Words by: Liam Woods
Way back in 2016, SRAM introduced its Eagle drivetrain. Later this became the massive SRAM Eagle Ecosystem family that has five different levels of SRAM Eagle to choose from. Now in 2020, SRAM is releasing its new Eagle V2 with the Eagle Expansion ecosystem for the model year 2021. It has a new cassette range that has a massive 520% gear range, as well as new colors on both the cassette and chain. SRAM also says that all of their chains and cassettes are now approved for e-bike use, and each model of Eagle has a single click shifter for those e-bikes as well. Yes, I mentioned new colors; there is now a Copper colorway for the X01 and XX1 cassettes and chains. Last, but certainly necessary to set up your new Eagle 10-52t cassette and rear derailleur, is a new chain gap tool to dial in your b-tension screw to the perfect adjustment for each bike.
Why do you need more range or an updated SRAM Eagle? There are more updates than just getting an extra 2t on your cassette. The rear derailleur design and performance have been improved, along with an update to the colorways as well. And of course, there is the 52t rear cassette that now offers a massive 520% gear range. If you have ever just needed that little bit of extra gear to make a climb, or you are on a long ride and just want to save the legs, SRAM found that just an extra 2t on your rear cassette can make all the difference. If you are a strong rider, size up your front chainring and increase your all out speed. Or you can still use the 10-50t cassette with the new Eagle V2 parts, and those 500% range cassettes will still be made for a long time.
Another huge update is GX Eagle was made to be more precise and durable, perfect for the everyday rider. Made to compete with the other mid-upper range drivetrains like Shimano XT, SRAM GX Eagle now gets the option of an alloy or carbon crankset, and uses a newly designed 10-52t GX Eagle cassette to give riders the crisp Eagle shifting you expect at a slightly lower price range. GX Eagle is the workhorse of the SRAM Eagle ecosystem.
SRAM XX1 Eagle is still the top end shifting you'd expect for the cross country rider, or the rider with weight in mind. For this new expanded range of XX1 Eagle, the big changes are going to be in the rear derailleur where a new cage architecture and design provides even smoother shifting and all out performance that is also made to work seamlessly with the new SRAM 10-52t XG-1299 cassette. The other big change in the Eagle lineup is that the new cassette gets a massive 520% range with the introduction of the 52t cog. The rest of the cassette range remains unchanged, and you still get the close precise shifts you expect with SRAM Eagle, but now your granny, or bailout, or as I like to say, Eagle gear just gets a jump up to the 52t to help you spin it out.
Similar to the first gen of XX1 Eagle, the new XX1 Eagle gets all the carbon bits you expect, like a carbon cage on your rear derailleur, a carbon shift paddle and cable cover, and the lightest carbon cranks SRAM makes to really get that high end feel. The looks of XX1 has also changed, and is now streamlined to have a more subtle approach on the shifter, derailleur, and cranks in order to make the new cassettes really pop. For XX1 and X01 you have the option to choose from Black, Rainbow, Gold, and now Copper colors for both the cassette and chain.
SRAM X01 Eagle is the best drivetrain option for the aggressive trail or enduro rider. Contrary to many riders’ beliefs, X01 Eagle is at equal level with SRAM XX1 in terms of quality, but the performance focus is shifted from lightweight to durable. You lose some carbon bits, but you get some alloy parts to take that extra smack or extra shuttle run that might take out some lightweight parts. Many of the same updates that you saw in XX1 are also put into X01. The rear derailleur gets a new design in both architecture and graphics. The colorway for X01 was made to match all the cassettes and chains for a clean look no matter what drivetrain level or bike you are looking to put it on. Sharing the same cassettes, X01 also sees the 520% range of the updated Eagle Expanded range.
The big story is the new GX Eagle from SRAM, the drivetrain for the everyday rider that wants a drivetrain that works consistently without any gimmicks. GX Eagle is the workhorse for the SRAM Eagle family, and it also sees many of the updates that XX1 and X01 received as well. The redesigned rear derailleur and the 10-52t cassette with 520% gear range is also found in GX Eagle. GX Eagle gets its own cassette that has pinned cogs instead of the fancy machined cogs like the XG-1299 cassette. The XG-1275 cassette still runs on the SRAM XD driver body, so upgrades from the previous Eagle generation are easy. The colorway is also updated for GX, so if you want to run GX Eagle parts with the higher end and lighter XG-1299 cassette, you are able to choose any color and still have it look like it’s supposed to be there. For the all-day rider, SRAM GX Eagle works day in day out.
The performance of the new extended range 10-52t Eagle cassette with either of the SRAM AXS rear derailleurs that are forward compatible as well as the new updated Eagle rear derailleurs is smooth like you would expect from SRAM. Precise, smooth, crisp and quiet are all words I use to describe SRAM shifting, and even with the new jump up to the new 52t cog, it remains as smooth as can be. With the new mechanical Eagle, set up is as normal, but like SRAM Eagle, the B-tension needs to be adjusted properly with the SRAM’s B-tension Chain Gap Tool.
If you are installing the new wider range cassette on an AXS rear derailleur, you need to get the new SRAM B-tension Chain Gap Tool. The upper pulley needs to sit in a different position than with the 50t cassette, and it's actually quite a bit different. When I was installing the new cassette on the current SRAM AXS rear derailleur I was surprised to see how much B-tension was needed to make the shifting smooth.
When riding the new SRAM cassettes I didn't notice any performance decrease with the new 52t cog versus the 50t cog. The jump is larger and you do notice it when shifting but it's not hindering. You can still shift up and down while climbing, no problems. Just as you would expect, SRAM’s performance is top-notch and this is no different.
Short Answer: EHHHHHHH... YES
Long Answer, do you really want the long answer? If you run a new 10-52t cassette with an old mechanical Eagle rear derailleur, SRAM says that will not only void any warranties but also the performance will not be up to the level that SRAM intends for their parts. So you want the real answer? Yes, it does work. You can technically run the new SRAM 10-52t cassette with your current generation of SRAM Eagle. Does it shift as smoothly as the new Eagle V2 that is designed for the 52t? No. This is where you feel that gap up to the 52t cog, especially when in the 52t and shifting into the harder gear. It feels like a semi-bad shift, for lack of a better term. It's not horrible, but it doesn't feel like the usual buttery smooth SRAM Eagle we all know and love. Plus, let's not forget all the parts about voiding any warranty as well. If you are desperate for more range without dropping your front chainring, then maybe you take the slight performance drop in shifting and run the 10-52t to get that little bit extra gear.
Who is this new SRAM Eagle expanded range for? Well, really any rider out there. XX1 will grab the attention of the cross country rider or the trail rider looking to shave some grams while X01 is for the rider who looks for the steepest, chunkiest way down the mountain and isn’t afraid to take a couple smacks. GX Eagle is the workhorse of the family, ready to ride all day, every day, with top notch performance in a more affordable package. GX Eagle will not complain and would love to join you on all your riding adventures. Don't think you need more range than your current 10-50t cassette? Well then add some teeth to your front chainring and get a bit more speed. Or for most of us, the 52t expansion will be a welcomed bailout gear to help you spin up the steepest sections of trail.
The new SRAM Eagle expanded range works great for any mountain bike rider looking for top performance without any issues. More range, better looks, and a new color, we can't wait to see what crazy new builds pop up soon.
After four years of amazing performance, SRAM brought in some fresh looks and design to update the Eagle ecosystem. With a larger rear cassette that has 520% range, riders can now choose to spin up the climb or bolt on a larger chainring and get that all-out speed. With all three top levels of Eagle getting updates, XX1, X01, and GX, there are now options for the weight-conscious rider, the burly enduro rider and the all-day rider who just wants to get out and rip. Streamlined colorways in all versions allow the mixing and matching of the SRAM Eagle cassettes and chains to not only look good with the drivetrain of choice but also on any bike you choose to put it on. SRAM Eagle was already our favorite drivetrain, and now it just performs and looks that much better!
This article was written / authored by Liam Woods. Liam has been in the bicycle industry for over 10 years as a racer, professional mechanic, service manager and as of late, media and content creator. Liam has ridden thousands of different bikes, ridden countless components, tested endless MTB apparel of all kinds and written reviews on it all. He's a key piece to the Worldwide Cyclery "All Things MTB" content creation puzzle. He also makes consistent appearances on the Worldwide Cyclery YouTube channel and Instagram.