Just two years ago SRAM launched its AXS electronic groupsets with radically reimagined gearing. Dubbed ‘X-range’ the intention was to provide that holy grail of a wider range with smaller jumps between gears.
But the smaller chainring sizes – 50/37t being the largest – weren’t fully adapted by the pro peloton. Trek Segafredo was one example, with the team being spotted using the ‘standard’ gearing of 53/39t chainrings.
SRAM manufactured larger rings specifically for the pros, but now those options are being opened up to the mass market. SRAM says this is largely because the UCI requires that products used by the pros are available for consumers and that the X-Range gearing is still best for most amateurs – but we’d be interested to see how widely adopted the new options are.
As of today new gearing options for SRAM RED eTap AXS Power Meter Kits will be available on SRAM.com. Each chainring option comes with a special and required two-position RED eTap AXS front derailleur. These chainring/power meters are also part of the power meter exchange program.
The available size options are, 52/39t, 54/41t and 56/43t, and they will set you back $1,349, €1,300, or £1,160.
Why were larger chainrings wanted?
Crucially, it’s not the size of the gears that was the issue here. A 50 tooth chainring coupled to a 10-tooth cassette sprocket gives a gear directly equivalent to a 55×11 gear – which is larger than the 53×11 top gear used by most pros.
Rather, the concerns regarded the articulation of the chain – how much it has to bend to wrap around the sprockets. The more a chain has to articulate, the more watts are lost due to friction between the rollers. It’s because of this that we often see over-sized jockey wheels being added to rear derailleurs.
So, if 11-tooth jockey wheels are being deemed too tight a wrap and replaced with 19-tooth oversized ones, you can imagine what a dim view ‘chain-articulation’ weenies took of the 10-tooth smallest sprocket of the AXS groupsets.
But it’s not just the largest gear that is the concern. With a smaller chainring, you’re going to need a smaller sprocket to get an equivalent gear for the entirety of the cassette. You’ll on the 14-tooth sprocket as opposed to the 15 with a larger chainring. The efficiency worries are there throughout.
These larger chainrings that have just been released by SRAM will allow riders to use the larger sprockets of the cassette and should deliver a little bit of an efficiency boost.
It’s worth pointing out that this is likely to be extremely marginal. Ceramic Speed only claims a 2.4 watt saving of their Oversized Pulley Wheels System over the standard Shimano system, and the differences in tooth sizes here are much smaller than that.