SRAM X01 Eagle

SRAM's 1x12 Eagle drivetrain is setting a new standard for how a bike can pedal.

SRAM X01 Eagle Drivetrain Review

The evolution of the modern mountain bike has come a long way in the last five years, and SRAM’s latest development of the 1x12 X01 Eagle drivetrain is yet again changing the face of current technology—out of good reason and necessity.

Over the course of the past few years, mountain bikes have truly tapped into the core fundamentals of what developed the sport in the first place; freedom and adventure. Today a bike must be capable of everything from aggressive all day epics, to short lift assisted shuttle laps and anything in between. Although the new breed of all-mountain bikes is a world different from where the mountain bike first began, it has brought on a new life of exhilaration and excitement, made possible by innovations like the 1x12 SRAM Eagle lines.

The Eagle's chainring combines narrow-wide teeth with a positive-rake tooth shape to help keep you from dropping the chain.
Twelve cogs compacted into the same space as 11 means it's a much tighter fit.
SRAM re-engineered the chain for the Eagle, with hollow pins and their new PowerLock connector.

Riding Eagle:

The concept is as simple as the execution, keep the front chainrings at the all-time minimum (simply one) while creating an effective pedaling range and making the number of gears more efficient. SRAM did this by building off of their famed 1x11 drivetrain and adding an additional twelfth cog into the mix, creating the ultimate pedal power in a cassette that ranges from 10 to 50 teeth. While in the 50 tooth cog I could pedal the bike up what the earliest 90’s bikes could only climb in the infamous “granny gear.” On the flats and descent, I could still get enough out of the pedals in my 10 tooth cog to add extra speed or match the flow while not having to think about changing or potentially dropping the chain from my front ring. The Eagle’s front chainring now couples the narrow-wide design from generations past with a longer, positive-rake tooth shape to reinforce chain retention and keep from throwing the chain from your ring in even the deepest trail compressions.

Considering the shifter actuations, the rear cassette has a smooth and precise feel, but must be set-up properly due to the limited amount of space between the cogs from adding that twelfth gear. To be completely honest, I have been riding the X01 Eagle for 90-plus days with minimal maintenance to truly put it to the test, and with only a new cable & housing swap in those 90 days, the 1x12 set-up has run flawlessly. SRAM claims that the new, tighter spacing in the rear cassettes and narrow-wide features on the front chainring and derailleur pulley wheels help increase the lifespan of the chain, cassette and ring—which seems to be true based on the minimal maintenance I’ve done. That initial setup, however, is crucial to the longevity and smooth operation of the X01 Eagle and the most important factor according to the team at SRAM. Three months of testing later and I’ve realized this couldn’t be more true.


As mentioned, the installation of the new Eagle drivetrain systems is imperative to the performance and overall experience. With that being said, it is quite simple and just takes knowing the new setup measurements that differ from drivetrains of the past. Ironically, SRAM has thought this through and offers a measuring device called the ‘Eagle Chain Gap Tool’ with each drivetrain to ensure the spacing is correct. The main spacing difference with the new Eagle system is due to the fact that the cogs are spaced closer together to fit in that extra gear on the cassette. Because they are so close together and have a bigger range, the top derailleur pulley wheel must run closer to each actual cog then on their existing 1x11 drivetrains in order to keep the shifting tight and accurate. This is done simply by adjusting the b-tension screw to reach the new parameters of the 1x12 system, then its normal adjustment with the limit screws and proper cable tension for seamless shifting. Thankfully, SRAM has produced a detailed installation video that can answer any questions. Although most times a local shop will set you up on your new drivetrain, it is imperative for the DIY customers to know about the new installation for best results on 1x12 Eagle systems.

The Eagle derailleur's pulley technology provides fast and smooth shifting and a noticeably smooth pedal.
The top pulley is much closer to the cog on the Eagle drivetrain, meaning precision is everything when getting it dialed in.
The Eagle Trigger Shifter has a snappy feel and a customizable setup.
The Eagle is 12 gears of supreme mashing power, whether charging uphill or sending it down.


Eagle offers an array of set-ups for each rider at different price ranges. Due to the extra gear in the back, I went up two teeth from a 32t front ring to a 34t ring, which made me faster on the more pedally terrain while still allowing me to climb the steeps with a similar range to what I was used to on my 1x11 setup. SRAM also offers the system with a Trigger Shifter or Grip Shift option and has a few different options to make the system custom to each rider. The XX1 system comes with slick gold accents and a completely gold chain that pay homage to one-and-only Mr. T, or you can roll more stealth with their red and black X01 system that I tested. I particularly liked the black chain and cassette as it appeals to the Northwest’s drab clothing color schemes and style, but to each their own and SRAM offers it.


All and all, I have been loving the new SRAM X01 Eagle drivetrain. It has performed with minimal maintenance—not recommended—and helped pursue my passion to ride diverse terrain with one bike. With any new technology in the bike world, there is a cost to getting on the newest and greatest advancements—the Eagle is fresh to the market and currently the only 1x12 drivetrain available—and the price tag reflects the exclusivity. Per usual, prices do tend to drop after time (although there is no concrete evidence of that happening anytime soon). However, even as is, I think the price tag associated with the new 1x12 systems is well worth the money and will only increase any on-trail experience and offer a whole new range to you daily ride.

SRAM Eagle Drivetrain
MSRP: $1,193

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Sram XO1 Eagle