Did your new bike come spec’d with SRAM Eagle 12-speed drivetrain? Specifically X01 or XX1? If so, you should keep reading. SRAM Eagle 12-speed came to the market a few years ago and has really been the benchmark ever since. Many bikes in the $3000 and up range are coming stock with Eagle 12-speed. While that is great and I bet everyone is loving it, I’m sure a lot of you have got to the point where things like chains and cassettes are starting to wear out. Hopefully, you replaced your chain at the correct wear interval and you got the most use out of that expensive X01 or XX1 cassette. Eventually, the cassette will wear out as well and there are only a few options to replace your 12-speed cassette on the XD freehub body. You have three options from Sram and one from e*thirteen components. Two with a splined freehub body, you have two options, Sram NX Eagle, and SunRace MZ90 12-speed, both have 11-50t range, less than both X01 Eagle cassettes and much less than E13 cassettes.
While you could stick with the amazing SRAM options, another great option is the e*thirteen TRS+ 12-speed cassette with a 9-46t gear range. There are a ton of benefits with the e*thirteen cassette. As listed above, the e*thirteen cassette is cheaper than X01 by over $100 and happens to be 20g lighter. I could end my review right here, but I'll keep going. So we have a cheaper and lighter option over the X01 or XX1 cassettes, but the e*thirteen cassette would also be an amazing upgrade to your current GX Eagle cassette since it’s only $35 more in price while coming in 114g lighter. Another alternative replacement would be the SunRace MZ90 12-speed 11-50t cassette, while it doesn't use an xD driver like the E13, it could be an affordable option to Sram Eagle cassettes. As I mentioned above the E13 TRS+ 12-speed cassette is a great upgrade to your current GX Eagle cassette, but also as a replacement once it wears out. For only a few more $, you can get an insane upgrade over GX Eagle.
In addition to being lighter and cheaper than X01, the range is also different with a 9-46t gear range. You end up with 511% range over the 500% range offered by the Eagle cassettes. Not only do you have more range but also a smaller jump between gears (9-10-12-14-16-18-21-24-28-33-39-46t). This means smoother shifting across the range of the cassette. The 9 teeth high gear can be used to tweak your front chainring size. You might want more high gear while keeping your front chainring the same, however, I ended up sizing down my front chainring. I found that I have both enough low and high range with this combination. If you care about weight, you already drop 20g with the e*thirteen cassette over the SRAM Eagle X01 cassette, and now it’s easier to drop the chainring size. It may be small weight savings but it’s weight savings nonetheless. A smaller chainring can also improve clearance when going over rocks or logs, offering fewer times that you might bash that chainring.
Another really cool feature of the e*thirteen TRS+ cassette is it comes in two halves, giving you the option to replace either cluster in the future. If you always wear out your low gears but the high gears are in great shape, you can purchase just the low cluster and save more money down the road!
Riding the e*thirteen cassette has been super nice. I first got it on before heading up to race the Downieville Classic. Not only is weight a concern with this race, but so is having the correct gear range for a grueling hour-plus climb and some very high-speed sections topping over 30mph. The e*thirteen cassette performed flawlessly and I didn’t once have a shifting issue or lack sufficient range. As I mentioned, I switched to a 32t chainring with the e*thirteen cassette and the 32t front/46t rear cog combo was plenty to keep my legs spinning.
Shifting performance is just as good as the X01 cassette. I will say you can feel a difference between the two but that’s mostly in the way the chain and cassette work together. The e*thirteen feels a bit more crisp and sharp, even if under load. Each click of the shifter comes with a confident and crisp grab. I would almost say it’s a “klunk” but fear that may be misinterpreted badly as in my mind it's a noise indicating precision.
After putting in some serious miles on this e*thirteen 12-speed cassette, I would be hard pressed to return to the original X01 cassette. There isn’t anything wrong with the X01 but with the e*thirteen being a bit lighter, cheaper, and offering the same performance… Let’s just say it’s staying on my bike for the time being.
If you are looking to upgrade or replace your Sram Eagle cassettes, I would strongly suggest looking at the e*thirteen TRS+ 12-speed cassette. There are so many benefits, from weight savings to money savings, all without losing any performance. It’s hard to say no to a win-win option. A tighter and larger gear range, and the ability to run smaller chainrings for additional weight savings and ground clearance, the e*thirteen TRS+ 12-speed cassette checks all my boxes.
SRAM 10-50t options: