This particular chainring will only work with CN-M9100, 8100 & 7100 Hyperglide+ 12S chain due to different thickness and shape of the teeth. The premium 1X RaceFace Boost 148 direct mount narrow wide Oval chainrings are designed for Cinch systems, RaceFace uses to mount chainrings directly to the crank. This version is for Boost specific bikes and Fat Bikes (when reversed).
Difference between Boost 148 and non-boost chainrings is in the offset/dish of the chainring itself only. You would use same crank in both boost and non-boost bikes, but chainring offset has to be different to accommodate chainstay clearance. Boost chainrings have only 3 mm offset while non-boost ones 6 mm.
Why oval chainrings work
Oval (elliptical) 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
Traction, Traction and Traction. With oval rings the rear tire traction improves greatly on loose and slippery terrain. 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.
- Compatibility: RaceFace Cinch system cranks. RF Next SL G4, Next SL, Next R, RF Sixc, RF Turbine, RF Atlas, Aeffect, Ride Cinch cranks. Shimano 12S Hyperglide+ chain only.
- Material: cnc machined 7075 Txxx Aluminum. Long-lasting construction.
- Finish: type II anodizing.
- Chainline: 52 mm, 3 mm offset.
- Ovality: Optimized to each size separately. Range: 10.2-14.4% and Timing of 110.5-116.3° after TDC (top dead center) Patent Pending.
- Real weight : 30T (54 g), 32T (59 g), 34T (62 g).