SRAM T-Type XX Drivetrain - Is it Worth the Upgrade? [Employee Long Term Review]

Words by: Trevor Mejia

Intro 

In March 2023, SRAM unveiled their revolutionary and innovative new drivetrain, Eagle Transmission, or T-Type for short. It involves a radically new design, taking away the derailleur hanger and replacing it with a direct mount bolt on derailleur. They claim this system is able to be shifted under significant load without missing a beat, while keeping the drivetrain quiet, long lasting and problem free without any adjustments, something that no other drivetrain has been able to claim until now. Seems good right? 

SRAM developed UDH (Universal Derailleur Hanger) a few years ago which most manufacturers have adopted as a standard in the industry. T-Type requires a UDH interface, ditching the actual hanger and allowing the system to work correctly. There was a lot of controversy when this was first released, the whole point of a derailleur hanger is so that it would take the hit and bend if smashed against a rock, ideally saving your derailleur and frame from catastrophic damage. It was argued that now if the bike took a good hit that your frame and derailleur would be compromised but it is not the case. We even filmed a viral video, putting my whole body weight onto the derailleur body and nothing was damaged or bent. This works because now the derailleur is now threaded onto the axle, keeping the body incredibly strong and stiff. The T-Type derailleur still has their genius knock away feature found on the AXS system, where if it takes a hit, the derailleur moves inboard a few mm on its own to help ease the brunt of the blow. SRAM made this XX version intended for trail use. Not as robust as the XO group or as light as the XX-SL group, it fits perfectly in the middle of the two!

T-Type is a wireless only drivetrain that works together in a proprietary configuration. It features a unique 10-52t cassette and flat top style chain. It comes standard with a 2 button pod controller, but this can be changed to any AXS compatible shifter. I have been riding this drivetrain now for a little under a year, putting a significant amount of miles full of use and abuse. Let’s get into how it has performed. 

Setup

I installed the XX version drivetrain on my custom built Yeti SB140. It ties in nicely to the whole SRAM/Rockshox build I was going for. Their ecosystem compliments itself very well for a clean and tidy look. I took off the UDH and mounted the derailleur. The rest of the components are a standard install. There are no adjustment screws on a T-Type derailleur, the system knows its limits and the variables are eliminated in the initial and very important setup. SRAM has a database of UDH compatible bikes on their AXS phone app. This is crucial to find out the proper chain length, setup key and cog to set the B gap. This is based on your bike model and size, it knows how long the chainstay is and what configuration that you need for the system to work correctly. Without the proper setup, Transmission will NOT work correctly, it is the most important part of how your drivetrain will perform. It is worth double checking and watching their video on how to do it properly. Once performed, shifting is relatively good, but can only be tested while the bike is ridden and shifted under sag. I made a few micro adjustments using the POD controller and have not touched it since. The POD controller came with a separate handlebar mount, but I switched this to their MMX (matchmaker) integrated clamp for a clean look but more importantly I was able to fine tune where it sits on my cockpit configuration. I reversed the default shifting orientation in the AXS app and off to ride! 

On the Trail 

Shifting on a transmission system is unlike anything I have felt before. It is smooth, quiet and you really can shift under load while sprinting with no issue, just like what SRAM has claimed. Gone are the days of missing a shift, twisting a barrel adjuster or messing with a b-tension adjustment screw. It is noticeable that shifting speed is much slower than the old AXS system. You cannot dump the gears up or down the cassette anymore. This is because the shifts are intentional and are programmed to work with the shift ramps to have accurate jumps. This, along with the addition of a flat top chain makes for a stronger and longer lasting drivetrain. They are expensive, yes, but I have yet to see one of these chains break or wear out since they have been introduced almost a year later. This includes e-bikes which are notorious for being hard on drivetrains. The cassette features unique shift ramps to work seamlessly with the flat top chain and the XX version looks pretty sweet I may add. 

The derailleur has proven to be as robust as claimed. I have hit it a few times on rocks while riding downhill and you can hear the overload clutch move the derailleur inboard to get out of the way momentarily. Shifting resumes as normal after this and has continued to perform. Although you cannot damage the main body of the derailleur anymore, thanks to its direct mount design, it IS still possible to damage or bend the pulley cage. This is where you will run into shifting issues. Thankfully, SRAM has made it possible to replace the cage assembly including clutch, inner cage plate, and parallelogram arms. Nice! 

The clutch on the derailleur has been drastically improved, keeping chain slap to a minimum. It will still slap on hard bottom outs or big hits, but over small chatter and even normal trail riding, you do not hear the chain moving around at all. It’s a pretty cool feeling to hear only tires gripping the ground while you are riding! This also improves chain retention, and on this bike without running a chain guide I have yet to drop a chain, even while pedaling through some questionable terrain. 

The new pod shifter was a bit strange to get used to. I was convinced that the AXS rocker paddle upgrade was the best performing shifter for the wireless system as it mimicked the conventional cable trigger shifter. I wanted to give this new pod controller a fair chance. After spending a lot of time with it, I don't even think about shifting anymore, or whether I am clicking the up or down button on the pod. With the matchmaker integration, I can fine tune where the shifter will be so that it takes minimal effort to make a shift. The XX system comes with the POD ultimate controller which features rubber buttons as opposed to plastic ones the normal version. It also comes with the option of concave or convex buttons and I chose to keep the convex ones as it felt natural. 

The XX version of the T-Type Drivetrain comes stock with 2 integrated yet removable impact/bash guards. I spent a fair amount of time riding this winter in the Arizona desert, climbing up, on top of and over sharp rocks and found this bash guard to be very useful. I ended up taking the top guard off, relative to riding with my left foot forward. The guard took quite a beating and saved my chain and chainring from impact damage. The crankset came stock with 170mm cranks and a 32t chainring. I found this combination to be perfect all around combined with the 52t cog on the rear cassette. Because of the improved clutch on the rear derailleur and flattop chain, the chain never came off the chainring and it was as quiet as can be. The chain has not stretched or anything strange happening. The XX cranks are made from carbon with a foam filled core for additional strength. It comes with crank boots thankfully and has taken some beatings from the loose Southern California rocks that fly up and hit the bike but they have fared well all things considered. 

Who is this for?

T-Type is for serious riders who are willing to spend a little extra cash for the best all around performing system. If you are looking to make your bike as quiet and smooth as possible, Transmission is the way to go. It has made my personal rig the quietest best performing that I have tested so far and I am still impressed when I go to shift. Racers and those who like to push their bike hard will benefit from this drivetrain because it inspires confidence. It is a unique bit of kit and you need to understand the level and quality of the product that this drivetrain offers. The XX version in particular is great at being a lightweight system, while having strength in all of the right areas. A bike in the travel range of 130-160 is ideal for this as it can be ridden on pretty much any trail but not necessarily excelling on the extreme ends of the spectrum. 

SRAM has future proofed their product with the creation of UDH, having companies to adhere to this new standard or fall behind, and T-Type only works with UDH frames. We are even starting to see frames being developed without ports for shifting cables, forcing their customers to run a wireless drivetrain. Even though I ran this drivetrain on a trail bike, I believe this system as a whole excels on an e-bike! Specifically the X0 T-Type  that is a bit more robust. E-bikes are notorious for being extra hard on drivetrains, and being able to shift under load (motor power) means a better experience for this group in particular. 

Pros:

• Can take a beating on trail 
• Shifting under power is incredible 
• Improved clutch for a quiet ride 
• Strong and longer lasting chain 

Cons:

• Still have to remember to charge a battery 
• Slower shift times compared to AXS 
• Does not work on every bike, only modern bikes 
• Components are expensive 

Final Thoughts: 

This drivetrain has been nothing short of impressive so far. Yes, a normal cable 12 speed system works great and that has a time and place. An Eagle AXS system is amazing as well but Transmission has raised the game and pushed the limits of what is possible. SRAM has gone a long way to develop this drivetrain, thinking outside the box and having it integrate into their whole ecosystem of bicycle products. It has become our new favorite drivetrain and has set the standard for the on bike experience.