SRAM GX Eagle Rear Derailleur 520% Range [Rider Review]

Our "Rider Review" article series features the honest reviews from verified purchasers of Worldwide Cyclery. They contain the photos, thoughts, feedback & overall review you are looking for.

Quality drivetrain components at a reasonable price seem like an oxymoron these days, unless you've experienced SRAM's GX Eagle. Its combination of performance and value is hard to beat. Our friend Scott recently upgraded his steed and loves the crisp, smooth shifting. Read on for more!

Overview

Riding your bike should be fun and stress-free when it comes to the equipment of the drivetrain. Shifting should be efficient and precise when negotiating the different trail sections so you can focus on the joy of just riding on your favorite trail system.

I purchased my bike equipped with the SRAM NX build due to the competitive price point as the suspension, wheelset, and dropper seat post was what I was looking for. The NX rear derailleur was somewhat difficult to get dialed in and I found myself more focused on working the system to get the bike in the correct gear. Countless times adjusting it on the fly, at the house, and even my local bike shop.

I decided to do some research and after finding that SRAM Eagle components are interchangeable, thanks to the videos produced by WC it was an easy pick to upgrade to SRAM GX. With the heavier spring, small changes to the construction of the cage, and the fact it would work with the rest of the group set, I figured I couldn’t go wrong.

SRAM packages their equipment like no other. Set in its own box with a stamped cardboard lid with a smooth finish, it has a rich and solid feel to it. Getting to the contents of the box, you will find a super detailed instruction manual, the derailleur, and alignment tool. Since this is the lunar 520 model m, I did notice that the tool is different from that of the older red-colored alignment tool.

Installation was extremely straight forward. The GX derailleur went on in the same manner as the NX derailleur. The GX stood out in craftsmanship right away. There was a noticeable difference in the stiffness overall. The running went just as smoothly. I did opt for the newer 520 so I can upgrade to the new GX cassette in the future. On the bike stand, shifting was crisp.

Once installed and out on the trail I wanted to see just how much of a difference there was. I decided to head out to a local trail in North Carolina in the Uwharrie National Forest. This would offer about 2500 feet of elevation change, a quick downhill section, and then right into some demanding climbing. The GX derailleur did not disappoint from the get-go. I instantly noticed a positive feel of the shifting where the chain settled quickly into the desired cog needed to negotiate the trail. No longer was there the need to upshift twice then down one to get into the right gear. With a quick push or pull of the SRAM shifter, you were in the correct gear and not searching for what seemed right.

I instantly noticed a positive feel of the shifting where the chain settled quickly into the desired cog needed to negotiate the trail.

I feel that the cage doesn’t flex under load due to the increased stiffness. The tighter tolerances prevent the chain from being thrown off the cassette either into the spokes or between the small cog and the frame.

Final Thoughts

I have done 4 rides in the SRAM GX derailleur at about 20 miles per outing with zero issues. The bike is a pleasure to ride and will be adding this set up to my son's bike here in the near future as he has NX also. Well worth the upgrade for a simple price of mind and to add to the enjoyment of riding your bike.