SRAM Eagle Rear Derailleur Chaingap Adjustment Guide [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. 

Keeping your drivetrain tuned up is essential to maintaining a happy bike, and a happy bike means a happy rider. Thankfully, SRAM makes the Rear Derailleur Chain Gap Adjustment Gauge which makes adjusting your derailleur a breeze. Wyatt recently got his and his drivetrain has never been more dialed. Read on for more!

Wyatt's Review

A bike I recently purchased came installed with a SRAM NX Eagle drivetrain. The bike came with the drivetrain decently adjusted but after moving the shifter around and messing with the cable routing due to installing a chain guide, I needed to make adjustments since the shifting felt worse than how it was originally. This was the first time I have owned a bike with a 12-speed drivetrain so I was not aware of how sensitive they can be when making adjustments. After about a week of messing with the high and low limit screws and barrel adjuster, I still could not get the bike to shift the way I wanted it to. After some research, I found out that SRAM Eagle rear derailleurs are really sensitive to the adjustment of the B-screw, which I had not adjusted or checked. I went on SRAM’s website to check what gap they require between the cassette and rear derailleur jockey wheel (chain gap) and did my best to adjust and measure the gap with a set of calipers. Unfortunately I still wasn’t able to get it right so I caved and purchased the SRAM Eagle Rear Derailleur Chain Gap Adjustment Gauge as a last attempt on my part to get my shifting to where I wanted it, otherwise it was off to the bike shop for assistance.

Using the gauge is a very straight forward and quick process. There is an extruded, curved feature that allows the gauge to rest against the teeth of the rear derailleur jockey wheel. In other words, it constrains the gauge from moving around while checking the chain gap distance. There are also visual aids on the gauge that show where the jockey wheel and cassette teeth should line up. The visual aids are nicely done and easy to read due to the differences in depth and texture used. The chain gap has been adjusted correctly when the teeth on the jockey wheel and cassette line up with the visual aids on the gauge.

It will take a couple checks and turns of the B-screw to get everything lined up, but the gauge takes any guesswork out of making sure that the chain gap is at the correct distance which is a big time and mental sanity saver.

Final Thoughts

The SRAM Eagle Rear Derailleur Chain Gap Adjustment Gauge is a really nice tool to have for those who are installing a SRAM Eagle rear derailleur on their bike or are having issues with shifting performance. While it’s possible to adjust and measure the chain gap with other methods, this tool is worth it in that it saves the user time and is very easy to use. While I was initially skeptical and resistant to buying the gauge, I am very happy with my purchase and highly recommend this tool to anyone.