A new 13-speed SRAM Red XPLR AXS groupset has been spotted at the 2024 Unbound gravel race.When SRAM recently launched its flagship Red AXS groupset, a gravel variant was curiously omitted.Now Red XPLR AXS is here and its a radically different product from its road counterpart.We spotted the groupset on Tiffany Cromwell's Canyon Grail. - Sam Andrews / Our MediaThe new gravel groupset borrows from SRAMs Transmission (what SRAM is officially referring to these components as, after initially being called T-Type) mountain bike groupsets, with the derailleur hanger incorporated into the rear derailleur itself, mounting directly onto a SRAM UDH (Universal Derailleur Hanger) dropout.There are also some interesting features we didnt expect, which may give a hint about how SRAMs road and gravel groupsets will develop in the future.Lets take a look at the components.A direct-mount rear derailleurThe very dusty new rear derailleur. - Sam Andrews / Our MediaThe new rear derailleur confirms its a Red XPLR AXS model because it says so on the component theres a Red graphic on the main body and an XPLR graphic on the derailleur cage by the lower pulley wheel.Like Red AXS, the Red XPLR AXS rear derailleur features handsome polished sections and appears to be equipped with ceramic bearings.The Red AXS rear derailleur relies on an Orbit Fluid damper, but the new derailleur appears to borrow the Overload clutch found on Transmission rear derailleurs.The Overload clutch is focused more on protecting the derailleurs shift motor to better protect the derailleur from damage.The road Red AXS rear derailleur relies on an Orbit Fluid damper. - Russell Burton / Our MediaUnlike the new Red AXS rear derailleur, which relies on a conventional derailleur hanger, this Red XPLR AXS derailleur mounts directly to the frames dropout.This means the derailleur forgoes a conventional rear derailleur hanger and instead uses SRAMs UDH standard.Because of the UDH dropout, T-Type Transmission rear derailleurs lack limit and B-tension adjustment screws because the distance between the derailleur and cassette is controlled.Instead, the derailleur is set up using SRAMs AXS smartphone app or via buttons on the derailleur itself.The Transmission rear derailleur lacks limit and B-tension screws. - Steve Behr / Our MediaAs a result of the rear derailleur lacking limit and B-tension screws, like Transmission, we suspect there will likely only be one cassette option.In terms of ratios, the new 13-speed XPLR cassette could be a 10-48t, which would match Campagnolo Ekar GT currently the widest-ranging gravel cassette offered by any of the Big Three groupset manufacturers.Campagnolo can say it offers the widest-ranging gravel cassette. - Oscar Huckle / Our MediaBy comparison, SRAMs Transmission rear derailleurs are designed around a single 10-52t cassette. The road-oriented SRAM Red AXS rear derailleur can handle up to a largest 36t cog.Mountain bike uptake of the SRAM UDH dropout has been rapid and while its becoming more widespread on gravel bikes, there are many key models omitting the standard.On the basis of this rear derailleur relying on the standard, surely most, if not all new gravel bike releases are going to adopt the UDH standard, especially because the standard also plays nicely with competitors' rear derailleurs.Shared shifters and brakesThe groupset seems to use the existing Red AXS shifters, as seen on Keegan Swenson's Santa Cruz Stigmata. - Brett Rothmeyer / Keegan SwensonLaunched only a couple of weeks ago, SRAM Red AXS is the brands latest flagship road bike groupset, shaving 154g from its previous generation.SRAM Red AXS incorporates a new lever and hood design, improved braking performance and design, and faster front shifting. Other than the price, senior technical editor Warren Rossiter found little to fault in his review.From what we can deduce, SRAM Red AXS XPLR shares many of the same components as Red AXS. The shifters, brake calipers and disc brake rotors appear to be identical.The shifter's new hood shape is much lower in profile compared to the previous generation and 7mm longer in reach, too. The hydraulic piston has also been reoriented from its previous vertical alignment to a new horizontal layout to improve braking performance.CranksetThis crankset looks to be a carry-over with updated 'SRAM' graphics on the crankarm. - Sam Andrews / Our MediaThe new crankset appears to be 1x only and the teeth are presumably oriented to mesh nicely with the chain.Over the weekend at Unbound, weve seen a few riders using different crankset setups Keegan Swensons Santa Cruz Stigmata had a 1x aero chainring with an integrated power meter, for example, while others were using the existing, 12-speed Red 1 crankset with a non-integrated power meter.This suggests there may be some backwards compatibility between the new 13-speed components and existing 12-speed chainrings.Wed nevertheless expect SRAM to release a new crankset with updated graphics and tooth profiles, though, as every new groupset needs a crankset, after all.Chain and cassette a sign of the future?The fact Red XPLR AXS is 13-speed will almost certainly result in some product incompatibilities. - Brett Rothmeyer / Keegan SwensonOne of the most exciting aspects of SRAMs latest Red AXS road groupset is its backwards compatibility. This means if you own a SRAM Apex, Rival or Force AXS groupset, you can upgrade to the new Red one piece at a time.However, that doesnt seem to be the case with SRAM Red AXS XPLR. Why? Because its 13-speed.If you count the cassette cogs, there are 13 teeth. This is paired with a new 13-speed chain.The shifters, brakes and crankset may be borrowed from SRAMs flagship, 12-speed road groupset, but to upgrade here youll likely at least need the new Red XPLR AXS rear derailleur, cassette and chain.Riders have enjoyed being able to mix and match components for a while now. - Jack Luke / Our MediaPreviously, all of SRAMs performance-oriented road, gravel and mountain bike groupsets were 12-speed. This means they were all cross-compatible with one another, meaning, for example, you could pair road bike shifters with a mountain bike drivetrain.It makes sense for SRAM to go to 13-speed because, until now, this has been a key selling point for one of its main rivals, Campagnolo. Both its Ekar and Ekar GT groupsets are 13-speed and the extra cog enables a more progressive jump between gears.However, the downside is this means SRAM Red AXS XPLR will introduce more component incompatibilities for example, you wouldnt be able to use a Transmission 10-52t cassette with the new rear derailleur if you wanted a wider gear ratio because its 12-speed.This could mean a wholesale move to 13-speed groupsets is coming from SRAM in the future. However, T-Type Transmission is only the best part of a year old (and the new 12-speed Red AXS is just under three weeks old) and it wouldnt make sense for SRAM to supersede a product so soon into its lifecycle.When will SRAM Red AXS XPLR be released?The new Red XPLR AXS and XX SL Transmission groupsets being raced side-by-side. - Unbound / Taylor ChaseThe groupset looks to be a final production unit rather than a prototype because of the production graphics, so a launch may not be too far away.However, it appears to be one of the first times the groupset has been used out in the wild and there may be a period of SRAM gathering feedback from its sponsored professional riders, to check the performance stands up to real-world use.Weve asked SRAM to comment and will update this article when we receive a response.