Cyclist
New SRAM Red XPLR AXS is 13-speed and uses an Eagle Transmission-esque full-mount rear derailleur
After branching out from road with original XPLR in 2021, the new SRAM Red XPLR AXS groupset now fully diverges from its roots, becoming an entirely different proposition specific to gravel.
It uses a 10-46t, 13-speed cassette paired with 1x chainset that uses Thread Mount chainrings, which screw on to the crankset spider.
The rear derailleur, although not exactly the same in design as those in SRAM’s Eagle Transmission series, borrows many features from that line, including a hangerless/full-mount interface and replaceable subcomponents.
The Red XPLR AXS rear derailleur requires framesets to have the UDH fitment standard, which is becoming more widespread in gravel and now even road.
Despite the bulkier derailleur, SRAM claims the Red XPLR AXS groupset sheds over 200g in weight compared to its predecessor, with the main savings coming in the cassette, crankset and controls.
SRAM Red XPLR AXS is available immediately as OE on bikes from over 20 brands and available aftermarket too. Prices for full groupsets start from £3,530 / €3,960 / $3,529.
In conjunction with new Red XPLR AXS, Zipp has launched new 303 XPLR gravel wheels, tyres and handlebar, which we have covered with their own news story.
A decade in the making
With its then cyclocross-focussed Force 1 arriving in 2013, SRAM has been offering groupsets for rigid bikes to use off-road for more than a decade, but it wasn’t until 2019 when the brand rolled out its AXS concept that truly capable solutions for modern gravel became available.
AXS allowed riders to pair road components, such as Red shifters and chainsets, with MTB ones, such as Eagle rear derailleurs and cassettes, to create wide range gearing that was capable on gravel terrain.
‘We recognised there was a niche that even those “mullet” setups couldn’t fulfil though,’ says Jason Fowler, SRAM’s drop bar drivetrain product manager. ‘Something 1x, with wider range than road but closer gear steps than our 10-52 Eagle cassettes.’
Hence XPLR was introduced in 2021. There were 2x options, but really this road-offshoot drivetrain product was about 1x gearing and its 10-44t, 12-speed cassette.
‘While there are riders better served by the mullet setup at the adventure end of the gravel spectrum or 2x at the all-road end, this type of drivetrain serves most gravel riders best,’ says Fowler. ‘Based on our research, this middle segment of the gravel market is the biggest, with around 60% of riders using it. However, we wanted new Red XPLR AXS to offer more to riders at the extremes, so we’ve introduced more range in a 10-46 cassette, but with similarly close gear steps, as it is now 13-speed.’
With the launch of Red XPLR AXS, SRAM ostensibly moves into a product category unchallenged, because neither Shimano nor Campagnolo offer a 13-speed, 1x electronic groupset.
Business up front, party out back
The Red XPLR AXS controls, callipers and rotors are carried over unchanged from the new Red AXS road family, and there have been some updates at the chainset that are covered below, but the main talking point is the new rear derailleur and cassette.
Using the UDH interface that SRAM introduced to MTB in 2019, which is now common on gravel bikes and is making its way into road as well (no prizes for guessing what happens to next-gen Red AXS’s rear derailleur), SRAM has introduced a full-mount rear derailleur to XPLR.
The design is similar in concept to SRAM’s Eagle Transmission, in that rather than attaching to a hanger that acts as an intermediary between frame and derailleur, the derailleur fixes to the frame directly, sandwiching the dropout where it accepts the rear wheel axle.
The derailleur itself is what the rear thru axle fixes into, meaning the derailleur’s position relative to the cassette becomes a known quantity, rather than a variable depending on particular hanger dimensions. As such, full-mount means there is no need for limit or B-tension adjustment.
‘Once installed, shifting is perfect from the get-go,’ says Fowler. ‘Full mount is also inherently incredibly strong, so there’s no longer any risk of mis-shifts due to hangers being bent in transit or under impact.’
Along with the general concept, Red AXS XPLR’s full-mount rear derailleur shares Eagle Transmission’s ‘Magic’ lower pulley (the centre of the pulley is essentially a large bushing and the toothed outer ring ‘floats’ on it, so if a stick gets stuck in the pulley’s center the wheel can still operate), as well as its replaceable subcomponents idea (parts of the rear can be replaced if damaged). However, the design isn’t exactly the same.
‘XPLR’s full-mount derailleur prioritises shift speed over shifting under load,’ says Fowler. ‘Meaning it shifts faster, because gravel riding requires less high-load shifting than MTB.’
Similarly, the clutch is a toned-down version of Eagle’s, to save weight and ensure no drivetrain efficiency losses. Notably, XPLR no longer uses SRAM’s Orbit fluid damper for chain management, which is found on the brand’s premium road rear derailleurs.
‘In the gravel application, the Eagle-inspired spring clutch provides better chain management,’ says Fowler.
Golden ratio
The radical rear derailleur is paired to an equally interesting cassette. The 10-46 block, as it is 13-speed, has one-tooth jumps between the four smallest sprockets despite providing 460% range.
‘The sprocket progression allows fine cadence control at higher speeds but meaningful jumps when easier gears are needed,’ says Fowler.
Due to a heavily machined-out construction and the largest 3 sprockets being made from aluminium, SRAM says it weighs only 288g as well, which is nearly 100g lighter than the previous generations 10-44t design, despite offering an extra gear and more range. In fact, weight loss is a theme throughout the new design, with SRAM saying in comparable setups new Red XPLR AXS is 218 lighter than before (2,706g versus 2,488g). SRAM says this makes the groupset the lightest gravel offering on the market.
In a win for cross-compatibility, the new cassette fits within existing XDr freehub body dimensions, meaning SRAM’s existing Flattop 12-speed road chain can be used with the groupset.
‘The full mount interface frees up a little space on the outboard side of the cassette, and the 46t sprocket is dished out over towards the rear wheel’s spokes a touch, so we’ve been able to fit 13-sprockets in with the spacing of 12-speed,’ says Fowler.
All sewn up
At the front of the drivetrain, while XPLR uses identical cranks to the new Red AXS road groupset, this new gravel version again follows Eagle’s lead with Thread Mount chainrings. The chainrings attach to the crankset spider via a threaded interface, meaning they can be easily swapped.
As XPLR is offered with a spider-mounted power meter (accurate to +/-1.5%), the Thread Mount design lets the user replace chainrings without unnecessarily replacing the power meter along with them, which has been a criticism of the brand’s road crankset since the one-piece design was introduced in 2019. Chainrings are available in sizes from 38t-46t.
Elsewhere, new Red XPLR AXS is business as usual as per the latest road-going Red AXS design, being designed to work with Hammerhead’s new Karoo head unit and AXS inter-compatibility.
- For more information on the new SRAM Red XPLR AXS, visit sram.com
SRAM Red AXS XPLR weights and pricing
New SRAM Red AXS XPLR is available in several guises. It is offered on stock builds from the following manufacturers:
The groupset can be bought aftermarket too. Base price is £3,530 / €3,960 / $3,529, but that doesn’t include a Hammerhead Karoo 3 computer or power meter. Price for the power equipped version is £3,980 / €4,465 / $3,979. Hammerhead Karoo is priced at £450.
Claimed weights for individual components of the groupset in both PM and non-PM equipped guises, versus previous generation Red eTap AXS XPLR and Force XPLR AXS, are as follows:
The post New SRAM Red XPLR AXS is 13-speed and uses an Eagle Transmission-esque full-mount rear derailleur appeared first on Cyclist.