This article first appeared on BikeRadar.
There’s no denying the simplicity and popularity of dedicated single chainring drivetrains. But there are trade-offs with cadence and gear range. Easton is hoping to eliminate those downsides with its new gravel, adventure and cyclo-cross double chainrings.
Easton’s double chainrings come in three sizes, each intended for different drop bar genres. According to Easton, 47/32t is for gravel, 46/36t is for cyclo-cross, and 46/30t is built for adventure riding.
Easton two-ring specifications
- Claimed weight: 47/32t 194g, 46/36t 192g, 46/30t 182g
- Claimed weight on Easton EC90 SL crankset: 540g (172.5mm 47/32 without bottom bracket)
- Chainline: 45mm
- Material: EA90 aluminum
- Price: $149.99 (UK and Australian pricing TBC)
- Available now
The timing of Easton’s two-ring chainring release corresponds well with Shimano’s recently unveiled clutch-equipped Ultegra RX rear derailleur.
Unlike SRAM’s clutch-equipped rear changers, the UItegra RX rear derailleur is compatible with double chainrings up front.
Easton claims a 45g weight saving by using direct-mount rings, which eliminate the need for a chainring spider.
Correct gearing for gravel
The gravel set features 47/32 chainrings
Easton is touting a few reasons behind the unique 47/32 chainring size.
In a nutshell, Easton is claiming standard road bike gearing (53/39, 52/36 and 50/34t) — which was made for light, aero bikes with narrow tires riding on hard, smooth asphalt — is too tall for gravel bikes with their big tires, non-aero frames and rough, slow-riding surfaces.
Why a 47 and not the more common 48 chainring for a sub-compact big ring? Easton claims it found the only time gravel speeds exceeded 54kph / 33.5mph was on descents where pedaling would not make an impact.
For the low end, Easton found the 32t ring ideal, as it provides a 1:1 ratio when paired with the common 11-32t cassette.
Easton also touts increased shifting performance. With a 15-tooth spread between the rings versus the more common 16t. This lessens the cadence jump when shifting the front derailleur.
Additionally, Easton claims that with its 47-tooth ring it can optimize the shift ramps better than it could with a 48-tooth ring.
A short spread for cyclo-cross
For cyclo-cross, Easton is offering a 46/36 option
The cyclo-cross-targeted chainrings are 46/36t. Easton states its sponsored ‘cross riders requested this combo.
Easton claims the 10-tooth spread delivers quick front shifts and requires fewer rear shifts to minimize the gearing gaps.
According to Easton, having a 36-tooth small ring gives an easy gear for steep inclines and a natural dismount cadence for when riders have to hop off and run.
On the high end, the 46-tooth big ring has enough speed for pavement sections and finish-line sprints.
High and low for adventure
Adventure bikes get a 46/30 wide-range chainset
A lot is asked of adventure bikes. Often times they’re loaded tip to tail with gear then ridden up, over and around some desolate and rugged terrain.
Easton believes 46/30t chainrings provide a suitable range with an ultra-low gear that’s ideal for slogging up steep roads, yet a big enough gear on the opposite end to click off the miles or maximize downhills.
The 16-tooth spread is within front derailleur standards. Easton acknowledges there’s a bit of shifting performance trade-off for the massive gear range.