Review: absoluteBLACK MTB Oval chainring 104bcd 32t

This oval chainring from absoluteBLACK could smooth out your ride
No, it’s not Biopace. Yes, it’s worth trying to see if you like it. Mechanic and frame builder Liz Colebrook tests the absoluteBLACK MTB Oval chainring

From 1893 to 1983 oval chainrings came in and out of fashion, usually every other decade. Unfortunately, Shimano’s Biopace didn’t get its marketing right – or the product – and it’s taken 30 years to wipe the slate clean.

The recent renaissance took hold thanks to the marginal gains philosophy, advances in design and machining, and an explosion in new riders who haven’t learned the smooth-pedalling ‘souplesse’ of more experienced cyclists.

Whether on road or off, these new generation oval chainrings smooth out the 12 o’clock dead-spot known as top dead centre (TDC) by reducing the effort to push past this point. As the power phase begins on the down stroke, the ovality evens this out, resulting in a little bit of souplesse for the masses.

It’s arguably kinder on the knees as the gear is effectively lowered where the stroke is weakest. My experience was positive. There’s a short period of acclimatisation when pedalling feels ‘gooey’ but this soon fades.

The benefit when climbing hills is noticeable. It’s easier and smoother. It’s also particularly suited to 1× gear systems, as a single ring means no risk of a dropped chain during front shifting.

You can test the ‘smoothing-out’ theory by riding a knobbly tyre on flat tarmac with a round chainring. If you lack souplesse, you’ll probably hear a rhythmic buzz as the torque changes through the 360 degrees of the pedal stroke. Fit an oval ring and this ‘bouncing’ should disappear.

A smoother delivery of power will logically reduce wheel spin and increase traction, especially on technical climbs. Just bear in mind that this is only one piece in the puzzle. Having the appropriate crank length, saddle position and shoe/pedal combination are all influencing factors in performance and comfort.

absoluteBLACK has done its research, as evidenced on its website. The company offers a wide range of both oval and round chainrings compatible with most quality chainsets designed for mountain, road, gravel, and cyclocross bikes. I tested a red anodised 32-tooth chainring (104mm bolt circle diameter) intended for 1×10/11/12 or singlespeed applications.


Worth trying on hilly terrain to ease the knees, improve traction off-road, and keep your pedalling strokes smooth and efficient as they deliver power.

Other options

Hope Oval Retainer Ring 104PCD £40

Hope Oval Retainer Ring 104PCD black chainring

This ring has 12% ovality and 113º clocking (rotational position). It weighs 48g (32t). Six colours.

Rotor 1X QRing 110×4 £68

Rotor 1X QRing 110×4 black chainring

Rotor makes lots of oval rings, including some with adjustable clocking. But this one (right) is a simple 12.5% ovality ring.

First published in Cycle magazine, April/May 2020 issue. All information correct at time of publishing.

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At Cycling UK and Cycle magazine, we are proudly independent. There’s no pressure to please advertisers as we’re funded by our members. Our product reviews aren’t press releases; they’re written by experienced cyclists after thorough testing.

Tech spec

Price: £59.99.
Sizes: 64BCD: 26T (35g), 28T (42g); 104BCD 30T: 36g – comes with special bolts and spacers; 104BCD: 32T (41g, tested), 34T (44g), 36T (53g).
Available from: absoluteBLACK.

Pros & cons

+ Can improve pedalling efficiency
+ Low-cadence traction
– Reduced clearance to chainstay