also the OneUp may have had a worse chain line than my stock XT 1x11 setup. I went with the 32t because a lot of manufacturer propaganda says "feels like a size smaller on the hard part of the stroke, a size bigger on the easy part", so like an idiot I was like "well that means I can size up for no extra effort!". Anyways, I'm not strong enough to hack a 32t up front so I went back to a 30t I was used to. In hind sight, like someone several posts up said, I should have got the same size, and made sure that the chainline offset matched the stock setup. Maybe I'll give it another go with a WT 30t one... I like their round NW rings.

[Dantheman]

Pre-season bike fiddling bump: Is there any consensus on what brand to go with on these? Are the offerings from AB/WT/Blackspire functionally equivalent?

[radam]

Pre-season bike fiddling bump: Is there any consensus on what brand to go with on these? Are the offerings from AB/WT/Blackspire functionally equivalent?

I believe the Wolftooth ones are less oval'd than the Absolute Black's and OneUp's. I only have time on AB's ovals but got a deal on a OneU ring and will be running that this season. I definitely find them oval to help, particularly any time I'm a gear or two higher than I should be on a short climb and feel like I'm about to stall out.. with the dead spot minimized (or rather, made slightly easier), I'm just a little more likely to be able to push through it and keep on going. OneUp is still running deals on their oval rings direct from their site. $30 for SRAM/RF direct mount rings in the sizes they have left. Hard to go wrong.

[Dantheman]

OneUp is still running deals on their oval rings direct from their site. $30 for SRAM/RF direct mount rings in the sizes they have left. Hard to go wrong.

That is a great deal, too bad I need a 104 ring.

[cmcrawfo]

Interesting to read this. I tried a OneUp 32t NW last summer and hated it. I think the problems were that I'm used to a 30t, and also the OneUp may have had a worse chain line than my stock XT 1x11 setup. I went with the 32t because a lot of manufacturer propaganda says "feels like a size smaller on the hard part of the stroke, a size bigger on the easy part", so like an idiot I was like "well that means I can size up for no extra effort!". Anyways, I'm not strong enough to hack a 32t up front so I went back to a 30t I was used to. In hind sight, like someone several posts up said, I should have got the same size, and made sure that the chainline offset matched the stock setup. Maybe I'll give it another go with a WT 30t one... I like their round NW rings.

A 32T elliptical ring will provide a ratio closer to 31T circular. I believe that this aids in the perception that they they make pedalling easier.

I have used a few different elliptical rings on a few different bikes. I don't think they are magic bullet, or for everyone. I like them on some bikes and hate them on others. I don't have a sound explanation as to why, but that's just how I found them. I have also found that the slight variation on the orientation of the ellipse between brands is more noticeable on my hardtail. I like the rings that provide multiple mounting options, so you can get the ring oriented in a position that's right for your body mechanics.

Road teams have done a bunch of research into these rings, and I think the consensus from the professional road community is that they do nothing to increase performance. I think there is some data from team sky floating around the interweb that supports that... and of course there are just as many blogs saying the opposite.

regardless if it improves performance, it has the ability to improve comfort and they are worth a try for anyone who hasn't used one... Just don't expect magic and rainbows.

[Touring_Sedan]

Pre-season bike fiddling bump: Is there any consensus on what brand to go with on these? Are the offerings from AB/WT/Blackspire functionally equivalent?

If you're still looking for one, I have an Absolute Black 30T Cinch that you can have. It wasn't for me.

[SJG]

One more data point: I have more traction (less likely to spin out), and my knees don't get as sore, with my AB Oval compared to a round chain ring.

[Andeh]

I have the 30T AB ovals on both my bikes(Nomad, Mojo HDR 650b), and really like them. I find they smooth out the stroke nicely. I tried a 32T OneUp oval and didn't like it... too large for fire road climbs for me and somehow just felt off.

A buddy of mine just rode my HDR the other weekend having never used an oval before and said something along the lines of, "This pedals different, but not in a bad way. What's going on?" I told him it had an oval ring, he said that must be it. He said it felt like he was able to get more out of the end of each stroke (rubbing gum off your shoe is how he put it). He was using clip-in pedals & I use flats, FWIW.

[jono]

A 32T elliptical ring will provide a ratio closer to 31T circular. I believe that this aids in the perception that they they make pedalling easier.

What is this referring to, the short axis of the ellipse? On which brand? AB was saying a 32T was more like a 30T at the low and 34T at the highest last I checked and the one I bought last fall for my wife seems about +/-2 like that, although it's a 26T.

Of course, the total average ratio is exactly the same as a round one, (unless they shorten the distance between teeth, which would break chains a little better). I would be suprised if the same degree of ovalization is optimum for both low rpm and high, so mountain vs. road seems like it would prefer different shapes FWIW.