Our premium 1X Aero Sram® Direct mount Oval chainring is designed for Sram cranks like Force and Rival where spider can be replaced with direct mount chainring. Fits both GXP® and BB30 spindle cranks. This is 1X narrow-wide chainring. Ideal for Triathlon, Criterium and Time Trial. Our premium 1X Aero Sram® Direct mount Oval chainring is designed for Sram cranks like Force and Rival where spider can be replaced with direct mount chainring. Fits both GXP® and BB30 spindle cranks. This is 1X narrow-wide chainring. Ideal for Triathlon, Criterium and Time Trial. Why our oval chainrings work Our premium Oval chainrings work because a rider does not produce power evenly through a pedal stroke; they maximize the part of the stroke where power is produced and minimize resistance where it isn't. Oval rings make the spin cycle a lot smoother and are easier on legs while climbing. Believe it (or not), but a round chainring doesn't transfer torque to your rear wheel as smoothly as an Oval one. You will actually feel your stroke to be more "round" with an Oval shape than with a round chainring. Why it matters Smoother power delivery to your rear wheel means that you will be able to maintain better, constant cadence; get less stress on the joints (knees) and therefore be able to keep certain level of effort for longer. This results in higher average speed. Moreover, 11 studies made by various Universities in the World show that using oval chainrings human legs utilize more muscle groups (compared to round one), but each of them to lesser degree. Load from pedaling an oval chainring is spread over greater muscle mass which in effect gives you the feeling of fresher and more relaxed legs. This in turn let you achieve higher average speed riding uphill. Another benefit from spreading the load over more muscles is reduced risk of having a cramp while riding and much better overall feeling after the hard ride. Why our Oval chainrings do not have adjustable timing Because we have discovered that small adjustments made from our Premium timing position is just splitting hairs. There is great advantage coming from round to oval. But adjusting oval itself from our premium position does not bring more measurable advantage. Non adjustable rings are also much lighter and very easy to mount, letting you not to worry about all the possibilities you could have with adjustable ring. Why our oval chainring is more aerodynamic than any other offering. Firstly, direct mount full body chainring will always be more aerodynamic than 4 or 5 bolt spider options. Secondly, our unique grooved outer surface reduces drag even further. It is well known feature that the drag coefficient on a dimpled golf ball is much lower than that on smooth ball. Numerous studies showed that turbulence is generated through the instability of shear layer separating from the edge of dimples and delays flow separation which makes it more aerodynamic. Dimpled structure generate 220% less drag than a smooth surface. However recent studies made by golf industry leaders show that new grooved surface can be made with almost same drag reduction vs smooth surface. Why it matters? Because grooved surface is more practical to manufacture on various bike parts like chainrings. Grooved surface could greatly reduce drag generated by big smooth „aerodynamic” chainrings currently offered on the market. Few facts you should know: *It is well documented that grooved surface on the sphere generates less drag when rotating well below 150rpm. In fact it generates least amount of drag when not rotating at all! *It is well documented that grooved surface generates least amount of drag when traveling at speeds around 10-15m/s (36-54km/h) These parameters fit well to how we ride the bike. Hence grooved surface on various flat parts, like Absoluteblack Aero chainrings is the most preferable way of further drag reduction.