SRAM t-type transmission_d_merdano_2.header

SRAM Transmission drivetrain and Code Stealth Brakes

Photos Deniz Merdano
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Normally after a new product's presentation, and maybe a first ride, I take some time to formulate my thoughts, to let the Kool-Aid ooze out of my system. Occasionally, as in this case, something comes along that moves the needle a little more than say, the new iPhone and my frothing can't be contained.

While this new system includes AXS wireless shifting, that feature is not what makes it newsworthy. If you glance again at the image above, that is my foot being held up by the mounting support on what replaces the hanger bolt area of a traditional derailleur. It held my weight entirely* and afterwards, without any intervention at all, it shifted perfectly. I was told this is child's play for this device and that it has been tested to withstand approximately 3 times my 170-odd lbs (77 kg).

*In the image it may appear that part of my weight was being supported by the seat stay but when zoomed in, a clear gap between my heel and the frame is visible

That part of the mechanism is where all the electronics and servos live, shielded from harm the way the survival shell protects F1 drivers during a crash. Obviously, this doesn't mean a T-Type derailleur can't be broken, but it appears to be vastly burlier than any derailleur that has come before, thanks largely to the absence of the tiny replaceable hanger but also because of its triangulated mount on the rear axle.

axs t-type launch 2

This is the XO trim level of the T-Type "Transmission." SRAM doesn't think drivetrain is an accurate label for the duties T-Type performs. The derailleur here has been taken apart to demonstrate the replaceable components.

Eagle T-Type Coles/Cliffs Notes

Beyond the strength of the system, further bolstered by SRAM's overload clutch (which almost instantaneously disengages the motor in the event of an impact, allowing it to move away from the blow freely, thus protecting the servos), there are several other noteworthy features of T-type which is currently available in three trims: XX SL, XX, and XO.

  • No limit or b-tension screws - because of the accuracy of the "Full Mount" interface, the derailleur knows exactly where the cassette is and generally shifts perfectly as soon as it is installed - although some micro-adjustments may be required.
  • "Full X-Sync" - T-Type can shift under full power going up or down the cassette. In fact, it shifts better under power (and not so great on the repair stand). This is accomplished with a complex system of ramps, cutouts, and periodic application of narrow-wide teeth, particularly on the largest cogs.
  • Built for the long haul - components that are subject to impacts and wear are easily replaceable and disassembly requires only two hex keys. The cage is actually removable without tools and is also available as a replacement part.
  • T-type cassettes have more balanced steps between cogs. 10-12–14-16-18-21-24-28-32-38-44-52 (Non T-type ratios are 10-12-14-16-18-21-24-28-32-36-42-52).
SRAM t-type transmission d merdano 5

SRAM's Universal Derailleur Hanger (UDH) program was an elaborate ploy to prepare the world for a system that would eliminate the hanger altogether.

Some of you may be surprised to learn there was a time before replaceable derailleur hangers; the hanger was part of your rear dropout that was welded or brazed to your frame. At first, they worked reasonably well. If the hanger on your steel frame became bent, it could be bent back into its original alignment with a tool. With steel, this could even be done multiple times before the hanger broke. If it broke, a new one could be welded or brazed in its place. Heat-treated aluminum frames changed all that and if your hanger survived the original impact, the brittle material usually broke during any alignment attempt, and your frame was either a single speed or garbage. And the replaceable hanger was born, which was an inevitable solution for carbon frames as well.

The earliest patent for replaceable hangers was filed by Cannondale in 1989 but they began appearing earlier in the 1980s, and they were usually made of cheese. For many years it made sense to pack one along with you for every ride. Despite becoming much stronger in recent years, this just meant your much-more-expensive derailleur would break and bend more often, so the hanger remained the weakest link, even after it got stronger.


Given the spindly parallelogram architecture we inherited from Tulio Campagnolo*, (who also invented the two-handle corkscrew we are all familiar with and the quick release) a new approach was needed to make the system burly enough to handle the demands of mountain biking. The first step, by SRAM's estimation, was to eliminate the hanger altogether.

This wasn't how the whole story began, however. Apparently, SRAM's German engineers were frustrated by the real world performance of their Eagle drivetrains, particularly when ridden by your average consumer. Alignment and adjustment issues meant riders were not experiencing the dreamy, trouble-free performance they envisioned; cable tension was inconsistent in non-AXS systems, limit screws and the finicky b-tension adjustment were often neglected, and even if the frame happened to precisely suspend the hanger, it was likely that either the mech or the hanger (or both) was bent enough to screw up performance. Apparently, German engineers like control, and these factors were beyond theirs.

*While not credited as the first person to invent a system to move the chain between cogs, Campagnolo's 1949 Gran Sport, a twin cable affair, is often acknowledged as the first modern derailleur

SRAM t-type transmission d merdano 3

The derailleur clamps the split pivot of the Trek Fuel EX-E with 35 nm of torque. I haven't removed the shock to confirm this has no impact on the free movement of the pivot, but I haven't noticed any performance impact when compared to the previous (UDH) mounting with a hanger.

Clearly a lightbulb went off with one member of the team who realized a system that could eliminate user error and neglect could be designed, and make the derailleur as immune as possible to the injuries these dangling pulley holders regularly sustain. Rather than mounting the derailleur to the frame, or worse, to the hanger which is then mounted to the frame, what if the derailleur was mounted to the rear axle, on both sides of the dropout of course, with no hanger at all?

The T-type system mounts the derailleur directly to the rear axle with a yoke that cradles the rear dropout, adding strength through triangulation, so the system is no longer dependent on the strength of a hanger or your frame. This also ensures your derailleur is perfectly in line with your cassette since both revolve around the 12 mm aluminum rear axle.

sram t-type rear derailleur

A detailed view of the SRAM T-Type rear derailleur and frame interface.

The Most Noble Bait and Switch?

SRAM’s “UDH” program can, in retrospect, be seen as benevolent corporate subterfuge. In order for the T-type system to get the serious foothold it would require, as soon as it was released, the company’s universal derailleur hanger would need solid market saturation beforehand. This means product managers at companies like Trek, Specialized and even Forbidden, would have to be sold on the project years before, so UDH design integration could precede the arrival of the T-type system.

What that means is, all of those UD hangers were simply placeholders for a system that completely does away with the derailleur hanger. It‘s a brilliant strategy that would be seen as devious, were it not for the goal of making derailleurs robust and virtually impervious to the degradation in performance every hanger-based derailleur with three set screws is prone to. Even AXS.

SRAM t-type transmission d merdano 8

I vastly prefer the new pods to the old controller, at least to manipulate the rear derailleur. The Ultimate version has two toggles to choose from; one is convex and the other concave. I decided on one of each (convex up top) to more easily distinguish the two. There is ample adjustability to meet my needs.

Eagle AXS: So Last Week

At first, it seemed insane that SRAM would be revolutionizing the derailleur so soon after, well, revolutionizing the derailleur. Before I saw the system or knew anything about it, but after I became aware it was drivetrain-related, I wondered if this was something else entirely; a system to capitalize on the largesse of an increasingly well-heeled mountain biking clientele.

When SRAM introduced XX1, which by their own reckoning sat higher than a Shimano XTR-equivalent, it was expected to be a niche product with a limited market. Instead, It blew their forecasts away and became unexpectedly successful. This knowledge had me worried that this was simply going to be a fancier and more expensive AXS system with more carbon, aluminum, and titanium added; more bells and more whistles, and perhaps personalized engraving on each component. Or each chain link. It‘s likely something that, situated above the original XX1 AXS ‘luxury group,’ would have produced high margins and lots of sales, like most luxury goods, but without adding much utility, value, or performance for any rider from average to elite.

Thanks for not doing that, SRAM.

While this is certainly an expensive system, with even pricier options like power meter cranks, the emphasis on longevity, strength, easily replaceable wear elements, accuracy, and repeatable performance for any user, makes this horse pill a little easier to swallow. Unless of course you recently laid down your hard-earned shekels for the existing AXS system, which will feel like choking down a porcupine.

SRAM t-type transmission d merdano 17

The clamp that mounts directly to the bar, rather than this direct mount version, can be switched right to left because it can be flipped over and because the diameter of the Pods is 22.2, just like your bar. I haven't checked if the direct mount version is reversible, but it appears that it should be.

When I first wrote this I hadn’t yet seen any retail prices and when I asked Chris Mandell about the gap between this group and the already very expensive AXS group, he said simply; “I think you’ll be pleasantly surprised.”

Currently, the XX1 AXS rear derailleur, listed on, sells for 753 USD. The T-type AXS XX rear derailleur, as listed in my press materials, costs 650 USD, both without a battery.

A factor that makes me cautiously optimistic about the opportunity this system could present for average riders, is the possibility of other companies figuring out how to use this tech to offer their own hanger-less solutions. SRAM could have made it difficult for other companies to make components for their XD driver, but that didn‘t happen to my knowledge. I was even told there were no objections to Shimano using it.* They have been more prickly about others using their narrow-wide chain and chainring standard, at least when the SRAM tooth shapes were mimicked, and there are likely legal battles being waged behind the scenes about other intellectual property as we speak since lawyers gotta lawyer, but let's lean into the signs of generosity. For the benefits of T-Type to be spread more widely, keeping that patent open (or open enough) could be a huge benefit for average Joe and Josée riders everywhere and a sign that SRAM is that rare multi-national that considers more than simply the bottom line.

*SRAM would of course be aware that Shimano avoids piggybacking on their tech at all costs

axs t-type launch 1

Complex shapes that have nothing to do with grandpa's drunken whittling. The T-Type cassette has a much more involved system of ramps and cutouts than previous Eagle versions. The indents you see punch through to the inside of the tooth to hold the wide portions of the chain in place, so the shift happens in precise, predetermined locations. This allows the chain to only climb or descend along the cassette where it will be supported, and remain in contact with the cogs, as it derails. Photos - Cam McRae

axs t-type launch 7

The existing Eagle cassette seems much more conventional in comparison.

A counterpoint to this could be that SRAM is planning a cable-actuated trickle-down themselves, serving many of the benefits of the hanger-less system, at a much more modest price. Chris Mandell gave me no indication one way or another about this when I asked him directly. For such a jovial fellow, his poker face is surprisingly impenetrable.

My guess is that it would take an engineer with derailleur experience to determine the viability of operating this system with springs and a cable, rather than servos and wireless transmitters while producing many of the same benefits.

SRAM t-type transmission d merdano 12

When removing or reinstalling the rear wheel, the 21t cog should be used (usually) as opposed to every other derailleur I've used which has always called for the smallest cog.

SRAM t-type transmission d merdano 15

The red plastic element you see serves as an indicator for the 21t (gear 6) setup cog for most frames but this is actually bike-dependant and some frames require the 24t (gear 7) cog. This information will be listed on SRAM's website.

Shifting Under Full Power

The T-Type cassette is an engineering marvel. Spaced at carefully determined intervals, the largest three cogs consisted of narrow-wide elements to keep the chain from dropping down or shifting up from those locations. What is remarkable about this is that the chain must find the correct spacing or it won't sit down at all. While I did have a skipping issue at one point when the micro adjustment wasn't bang on, I never had the chain misfire and fail to mate with the cogs once it was properly set up. Even smaller cogs have a few narrow-wide elements and the entire cassette performs a delicate dance of catch and release so that it feels like the chain never loses purchase, even in situations where you'd normally never dream of shifting. And, as I mentioned earlier, the system thrives under weight and it actually shifts better when more power is applied.

The feel is slightly different when shifting under load compared to Shimano's current drivetrains, which have a slightly lighter-feeling action, at least when things go well, but T-Type seems more tolerant of pedal mashing and works just as well shifting up or down. It generally feels like rather than derailing and having to mesh again, your chain simply glides up or down the cogs.

SRAM t-type transmission d merdano 6

The outside of derailleur interface is quite low profile despite it's strength.


To be entirely clear, I'm glad we have SRAM trying to wade through the sticky muck of mountain bikers' inheritance. We've been trying to shake our roadie pedigree from the beginning, and in retrospect, the industry has been far too slow to make that break. The traditional rear derailleur is a perfectly adequate solution for an environment without rocks, roots, slabs, jumps, berms and dirt. Unfortunately, until this point, it hasn't been adequately up to the task of mountain biking, and it's taken until 2023 for one of the major players to address these inadequacies with anything more than incremental improvements applied to a flawed system.

T-Type seems to be a Great Leap Forward for the sorts of mountain biking that could involve your bicycle cartwheeling off a cliff, catapulting into a large rock, getting snarled in overgrown salal, or countless other unpredictable mishaps that will render the traditional rear derailleur as useful and valuable as a crushed beer can. The ability to have faith in your derailleur is no small improvement. One that also shifts in virtually any situation is massive as well.

axs t-type launch 4

I stripped down the XX T-Type derailleur at home without issue in just a couple of minutes. I removed the pulley to detach the derailleur from the chain because I don't have any spare T-Type quick links and re-using them (as with existing quick links) is not recommended. The cage will be available as a replacement part and the three versions are interchangeable. The same is true for the removed 'skid plates' shown below the cage.

And yet there is a little access issue to this AXS system, and it involves cranks and chain and cassette, and to be fair, the crank issue is likely a rare case since frames with UDH are yet to be common, but... With the previous AXS system, everything was compatible with any Eagle component, which allowed SRAM to sell an AXS upgrade system with a controller, derailleur, battery and charger only. It wasn't cheap, but you can currently find the GX version, which works identically to the more expensive variants, for under 650 USD (905 USD msrp). This inter-compatibility does not apply to T-Type unfortunately, even in one area where it could.

SRAM t-type transmission d merdano 7

These are eMTB T-Type specific cranks but the chainring (for the moment) is the existing Eagle version.

One question I had was whether you could mate a T-Type chain and cassette with an existing Eagle rear derailleur and shifter. Because the cassette mounts 2.5mm outboard of a conventional Eagle cassette, I was told they could not mate. In particular, even if your frame was UDH compatible, there won't even be clearance for the cassette apparently, and the derailleur likely won't be able to adjust outboard enough to hit every cog. It's possible this could be done with a UDH frame using a conventional Eagle derailleur, or maybe even (drum roll please) Shimano, but I haven't tried anything yet. I'm happy to say this doesn't seem to be a case of planned or forced obsolescence.

In terms of crank compatibility, I haven't actually seen the new 8-bolt direct mount interface in person but I'm aware that current chainrings won't fit the new cranks and vice versa. And yet chainrings are chainrings and it seems SRAM could have made some for T-Type that fit existing 3-bolt SRAM DUB cranks. And actually, existing SRAM X-Sync 2 rings will work relatively well. I know this because I have been using one since the T-Type version wasn't available for the eMTB application on the Trek Fuel EX-E I've been testing (which was the only UDH bike I had at my disposal to test the T-Type system). Apparently the long-term durability of the chain and cassette won't be as impressive without the new chain ring, and chain retention may be compromised as well, but for me thus far, it has been flawless.

SRAM t-type transmission d merdano 13

The flat top chain is said to improve strength and durability but much of the attraction may have been aesthetic. As SRAM puts it; "Its unique flat top design makes it the strongest change chain we have ever made. With equal importance, it upgrades the look of any super machine. These details matter."

SRAM doesn't seem to have any plans to make T-Type chainrings available for current 3-bolt SRAM Dub cranks, which means upgrading will have to include the extra 300 to 550 USD for T-Type cranks, instead of 128 USD for a new chainring The least expensive upgrade kit, the XO version, is 1600 USD, which doesn't sound bad compared to the previous GX-level upgrade kit for 905 USD or the XO1 version for 1205 USD, which lack chain, cassette, cranks, and chainring.

There is a hack to the new cranks requirement, however, and it involves eMTB cranks and the available 104 BCD chainring T-Type chainring. Finding a current 104 BCD crank may not be easy, but it's not impossible either. And you might even have one in a parts drawer.

As I said, this is not likely to be a frequent scenario. If your new bike has T-Type, it will come with the whole system. If you are buying a frame-only and already have most parts for the build, you may have to shell out for cranks. The same goes if you are upgrading your current bike to T-Type unless you want to take your chances with an existing Eagle chainring, which SRAM does not recommend, but I remain optimistic about.*

*Follow my lead at your peril #notanengineer.

sram t-type prices and weights

I have not included the power meter versions in my spreadsheet but they are available in XX trim and priced at 2299 USD / 2750 EUR / 2465. There are also eMTB versions available for Brose, Bosch, and Shimano motors as well as a 104 BCD chainring version.

SRAM Code RSC Ultimate Stealth Brakes

While these brakes look dramatically different from the cockpit, their performance thus far has been indistinguishable from the current run of Code RSC brakes, which isn't bad news. These brakes hold a bleed well, resist overheating, and have very good power and modulation. In fact, the only difference between these and previous SRAM brakes is the levers.

SRAM t-type transmission d merdano 4

A close look at my bars here will show how SRAM's Stealth brake levers make brake hoses much less obtrusive, and possibly protects them from damage as well. The calipers are unchanged mechanically.

It seems the entire design brief for these brakes involved angling the hoses towards the handlebar as they exit the levers to virtually conceal them from the rider's gaze. They do this effectively and the view is indeed very clean.

SRAM t-type transmission d merdano 11

Rather than pointing your brake lines toward the direction you are travelling in, SRAM Stealth levers push them toward your handlebar.

A nice feature for the Ultimate versions is the return of carbon levers. I care little about the few grams saved, but carbon has much lower thermal conductivity than aluminum, which means your braking fingers will be less chilly if you ever ride in frigid conditions. The only other difference I have noticed thus far is a more effectively manipulated contact adjustment dial.

DSC04609-denizmerdano  deniz merdano pano

This image shows Stealth hose routing while the image below is standard routing. Beyond the aesthetic considerations, pointing your hoses toward your bar and keeping them from dangling forward should keep them out of harm's way more effectively.

DSC03801-denizmerdano  deniz merdano cam trek fuel exe

Conventional Code levers with more loopy brake lines shown here - if you zoom in a little perhaps.

Stealth brakes come in two different models: Code and Level. There are two trim levels for both, called Ultimate and Silver. A quick way to tell the Silver from the Ultimate is to look at the caliper. The Silver caliper is black while the Ultimate caliper is, obviously, silver, with a polished aluminum finish. Both versions are forged aluminum. The names and finishes are identical for the Level models, but there are two- and four-piston versions of each for Levels while Codes are four-piston exclusively.

deniz merdano pano code stealth ultimate brakes

The power and control I have come to expect from Code RSC brakes is all there in the Code Stealth Ultimate, even on frost covered teeter-totters.

Aside from the carbon levers, and the finish, the two Codes seem identical. The Ultimate versions of both Level and Code come with titanium hardware. Code is aimed at Trail to DH while Level is prescribed for XC, although the four-piston version's copy describes, "Trail ready power in a modern XC package, for tomorrow’s races."

Code Ultimate Stealth Brakes MSRP per end: 300 USD / 360 EUR / 320 GBP

Code Silver Stealth Brakes MSRP per end: 265 USD / 320 EUR / 285 GBP

More info about Eagle T-Type and Stealth Brakes at
Cam McRae

Height - 6'/183cm (mostly legs)

Weight - 170lbs/77kg

Inseam - 33"/84cm

Ape Index - 0.986

Age - 58

Trail I've been stoked on lately - Sam's Dad's Trail

Bar Width - 760mm

Preferred Reach - 485-500mm (longer with 27.5 wheels than 29)

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+29 nothingfuture Niels van Kampenhout HughJass fartymarty imnotdanny mnihiser kcy4130 Mammal Gage Wright doodersonmcbroseph TwistedNipple Tremeer023 Velocipedestrian Andrew Major Gabriel Barbosa cornedbeef TristanC danithemechanic bushtrucker Timer Skooks Sandy James Oates 4Runner1 Zombo Metacomet lennskii Nologo Lynx . 69tr6r

Anybody look at this and think, I am super glad Shiman came out with that cheaper more durable stuff? 

This is cool and I appreciate the engineering, but I would much rather just run something cheaper that will likely last just as long and is cross compatible with existing parts.


+6 Tremeer023 Velocipedestrian TristanC Skooks lennskii Nologo

Allen, I'm with you.  I'm currently on 10Zee drivetrains on both bikes.  Once they're no longer available I'll be looking hard at the Cues range - maybe even with a few less cogs out back.

This new Eagle is cool and all but if I was looking to drop that much cash on a drive train I would be seriously looking at a gearbox bike.


+4 Andrew Major Cam McRae lennskii Nologo

I can't tell if it's a knee-jerk retrogrouch reaction, or if my coffee hasn't kicked in yet, but I feel the same way. I am a mechanical engineer, I work a stone's throw from SRAM in Germany, and I also appreciate a good challenge to conventional ideas. But this seems to be going in the "more niche and less compatible" direction, when I'd like to see it going the other way.

EDIT: now that the coffee has had time to work, I like seeing innovation like this. I still don't like the not-simple-ness of it, but that's OK. I think it is not for me, and that is also OK. It is good to have steps outside of normal design.


+1 TristanC

I am a bit unconvinced about this system, but I take issue with the fact that they haven't made a compatible chainring. Just a bridge too far. Also, the alignment of your rear axle will be critical to make this work. My final gripe is I would have concerns that this could damage your frame rather than just a hanger


+13 Niels van Kampenhout mnihiser Ryan Walters Geof Harries Mammal Znarf Velocipedestrian Todd Hellinga TristanC bushtrucker 4Runner1 lennskii Nologo

Yeah. I can understand the benefits, but I look at this vs mechanical and see avoiding the electronic drivetrain as a great way to save money to spend on other parts of the bike that are more important to me like a set of WAO wheels, or better suspension. Call it a version of Andrews Min-Max philosophy.  I guess if money was not a factor then sure, but even then, the idea of going for a ride only to find the batteries not charged just bugs me.  Given that I ride 3 or 4 different bikes depending on season, and conditions, I feel like that at some point this would happen. Coming back to the money aspect, despite hitting all the cliches (middle aged, high income earner) I balk at paying north of 10K for a bike. It’s easy to get lost in the shininess of new bike tech which is to be honest pretty cool and amazing. However, I think at some point we are well into the area of diminishing returns. I bought a near top of the line Titus Moto Lite in 2006. I think it cost me just under 6K, and it felt so ridiculously extravagant at the time. You could have spent more, but it would have to have been custom Titanium.  Now here we are and 12K is close to but not  max cash you can spend on a analog bike. So roughly double over a 17 year period. Unfortunately salaries for most people have not doubled over that time period. Also while my bike today is undoubtedly better than that Moto lite, the joy of biking remains the same. I am certainly not enjoying it twice as much.


+7 Andy Eunson DBone57 bushtrucker Timer 4Runner1 lennskii Nologo

I have a bit of a hard time believing SRAM will support these with spare parts for more than 3-4 years, literally the fact that the new type T is not compatible with the old stuff proves that or also the fact they do not offer a rebuild seal kit for a charger 2.1 shows that company as no culture of good support down the road. 

I would also doubt that bike shops and even distributors will be willing to stock all those small repair parts if they are available, unless SRAM went through a major culture and organisational change it s going to be the same as usual for trying to get small parts from SRAM. Those products will be obsolete in no time... SRAM keeps disappointing me


+5 Andy Eunson Velocipedestrian Ryan Walters 93EXCivic Nologo

Hey Cam, next time you want to test the durability can you apply some lateral or rearward force to the cage?  I sometimes strike the side of my derailleur body but more commonly I hit the part of the derailleur closest to the ground.  If the cage cannot handle a strike or the force transfers and deforms any other part of the drivetrain or frame then having a derailleur body that can handle 1 million billion kilograms of force is mute.  

Where is the weakest point in the system?  How does this weak point put the whole system (drivetrain and frame) at risk?  To borrow a phrase, have we tied together two boats in a storm?

If there is no risk to the frame then my question is if Sram is willing to participate in the Right to Repair program?  The ability to replace some parts is a fine step towards a more repairable and renewable bike industry but I would like to see all parts replaceable and supported long term with parts availability.

Overall, interesting but I am not an early adopter.


+1 Skooks

That’s a good point. You hit something on the trail and put 300 pounds of force on the derailleur that’s 300 pounds of force. There is always a weak link but if that is designed to withstand what the worst directionless rider can do then it’s good. I’m sure some rider will break something though. I read this a bit like SRAM thinks gearboxes are dead in the water. People want gearboxes because they damage derailleurs and hangers regularly. You can’t shift many gearboxes under power. This new stuff you can. It’s also claimed to be stronger and we will see if that’s the case but I believe it will be. Gearboxes don’t come out of adjustment (as far as I know) and this new one won’t either. Or not easily anyway. Probably cheaper than many good gearboxes too. And a gearbox cannot be more efficient. Both have a chain drive and both will have a pulley system unless you have a hardtail. 

For me electric is a no go. More cost than I want with not enough benefit. I had a cross bike with DI2 for a couple years. While it worked well it wasn’t really any better than my mechanical shifting road bike.


+3 GB Velocipedestrian Nologo

My gearbox is from 2016. I'm not sure how many miles it has on it, but I've put about 4k on in the last couple of years, and only changed the oil once. Haven't even had to change the cables. I think the pinion retails for a lot less than this groupset, actually.


+1 ZigaK

Morgan - do you notice the lack of efficiency compared to a traditional drivetrain?


It seems very good in response to a rearward force to the cage, Gage. In that instance it can be pushed back and out of place but it requires very significant force. A simple push forward will reset it into its original orientation. I haven't had this experience yet but I have heard about and from early testers who have had this experience without incurring damage.

Frame damage seems unlikely to me considering how the mount triangulates around the frame and is braced by the axle, which is the source of much of system's strength.


+4 BadNudes Mammal TristanC 4Runner1

The tech and engineering looks nice... but being locked to a drivetrain system is not appealing.

Also kinda appreciated the "breakaway" advantage of the replaceable derailleur hanger. I get that the mech releases when it gets hit, but what about a stick in the spokes that it can't get out of the way of (yes I've had this happen)? What breaks first?


+4 roil Pete Roggeman BadNudes 4Runner1

Sipping my espresso on this quiet afternoon, feeling relaxed from a quick ride . An eyebrow raised at the sight of Srams latest derailleur.  700$ quite fascinating.  

Someone who is not introduced properly into the sport of mountain biking can be excused for asking . Does it come with a bike ? 

This tecky stuff is cool. I guess it's a step motor like you have on cnc milling machines . The motor remembers its last position.  Thus the derailleur knows through the step motor where exactly the gear is . I think . 

Derailleur in a can using a step motor mounted to frame in front of crank. To keep it compact a hi / low gear built into the rear hub . 

I'll build it myself.  

Then I don't know if I could still budget my kopi lewak coffee beans . 

Now I'm stressed.



Build it and they will come.


+3 Velocipedestrian cheapondirt BadNudes

Do the new reservoir bodies have enough room for clamps? I currently run my dropper and shift clamps inside my brakes, would this work? 

I just picked up a pair of dominions for this season (replacing previous code rsc model). I am surprised they didn’t update more on the codes. They are good brakes, but I don’t think they are at the top of the pack anymore with what hope, magura, trp and Hayes are doing.


+1 4Runner1

So odd to release the New Best Drivetrain Ever alongside brakes that are just Good Enough.

I have RSCs, that work just fine in my real world, but they do not make the cut for the imaginary dream builds...


+3 BadNudes Skooks lennskii

The funny thing is I get friends often asking me about bike tech Qs and as these drivetrains continue to get released that I have no interest in my ability to be helpful is getting pretty limited. We’ll unless the friend in question is open minded enough to ignore the latest firehose of marketing media and buy one of the perfectly great drivetrains that cost less than a state of the art cassette. 

To both big S’ credit they continue to pump out the older “obsolete” parts folks like me use. So I can’t complain about that.


+3 Briain BadNudes Skooks lennskii DancingWithMyself

i like how they are trying to sell their own version of Hyperglide plus, but boatload more expensive, electronic, and will undoubtedly will question the integrity of weight weenie frames in a crash.... While Deore 12 speed cassette/derailleur, an XTR chain, a derailleur hanger, and a XT shifter will do the same shifting seamlessly under load at a much less cost without the electronics at a lot less....

Also, if you crash on a T-Type drivetrain equipped on say, a Pivot, S-Works, Factor, or Scott mountain bike, in a minor crash (where a UDH derailleur hanger would have cracked/snapped/bent) that resulted in rear drive side dropout has cracking - while the t-type derailleur stayed intact - whom do I warranty the frame with, SRAM or the frame manufacturer?

+1 Andy Eunson

I'm not trying particularly hard here to stand up for SRAM because their product will either speak for itself over the next few years or it won't, but when was the last time you saw a snapped derailleur hanger, UDH or otherwise? For me, it's been years, and in that time, the people I've been riding with have evolved along with their bikes to be riding rowdier stuff with far fewer mechanicals and broken bikes and parts.

I think it's good to question anything new and wonder about the consequences, but most of the hand-wringing is just that.


+3 Niels van Kampenhout Skooks lennskii

As much as I appreciate new tech I wouldn't prioritize shifting when spending my money. The shifting on most drivetrains is so good these days that the added value of this is small compared to high end suspension or wheels. If i was still racing I probably would go for something high-end (read: Shimano XT or XTR) to get the shifting under max power benefits though. 

One thing though, there is so much focus on shifting under power but what about shifting when coasting? For winch and plummet riding I think that would be more beneficial. I find myself half-cranking quite a bit to get shifts done so that I am in the right gear when the terrain changes. A gearbox would obviously solve this issue, but comes with other issues.


+1 Cam McRae

Will be interesting to see how Shimano auto-shift (under their new Linkglide tech) will be received when they launch it end of 2023/24 as it aims to solve issues similar to those you've just described.


+2 fartymarty DBone57 slyfink nothingfuture

Bike industry loves to count grams but is cool with all this unsprung and rotational weight. New derailleur tech is just a bandaid on a gunshot wound. Can we move to gearboxes already?



Agreed.  If the big S's threw as much money at gearboxes (which I'm sure they have) the rear derailler would be long dead.


+11 fartymarty Mike Ferrentino NealWood Offrhodes42 JVP Konrad Hbar Andrew Major Jerry Willows Gabriel Barbosa DancingWithMyself

Eh, you'll have to convince me. The losses in a gearbox are fairly unavoidable, they're just less efficient. Cars and motorcycles have had a loooooooong time to perfect transmissions, and they're still pretty loss-y. Which doesn't matter as much when you've got a throttle and a pile of horsepower, but matters quite a bit when you're powering it with meat. And it overlooks one of the really nice parts of this new drivetrain - shifting under full load.


-3 Konrad Chad K DancingWithMyself

I'm sure with time they will become more efficient especially if ShimRAMo were on board - something like the Trinity mech-in-a-can shouldn't be too different from traditional drivetrain.  

I'd trade shifting under load for less maintenance / better crashablity.

On a XC / gravel bike I'll take a traditional drivetrain, on a bigger rig it's gotta be a gearbox.


+6 Konrad Andy Eunson Andrew Major Jerry Willows Gabriel Barbosa DancingWithMyself

Again, you'll have to try pretty hard to convince me that bicycle drivetrain manufacturers are going to figure out significant gains in gearbox efficiency that motorcycle, car, airplane, and industrial manufacturers haven't figured out in decades. 

But, there's also several gearbox options out there in the mtb world that are well tested - what's holding you back?



I'd also love to see an efficient universal gearbox in the market.  However dérailleurs work fine and have (slowly) evolved to something very good for their purpose. 

Why do we need a gearbox? To protect from the elements, and because the rear mech is vulnerable. The latter seems to have been fixed here (could be argued, but looks like a damn fine attempt to me).

So all we really need to do is form a protective layer or structure (a box?) around it and job done. The only negative is that it doesn't shift without peddling unlike some gearboxes. I don't know how advantageous that is though.


Money is holding me back.  I can change my whole 10Zee drivetrain for about £150 including mech and it works really well.

Give me a suitcase full of cash and I would buy a Starling Spur with shortened Ohlins DH38 and ride it everywhere.

+1 fartymarty

Your talk about efficiency is a bit of a strawman argument. I'm talking about suspension performance. 

There are more components/factors that impact efficiency than drivetrain alone. Rulezman (Italian suspension guru) is pretty keen on riding with less aggressive tires as they save you so much time on the climb and have little impact on descent.

FartyMarty is right about about Sram and Shimano not wanting to bring out gearboxes. They have invested a ton of money in maintaining the status quot. 

For the record, I'm cool with moving the cassette and derailleur into the front triangle like the Honda downhill bike style or Trinity.


+1 roil

I'm still convinced at some point in the future we will be riding gearboxes on mountain bikes.



On that very point. I think gearboxes will come back because of ebikes and honestly, a draggy gearbox is a constant compared to my almost permanently wonky derailleurs. That might more speak to my shoddy mechanic skills but I've struggled with keeping 12 speed running sweet


+2 Tremeer023 Blofeld

I can't believe Bosch hasn't released a motor / gearbox combo yet.  Shimano wont until someone else does it - although they have patents for gearboxes so I assume they have one in the works.  It makes so much sense to put a gearbox on an ebike - maybe this will trickle back to mountainbikes.



Gearboxes are bad at shifting under load, which is nearly a requirement for ebikes.

+2 Mbcracken BadNudes

Peak Torque on the YouTube doesn’t like it.

Good points I think. That mount is  relying upon frame manufacturers to build frames that meet exacting tolerances. Like they met tolerances for pressfit bbs.

He’s walked it back a bit with a second video.


+5 Pete Roggeman Niels van Kampenhout Mike Ferrentino Andy Eunson Cam McRae

I don't think that's a particularly good assessment...

As a number of people have pointed out in the comments, I think he has misunderstood how the derailleur is secured to the dropout (pinching the clevis around the dropout vs. clamping the inner plate and using the outer for radial support only). As a result, I think most of his commentary about alignment issues is moot. Axial positioning (axle frame of reference) should be no worse than a straight UDH, and far better than a bent one due to the pivot being concentric to the axle. Plus, as I understand it, they reference the cassette itself for axial position. Radial positioning will be subject to some tolerance stackup due to axle clearances and dropout tolerances, but this doesn't need to be super tightly controlled (is that stackup worse than typical variation in b-screw setting? Unlikely). Angular misalignment, again, yes subject to some tolerance stackups, but I tend to think they're pretty small. I think the issue with a typical bent hanger is more related to the offset between the axle and the derailleur mount, and the axial position that results from the bend angle rather than the angle itself.

I don't think his comments about the large bushing are particularly relevant, as the existing connection also has similar bushings.

Possibility for frame damage? Maybe, but I tend to think the way those loads are distributed with this mounting arrangement may actually be better. I think his talk about loads into frame pivots etc is nonsense.

I think he's absolutely right about the "magic wheel".

I'm somewhat optimistic that the derailleur design is an improvement, and by all accounts the shifting improvements sound great... I can't say I'm very happy to see no mechanical version released at the same time. As much as it may work well and there are some advantages, I'm just not really interested. Looking at the situation on the road side, and considering that some of the shifting "magic" may actually be in the shift programming, I'm a little worried mechanical could be gone for good at the top end of the range.

I'm also a bit dubious about some of the lack of backward compatibility... Changing to 8 bolt chainrings for power meter compatibility? GTFO!

+5 JD Niels van Kampenhout Andy Eunson el_jefe Cam McRae

There are plenty of YouTubers I follow and watch in a variety of industries or categories, but I don't tend to want to spend much time watching people speculate about something they aren't holding in their hand. I understand that he felt the need to put something out there on launch day, but despite the fact that he delivered the punchline himself to the joke that asks about how you'll know if you're in the presence of an engineer, he makes it hard to trust what he has to say because he doesn't have the product in hand.

YouTube is entertainment, mostly. Be very, very careful about whose opinion you trust. I'm not saying he's wrong or right, but without the product in hand or any experience with it, he's just another mouthpiece trying to get clicks.


+1 Skooks

I'm glad to see the bar raised, though accompanied by SRAM's extortionate pricing model. (There's a quote in another review that SRAM's designers were motivated by $17 helicopters from Amazon-- then they go and release a $200 shifter pod. Seriously, guys?)

It also represents the final nail in the coffin of interoperability. Nothing here works with anything from a third-party, save perhaps a crankset in a pinch. While I hope they bother with mechanical versions of that derailleur, I'm not holding my breath. NX and below may well end up carryovers.


+2 Cooper Quinn JVP

A crank is the only thing compatible between brands as is, so that isn't really any different. To use a Shimano drivetrain you can just put a UDH on the frame and mount up whatever other drivetrain you like.



SRAM's previous 12S drivetrains would work with other other chains and cassettes. This one won't. It's even less compatible with third-party components than Hyperglide+.

+7 Deniz Merdano dolface dhr999 DancingWithMyself Timer el_jefe lennskii

Complaining about cross-compatibility on launch day is disingenuous. There will be 3rd party parts that fit. Give it some time.



Well, the question is will the third parties have to license to make chainrings and the like or will SRAM just let anyone do it?


+1 Cam McRae

This new groupset sounds all great and fine in theory, but I guess SRAM overshot their goals a little bit with this. How will any product manager ever put this on a bike that is to be sold to the masses?

Maybe the tech will trickle down to GX or even NX (which is standard equipment on many sub 3k bikes), but all that drivetrain mixing with Sunrace cassettes, SX chains and Aeffect cranks must be carried on somehow, and they will become inventive... we will see. Maybe it's the same way the old first Saint mech went. Into the bin, new from the bike.


+1 Deniz Merdano

This looks amazing for the high end. I’m making the assumption that GX with cables is coming within a year. 

Shimano absolutely laid out the competition in the mid range with Linkglide, and SRAM is absolutely laying out the competition at the high end with this. 

Interesting times!


+1 Andy Eunson

anyone remember these? I liked mine. didn't even need a new hanger standard. but that was back in the day of gs and ss cages, so slightly less exposed to roots and rocks.


I don't recall every seeing that. Very cool.



Shimano also had a direct mount, although it was a bit more of a band-aid as there's still a big bendy piece in the middle than the now-current SRAM concept.



Weren’t these derailleurs low normal? I can’t remember if they were available in high normal as well. Low normal was not well received and perhaps that’s part of why this pictured system died off?


+1 Cam McRae

About to slap the XO Transmission on my new Insurgent LS build. Very curious about crank compatibility, ie using existing XO carbon cranks instead of the new heavy aluminum ones. Seems like, from Cam's musings, one could just add on a 104 BCD adapter from, say, North Shore Billet, and get a new T-type ring and you're set? Weight difference between XO Transmission cranks only (550gm) and current XO Eagle carbon cranks (420gm) is 130gm (actual - just weighed it). Might have to hold onto my existing carbon cranks. ya ya, I don't care that some people 'don't care about weight'....

Also curious if it will still work 100% fine with oval rings (whenever they may be released) as I prefer ovals now. will have to just deal with the round ones for now haha!



No, not yet new cranks use 8 bolt direct mount and the teeth interface is meant to be different. But I'm sure the after market will you covered soon. There's a youtuber called peak torque who was reaming this design but he reckons it will only work with even teeth on a cassette so to me that would mean ovals are out


+1 Cam McRae

I was refering to Cam's comment re hack - "There is a hack to the new cranks requirement, however, and it involves eMTB cranks and the available 104 BCD chainring T-Type chainring. Finding a current 104 BCD crank may not be easy, but it's not impossible either. And you might even have one in a parts drawer."

So simply get a 104 BCD adapter, like the North Shore Billet one, and obtain (once SRAM sells singly) the 104 BCD T-type chainring.


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