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I find this intriguing... but can't quite wrap my head around it just yet. So... the key is that the oval is in the "long" position when you step on your pedals, maximizing rotation during your step downs but minimizing it during the less efficient part of your pedal stroke? I'm thinking of making the leap from 2x10 to 1x11 - should I go standard first to get the feel or consider going straight to the oval up front?
TahoeJ, I can see no downside at all in getting the oval to begin with.
A good riding buddy of mine claims to notice little if any difference between oval and round. D(C) on the board here posted up that he too notices little difference. To me it is not night in day feel wise, but it really is a very noticeable difference in a positive way under slow cadence high torque situations.
jm2e, there is no one source for chainring chainlines between makers. Google and the manufacturer's websites are about it.
Suffice it to say 50mm is about the norm for the middle ring position on a standard 104BCD crank capable of taking 3 rings.
SRAM 1x's are 49mm and Shimano are 50.4mm.
Most of the aftermarket players doing direct mounts (SRAM direct mount or RF cinch) are 49mm. I really do not know anyone going less than 49. That would be dictated by mounting an offset ring in the middle slot on the triple or mounting a smaller BCD ring on the inner spot on same.
+1 on not noticing except at low rpm, but I've talked to several people who say they love them for high rpm, so I figure it must not hurt there, either. It does seem like everyone who hated Biopace should hate round after getting used to a proper oval, so that sort of makes sense. Evening out chain tension a little has an obvious benefit for stabilizing the rear end that usually goes unmentioned, too.
All in all, Shimano really screwed us with that crap--I hope when they finally start mounting ovals on OEM they have the balls to call theirs Biopace3.
Just do it, and do it all at once while you have your crankset taken apart, etc. I personally haven't tried oval rings but I see no reason to doubt it, as the mechanics of new-school oval clocking to maintain constant torque and improve traction on steepish, loose-ish rocks etc. all seems very sound to me.Quote:
Originally Posted by TahoeJ
Sizing ...
For Bay Area and Tahoe I found a 30t round up front and 11-40 in the back to be just right on. I used 40 instead of 42 because factory 10x RDs shift much cleaner that way ... going to 42 seems like you need to modify the cage and/or hanger mount to get clean shifting.
There's a separate 1x thread so we can continue the RD setup discussion over there.
It smooths out the power stroke, eh. OK.
Can they make an egg shaped ring to also compensate for my stronger left leg?
Bike options are confusing.
Does it make sense to get an oval ring if I swap my Spartan from a 2x10 to a 1x10 (eventually an 1x11)? Or is an oval ring a better option for a XC bike?
Did an oval front ring come about because we are lazy and will getting stronger riding legs have the same affect? And if the oval ring makes riding easier, no matter how strong your legs are, why don't we see the pros using them, or do we and I just am too much of a noob to see it?
You will see them all using them. Ovals in MTB are relatively new and pros have to ride what their sponsors can and will supply etc. Also, this is not Biopace. In road they've been around for many years and the jury is out. Frankly, in high cadence applications like road riding I fail to see how they can be of any merit, but what do I know?
For the way mtn bikes are pedaled they make a ton of sense and actually provide some benefit.
Obviously they were not invented to satisfy a need. But it turns out they are more effective at equalizing the torque through the entire revolution of the crank (relative to a round ring). Invention is the mother of necessity.
If you're going 1x and starting fresh I cannot understand why anyone would not go oval if they have to get a ring.
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.Quote:
Originally Posted by Johnny Sizzler
Ok, that makes sense. I need to get a new ring, I don't think I can just take my big ring off since when I'm cruising downhill I don't have much power shifted all the way up on the small ring. I'll check out the oval rings listed early in the thread.Quote:
Originally Posted by Johnny Sizzler
This might also sound silly, but are hole patterns fairly universal so I should be able to get an oval and it should just bolt on?
Also, can I, or do I need to, run a chain guide (or chain retainer attachment) with an oval front ring? If like to stop dropping chains when it gets rough coming down hill. If yes, any suggestions on one that is light and works well?
yes, they are available in the commonly used bolt patterns, namely 104 and 64. Also for the new shimano stuff and the SRAM 94 4 bolt stuff.Quote:
Originally Posted by skibrd
They'll all be narrow/wide tooth profile so no chain retention device needed. Others may argue that a chain guide is a good idea, but I've only ever dropped chains on worn out narrow/wides.
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.Quote:
Originally Posted by SchralphMacchio
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.Quote:
Originally Posted by Johnny Sizzler
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!
While circular pedaling may be mechanically efficient, it is not metabolically efficient. Applicable for certain situations, but limited use in general cycling.Quote:
Originally Posted by Damian Sanders
(This is literally my job)
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.Quote:
Originally Posted by XtrPickels
^^ 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.
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.Quote:
Originally Posted by Johnny Sizzler
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.Quote:
Originally Posted by jono
Just ordered a 32T Absolute black 104mm Oval....we'll see. Should get it some time next week.
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.Quote:
Originally Posted by puregravity
Attachment 183583
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.Quote:
Originally Posted by Damian Sanders
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.
^ 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.
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.
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.
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.Quote:
Originally Posted by Dantheman
That is a great deal, too bad I need a 104 ring.Quote:
Originally Posted by radam
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.Quote:
Originally Posted by Andeh
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.
If you're still looking for one, I have an Absolute Black 30T Cinch that you can have. It wasn't for me.Quote:
Originally Posted by Dantheman
https://uploads.tapatalk-cdn.com/201...07dcf849fb.jpg
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.
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.
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.Quote:
Originally Posted by cmcrawfo
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.
More ovalization being better for lower RPMs?Quote:
Originally Posted by jono
That would be my guess, just because at low rpm an "unbalanced" feeling matters less so you could go past whatever is optimum for spinning fast. Maximizing rpm range might mean something in between?Quote:
Originally Posted by Dantheman
Went AB. CRC had them cheap and they look to have meatier squarer tooth profiles than the OneUp rings. I really like it. I'll agree with others that it's not a huge difference, but the smoother power delivery and easier turnover past TDC is definitely noticeable while grinding uphill. While spinning fast riding flat road between the house and the trailhead I could feel the oval, almost like a very tiny amount of pedal bob, but only if the pavement was really smooth and I really paid attention. Felt great in all other circumstances. Altachic likes hers a lot too.
What didn't you like about it? If no local Utards wanna take that off your hands, I might be willing to buy it off you, if you can drop into an envelope and ship to California.Quote:
Originally Posted by YourMomJustCalled
I just bought a 32t round narrow wide to replace the oval that's currently on my yeti SB66, when I put on a new crankset. I don't think the oval works particularly well with the chain growth/rearwardish path of the yeti's suspension, it seems to produce too much pedal feedback (hangs up) riding technical terrain at lower speeds and cadences, and doesn't seem to do much to help with suspension bob or technical climbing. But I'm going to try them both back to back if possible and will also try the oval on a hardtail.