Have they got it right this time? Memories of Biopace (and Biopace knee!) I’m looking to get a bigger ring up front (RF NW 32t with x10 at the back). I do feel I need a bigger ring so was looking at a 34t oval. Are they the best thing since fresh crusty baguettes or is a load of marketing bobbins that the fad-ists are jumping on?

Works for me. Absolute Black 32t on 1×11 and SS.

I had one on my single speed, knees were fine but the drive chain felt horrible like something was broken. Much prefer the smoothness of a round ring

Works for me on a singlespeed. However, the narrow-wide is unnecessary if you’ve got no tensioner, and can make it a bit crusty/crunchy when riding anywhere gritty/sandy as it doesn’t clear off the ring so well.

Its a small price to pay on my other bike, a 1 x Alfine with tensioner that used to drop the chain. (not an oval but is a narrow-wide)

P.S it now feels smoother than a round ring, you do need to make sure you line up the mark with the crank so the oval is at the correct orientation. I put the singlespeed on the rollers for a laugh and you can feel the gear ramp up on the downstroke but its undetectable when riding in ‘real life’.

Watched the videos on Absolute Blacks website, couldn’t possibly be disputed….

Hi
A vote from me in favour of the AbsoluteBlack 32 oval, mine has improved hard pedalling significantly d its a nice green shade too. .it is narrow wide, on 1×10 with an XT cassette and a oneup 42. I am very pleased with the performance, it also seems to be lasting really well.
I use their taco plate too. Nice and simple. My Saint mech does gave a clutch but I rarely have it on and the chain stays on regardless. I think absblack have been clever with their narrowwise interpretation.)
My experience is entirely positive.

With gears…not sure.
Singlespeed yes, been running one for a few years now, wouldn’t go back.

upsides definitely outweigh the downsides for me. It is a bit louder (i’ve a narrow wise as well) and I reckon it’s wearing faster. But…it smooths out my lumpen pedal stroke, makes tricky uphill sections a load easier, climbing is a bit nicer. I’m sold.

I have one on one of my bikes and find no benefit at all. I forget about it after a few minutes. It’s just a fad

I’m not going back to round rings, I’d say it’s not a fad but progress.

I’m beginning to see NW as a slight fad, a bit of wear and they start to drop the chain so you need a chain device anyway. I’d like an oval ring with a normal tooth profile to increase it’s life.

I’ve had one for a couple of months now.. Regularly getting new pb’s on climbs since I fitted it. I don’t really feel it while riding.

I’m beginning to see NW as a slight fad, a bit of wear and they start to drop the chain so you need a chain device anyway. I’d like an oval ring with a normal tooth profile to increase it’s life.

But a worn NW is no worse at keeping the chain on than a traditional ring after the same mileage, probably still a lot better. Just run a guide with it, best of both worlds!

aphex_2k – Member

Have they got it right this time?

Yes.

Biopace was 90 degrees in the wrong direction, which made pedalling harder…

So they have just rotated the rings on the spider then basically. How innovative.

Nowt new under (t) sun lad.

But a worn NW is no worse at keeping the chain on than a traditional ring after the same mileage, probably still a lot better. Just run a guide with it, best of both worlds!

If I’m running a guide, I don’t need NW. There doesn’t seem to be an option for an oval ring without NW just now.

Here’s a little read that people who think Shimano with all their research and developement managed to ” get it wrong ” should read .

http://www.sheldonbrown.com/biopace.html

Ramsey Neil – Member
Here’s a little read that people who think Shimano with all their research and developement managed to ” get it wrong ” should read .
http://www.sheldonbrown.com/biopace.html

Nice find.

So they have just gone back to the way it was tried (and found to be bad for the knees) pre-biopace?

If I’m running a guide, I don’t need NW. There doesn’t seem to be an option for an oval ring without NW just now.

NW + guide is still better at keeping the chain on than normal + guide. The NW does most of the work, so the guide doesn’t get as worn, plus you reduce the probability of when the chain gets tangled in the guide.

I fitted an oval a few weeks ago and rather like it. That’s on a hardtail. I’m not sure how well it’ll work on a full-sus because you’ll lose anti-squat when you need it the most, from the change in diameter and chainline.

I’m not a roadie, nor do I ride a fixie and modern ovals don’t look like rugby balls. I don’t get the whiplash effect or sore knees and my climbing is much improved. But Sheldon Brown MUST be right…

Just been riding my my 1×11 Jekyll and loved it.

Absolutely love them; running absoluteBLACK rings on two bikes and can notice the increase in traction straight away. Also feels much more natural when I ride a bike with a round ring. No issues with dropping a chain and run both 1×10 and 1×11.

Worth giving absoluteBLACK’s 30 day money back trial a go!

I’ve got one on the hardtail, tbh I’d forgotten about it, went for a ride today, none the wiser. On the fatbike it definitely makes a difference, you can feel less bounce as you pedal so it’s definitely doing something…

TBH it could easily be one of those things where there’s a benefit but it’s easy not to notice- if it makes pedalling a little easier, I’ll just go a little faster or burn a little less leg, and not necessarily know there’s a difference.

TBH it could easily be one of those things where there’s a benefit but it’s easy not to notice- if it makes pedalling a little easier, I’ll just go a little faster or burn a little less leg, and not necessarily know there’s a difference.

Is it possible that the opposite is true and that oval rings are no different / slightly worse than round ones?

I remain unconvinced. I wonder if these are something we will look back on in a few years as a bit silly – like FlexStems, 69ers and, uh, Biopace.

Love mine, they do indeed seem to take away the bob, and I can climb much smoother. Wouldn’t go back.

Oh and my 69er is bloody ace. Looks slightly odd but rides a dream.

Had a shot of one last week, felt awful. I’ll never use them.

I’ve got them on my bikes. Can’t notice the difference when pedalling but have found climbing is a lot better and more traction. Especially as you start to get tired, the smoothness of the pedal stroke helps. IMHO it helps you climb / stay out for longer before feeling done in.

Superficial – Member

Is it possible that the opposite is true and that oval rings are no different / slightly worse than round ones?

I reckon so. but the experience of the fatbike does make me wonder- the big bouncy tyres make bob more noticable, just like a coil shock does, but that wasted energy’s got to be there all the time, on other bikes.

On my single speed I find them great for pedaling under load (most of the time) but bloody horrible for spinning where it feels like my legs are broken and bouncy.

So I’m running a 32t chainring on my SS…
Would I just got for another 32t oval ring (34/30 at extremes) or a 34t (36/32 at extremes)??

DrP

I just went 32t to 32t oval.

I have one on one of my bikes and find no benefit at all. I forget about it after a few minutes. It’s just a fad

How can something that works be of no benefit?

I gain enough that I can run a bigger (2 teeth) front ring, which is always better. Means on my HT that 1×11 is rideable with a 32T front ring on the long steep climbs around here and still have top end.

DrP – some do, some don’t. My Googling of such things favoured it on a SS, particularly reducing low cadence deadspots whilst hill honking.

I have one not fitted yet. I can’t remember which way round the wonky is but hopefully it’ll work in my favour and give me more clearance for log hops.

It isn’t that way round unfortunately!

Edco have just brought out an oval cassette, supposed benefits ,it means there is no rear mech wear

IMO,first thing i’d say is forget anything to do with road bikes and oval rings!

On a road bike, if you’re not cranking away at around 80 to 120rpm you’re doing it wrong.

BUT, on an MTB, situations exist where the terrain and massive differences in speed (one moment doing 35mph down a fireroad, the next cranking up through a steep rooty bit of single track at less than walking pace etc) and here your cranking cadence can, and does vary from a flat chat 120rpm spin out to a completely stalled zero rpm stop! And here, for me, the oval ring works. Especially with 1by, when you don’t have the same massive spread of gears as 2by or 3by, i now spend much more time at lower cadences and much higher loads. Having gone oval, i now find I am able to keep turning the cranks at these low rpms, whereas before i would have stalled out as the crank comes “over the top”. There’s two steep rooty climbs i could never get up with my 1by setup, (used to get up them on 2by in granny ring) that i now can get up again 😉

IMO, an oval ring isn’t much more expensive than a round one, especially if you were going to be buying a nice trick NW ring from Hope or AB etc, if you don’t like it, you can go back to round when it wears out, and if you do like it, you can buy another when it wears out….. 😉

Only negative i can find is that it makes finding and fitting a top chain device a bit of a ‘mare, because that device needs to accommodate the vertical chain motion as the ring turns.

Right, I’ve had a think about that sheldon piece…

It seems that the biopace concept follows thusly:

1) Given that the speed of a bicycle is roughly constant*, ideally the speed of the chain should be a constant too.

2) there is a theory that it’s easier to move your feet quickly when your cranks are level, and ideally you’d be moving your feet more slowly at the top/bottom of the stroke.

3) With the long axis of the ‘oval’ in line with the cranks, you need fewer degrees of rotation to pull the chain a given amount, and more degrees of rotation to pull the chain the same amount when the cranks are level.

3 cont.) in other words, your feet need to move slower through tdc, than through level. To maintain constant chain speed and bike speed.

4) doesn’t that like a nice idea? When your foot is at topdeadcentre, all your joints are all bunched up, making it tricky to move them quickly. Biopace means your foot slows down when your joints at their most bunched.

However, it also requires more force to move through tdc with biopace (slower means more force for the same power, that’s just the laws of physics).

And, I’m not sure I agree with point 1), given that I don’t agree with (*), we all know a climb where our movement forward matches our pedal strokes, surging, pausing. The speed of a bicycle definitely isn’t constant, because our force output isn’t constant.

Biopace makes the variation in our force output bigger, in an attempt to reduce our foot-speed at tdc.

In summary, knackers to foot-speed at tdc, smoother force output sounds like a better idea to me. More constant force output = more constant speed on a steep surge-pause climb, which will be great for traction.

In other words, knackers to biopace, old fashioned/new fad ovals sound like a better idea to me.

IMO,first thing i’d say is forget anything to do with road bikes and oval rings!

Best tell Mr Wiggins 😉

qwerty
IMO,first thing i’d say is forget anything to do with road bikes and oval rings!
Best tell Mr Wiggins

I didn’t mean that ovals don’t work on road bikes, just that when it comes to MTBs the requirements are IMO, very different indeed!

For most people (ie not Wiggo 😉 ) any tiny difference in pedalling efficiency brought by oval rings on road bikes will be offset 10x or more by just training more / smarter! If you ARE at your peak performance (like wiggo) then the tiny extra improvement from oval rings could make a difference.

But for the average MTB rider, not racing, just wanting to cover the best terrain (ups, downs, flat, technical bits, gnar etc!) an oval ring again, imo, brings most advantages when paired with a 1by transmission that has, by it’s very nature, a more limited total gear range!

Articles talking about knee strain for road riders are pretty irrelevant to the average mountain biker, who rides at a much lower cadence than a fit road rider (who often spend many more hrs just spinning away in the saddle!). So, if you are training for 30hrs a week on a road bike then yes, small changes to pedalling geometery that might reduce knee strain could be worthwhile, but for the average mountain biker, spending a hr or two messing around in the woods, they’d swap the ability to clear a tricky steep climb for the potentially slightly increased knee load i suspect??