In recent times, Unbound has turn out to be the world’s greatest and most prestigious gravel race. Together with launching rider careers, it has additionally turn out to be a testing and proving floor for the newest cutting-edge gravel tech. For the eagle-eyed amongst us, there is a good probability you might spot one thing new or unreleased. At this 12 months’s occasion, I acquired fortunate early on when, on a shake-out trip, I noticed one thing new aboard the bikes of professional riders Haley Smith, Keegan Swenson and Russel Finsterwald, amongst others.
What at first look regarded like a SRAM mullet construct, which incorporates a 12-speed mountain bike transmission rear derailleur, was, in truth, a brand new gravel drivetrain altogether. A more in-depth have a look at the UDH-mounted derailleur, the variety of rings on the cassette, and the tooth on the largest cog confirmed it: this was the unreleased 13-speed SRAM Purple XPLR AXS we would heard rumours about.
At present, with the official launch of the SRAM Purple XPLR AXS merchandise, we’re lastly capable of dive into the weeds of this top-tier gravel racing drivetrain, and there is lots to speak about.
I am going to provide you with an outline of what is new, the way it rides and whether or not I am able to put my current bike available on the market so I can swap over to this new UDH-only groupset.
Introducing: SRAM’s 13-speed Purple XPLR AXS gravel drivetrain
(Picture credit score: Anne-Marije Rook)
Purple XPLR AXS is SRAM’s most superior digital and wi-fi gravel groupset but. Weighing simply 2,476 grams with an influence meter (2,398g with out), it is the lightest gravel groupset SRAM has ever produced, whereas additionally being strong and including a thirteenth cog. It additionally options SRAM’s finest brake callipers and controls but, however the hanger-less interface comes with its personal set of advantages…and disadvantages.
SRAM’s 13-speed Purple XPLR AXS groupset: what’s new
(Picture credit score: Anne-Marije Rook)
13 speeds
That is SRAM’s first 13-speed velocity drivetrain. Whereas Campagnolo was the primary to supply a 13-speed, superlight gravel groupset, the Ekar groupset is, as of but, mechanical solely.
Gear vary
The XPLR cassette now goes as much as a 46t, in comparison with the earlier 44t, for a gear vary of 460%.
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The XG-1391 XPLR E1 13-speed cassette has the next gear development: 10, 11, 12, 13, 15, 17, 19, 21, 24, 28, 32, 38, and 46. Notice that solely the 12 and 46 are new.
For comparability, the prevailing 10-44t XPLR cassette affords a 440% vary and the next cogs: 10, 11, 13, 15, 17, 19, 21, 24, 28, 32, 38, 44.
The Eagle cassette, well-liked with these wanting the largest (climbing) gears, affords a 500% vary with the next gear jumps: 10, 12, 14, 16, 18, 21, 24, 28, 32, 36, 42, 50
The cassette stays XDR suitable.
(Picture credit score: Anne-Marije Rook)
Weight reductions
The brand new groupset is at the least 100 grams lighter than its predecessor and even lighter than the brand new SRAM Purple AXS street groupset.
Hanger-less, UDH-only rear derailleur
Taken from the world of mountain biking, the Full Mount derailleur is connected on to each side of the rear dropout to create a rock-solid connection and get rid of derailleur hangers altogether. Due to the exact alignment of the derailleur and the cassette, restrict screws and B-link adjustment are not wanted both. Whether or not knocked about in journey or crashed throughout a race, the derailleur will proceed to carry out and even sports activities a neat reset perform. Extra on that under.
There’s additionally an MTB-inspired clutch spring for superior chain administration and retention.
(Picture credit score: Anne-Marije Rook)
An influence meter with replaceable chainrings
Up till now, some SRAM Purple energy meters had a significant disadvantage: totally built-in chainrings. Designed to acquire the bottom attainable weight and the very best degree of accuracy, the entire unit must be changed every time the rings put on out. You can also’t simply swap chainrings for most popular gear ratios on completely different terrains. The brand new Purple XPLR AXS 1x Energy Meter fortunately comes with a spider-based energy meter with detachable and replaceable Thread Mount chainrings. The 1x aero energy meter, nonetheless, nonetheless has a completely built-in ring.
(Picture credit score: Anne-Marije Rook)
SRAM’s 13-speed Purple XPLR AXS groupset: what’s not new
(Picture credit score: Anne-Marije Rook)
Sure parts had been carried over from current product strains, together with:
Brake calipers and shift-brake levers
I used to be very excited to see that the brand new brake calipers and shift-brake levers from the lately launched Purple AXS street groupset had been carried over to this groupset. These of us right here at Biking Weekly who’ve had the pleasure of utilizing all of them agree: they’re merely unbelievable.
The shift-brake controls and hoods underwent a complete aesthetic and ergonomic redesign, full with the repositioning of the hydraulic brake grasp cylinder, improved hood angle, and the addition of hood-based bonus buttons. Lean and elongated, the highest of the hoods are about half as tall as its predecessors – a most welcomed change.
The brake callipers function a lighter, totally aluminium physique and inside, the pistons had been repositioned additional up within the caliper physique to permit power to be utilized nearer the sting of the rotor.
(Picture credit score: Anne-Marije Rook)
Magic Wheel
Taken from the Eagle Transmission mountain bike line, the Magic Wheel is an outsized decrease pulley wheel product of two components. These two components are designed to spin collectively except one thing lodges within the interior a part of the pulley wheel. At this level, the outer a part of the pulley wheel will proceed to spin even when the center half is clogged up with dust otherwise you’ve caught a stick.
The way it carried out
(Picture credit score: Anne-Marije Rook)
“Carry on the sticks, stones, and airport baggage abuse. The Purple XPLR AXS rear derailleur will fortunately take all of it,” SRAM boasts in its advertising copy. And I positive took that to coronary heart when the primary lengthy outing on my take a look at bike rapidly became a Sort 2 trip. You recognize the sort—one the place you get your each day step rely in and return trying like your shins had picked a struggle with a feral cat.
Simply 10 miles into the trip, I managed to get a stick caught in my derailleur and the shifting was wonky for the rest of the day. A lot for these claims, I believed till I found the derailleur’s very neat influence reset perform.
Taken from the SRAM Eagle Transmission, the Purple XPLR AXS derailleur mount is designed to rotate within the occasion of influence, transferring your derailleur away from hazard. It might then be reset to the proper place after influence. To do that, you may have to first examine to see if the derailleur has certainly rotated. There are hash marks on the again of the derailleur, particularly on the knurled ring and the Full Mount. If these should not aligned, then a reset is required. To take action, you merely loosen your rear thru-axle by 1 / 4 to half flip and the derailleur will snap again into place. Retighten the thru-axle, and off you go. Fairly cool.
(Picture credit score: Anne-Marije Rook)
As soon as working because it ought to, the shifting impressed with its crispness and reliability. It feels splendidly easy, even to get throughout the largest hole between the 38t and 46t.
I do know shifting on SRAM’s Transmission groupset obtained blended evaluations, with some lamenting the gradual speeds. Fortuitously, the Purple XPLR AXS performs with ample velocity, although I’ll observe that the multishift down the cassette carried out faster and higher than the multishift up the cassette, which struggled with the larger rings.
After my preliminary stick encounter, no quantity of rocky gravel or rooty singletrack managed to upset the derailleur’s efficiency and the MTB-inspired clutch ensured the chain stayed taught, at all times.
(Picture credit score: Anne-Marije Rook)
The tight gear jumps on the cassette are very nice. With this new 13-speed cassette, SRAM aimed to present customers “the climbing gears you crave on gravel and the tight jumps you want on spicy sprints.” What it is created is a cassette that falls someplace between the prevailing 12-speed 10-44t XPLR cassette and 10-50t Eagle cassette. It is acquired 20% extra vary than its 12-speed sibling and 40% much less vary than its mountain bike cousin. The one actual change over the prevailing cassette is the addition of a 12t cog and the alternative of the 44t with a 46t cog.
Solely the decrease finish of the cassette will get improved gear jumps. On the other finish, the hole really grew from the prevailing 38t to 44t to now a 38t to 46t leap. With that stated, the tight development on the decrease finish of the cassette is noticeable and, certainly, good to have on quick, flat terrain and on pavement. Personally, my gravel rides are usually fairly hilly and tough, and thus, I spend most of my time properly above the 13t cog on the cassette. To that finish, the largest 46t is a welcomed alternative.
(Picture credit score: Anne-Marije Rook)
As talked about above, the brand new drivetrain is paired with the brake callipers and shift-brake levers taken from the most recent Purple AXS street groupset, which is an effective factor. Between the totally redesigned hoods, levers and the calipers themselves, SRAM may have created one of the best brakes on the street and gravel market. Not solely are the hoods very comfy, however the highly effective brakes really enable for single-finger braking.
I am a giant fan of the bonus buttons as properly. Whereas the buttons are fairly small, the situation of the within of the elongated hoods, simply above the thumbs, works properly. Just like the blips, you possibly can assign the button’s perform, be it managing your dropper put up, shifting gears or scrolling by means of the pages of your pc. I take advantage of them for shifting, as they work very well should you have a tendency to spend so much of time on prime of the hoods fairly than within the drops.
UDH Compatibility Conundrum
(Picture credit score: SRAM)
The brand new drivetrain is barely suitable with frames which have a UDH (Common Derailleur Hanger) interface. This expertise was launched by SRAM in 2019, initially geared toward eliminating frame-specific rear derailleur hangers in mountain bikes whereas additionally standardizing the place of the derailleur with the cassette for higher and extra constant shifting efficiency. The system integrates the derailleur hanger into the body dropout across the axle.
SRAM’s Full Mount derailleurs make use of the UDH interface however do not contain an precise hanger. A Full Mount derailleur attaches straight onto the body, on both facet of the dropout. Because the Full Mount launched in 2023, the system has garnered beneficial evaluations for its robustness and ease. Nonetheless, up till now, the UDH and Full Mount expertise was largely thought-about a mountain bike factor. However gravel actually stands to achieve from its advantages, like improved robustness, shifting efficiency over tough terrain, and chain retention.
Fortunately, the adoption fee of UDH is rising amongst body producers, and types like Trek, Specialised, Canyon, Lauf, Cervelo and 3T already provide some gravel bike fashions with a UDH interface. Nonetheless, there is not any method to convert an current non-UDH body to turn out to be UDH or Full Mount suitable – at the least, not in a manner SRAM will acknowledge. Some aftermarket conversion kits may be discovered on the web however SRAM says it would void any guarantee if these merchandise are used.
For customers, which means that if you wish to improve to this groupset, your present bike should already sport a UDH interface, otherwise you’ll have to purchase a brand new body.
For body producers, the Full Mount expertise might create a little bit of a conundrum as SRAM is principally saying, ‘conform or be disregarded.’
Shimano and Campagnolo haven’t (but) totally embraced UDH expertise. Whereas suitable when used with the precise components, it isn’t all simple. For instance, Shimano and Campagnolo’s Direct Mount derailleurs not embody a linkage between the derailleur itself and a traditional derailleur hanger. Shimano claims this creates a extra exact derailleur alignment—not not like the UDH raison d’être. Nonetheless, except you purchase a selected Direct Mount suitable UDH hanger, you may have to put the B-Hyperlink again in, thereby negating any advantages.
This sparks numerous questions:
- Are non-UDH frames quickly going to go the way in which of the rim brake?
- Will body producers conform to UDH or will we see allegiances shaped between bike and element producers?
- Is SRAM forcing Shimano and Campagnolo’s hand?
As for the solutions, we’ll have to attend and see.
Pricing
(Picture credit score: Anne-Marije Rook)
The head of SRAM’s gravel product line comes with a premium price ticket. The groupset with energy meter retails for $3,979 / £3,980. With out the facility meter, it prices $3,529 / £3,530
With bikes costing a fortune today, I not get a lot of a sticker shock after I see these costs come by means of. Nonetheless, what made me do a double-take on this groupset particularly, is the elevated price of wear and tear components. The cassette alone is $650 / £600 and no alternate choice is out there as of but. That is $400 greater than the present top-end XPLR cassette and at the least $200 greater than an Eagle cassette. The flattop chain, too, has gone up $89-99 versus the present flattop Purple chain at $75. Fortunately, the brand new groupset is backwards suitable with all flat-top chains.
For groupset comparability, Shimano’s top-end gravel groupset, the 2×12 GRX Di2 with out energy meter, prices round $2,533/£2,100. It affords a 506% gear vary (when constructed with an HG710 11-36t cassette) and weighs 2,747 grams with out a energy meter. Is the additional grand well worth the thirteenth cog, 349 grams of weight-savings and hanger-free derailleur?
Verdict
(Picture credit score: Anne-Marije Rook)
Extremely light-weight, bombproof, best-in-class braking, and extra gears: there’s a lot to love in regards to the new Purple XPLR AXS groupset. However is it sufficient to persuade me to place my non-UDH bike available on the market proper now with a view to swap over to this UDH-requiring groupset? If I had been a severe biker racer, yeah possibly.
The hanger-less Full Mount derailleur actually is an asset, not solely due to its crisp and dependable shifting efficiency but additionally due to its robustness. Placing a motorcycle on a aircraft to journey to occasions is at all times a threat. You by no means fairly know what state your bike goes to be in on the opposite finish. The Full Mount rear derailleur can actually take a beating – throughout journey and on the race course. A few additional tooth on the higher finish of the gear vary are at all times welcome, each with a view to conquer climbs and for the choice to run an even bigger chainring within the entrance. And the gradual gear jumps within the lower-end of the cassette shall be an asset in race tempo and end dash.
As a non-racer on the extra adventure-y finish of the gravel spectrum, I’m not the focused demographic for this groupset. It is made for many who have to get probably the most out of their bikes. Lachlan Morton gained this 12 months’s 200-mile Unbound Gravel race with a median velocity of 22mph. The ladies’s race completed in a nine-person dash end. In gravel racing, each watt, each minute, each gear counts. Whereas the 12t sprocket and weight discount is a mere nice-to-have for a rider like me, it may be a must have in racing.
With that stated, the robustness and shifting efficiency of the Full Mount rear derailleur are attracts, and I am sure we are going to see extra of this expertise in future releases. Thus, upgrading to a body with UDH will not be a foul concept typically.
Greater than something, what I want my present XPLR groupset had from this launch are the shift-brake levers and brake callipers. And there, we’re in luck. The shift-brake controls are backwards suitable with all AXS teams, thus one can merely improve these parts with out having to acquire a brand new body.
What I’ve realized in my 11 years within the business is that SRAM does trickledown expertise very, very properly and so one factor’s for sure: my non-UDH bike’s days are numbered.
