SRAM has swooped in and grabbed a 10/10 MBR rating.

Product Overview

Overall rating:

Score 10

SRAM Eagle XO1 groupset



  • Wider gear range, quieter and smoother shifting, greater durability, same price as the current XX1 and XO1 groupsets and only marginally heavier.


  • Only the chainring is backwards compatible, you may not need gears this low.


SRAM Eagle XO1 groupset review


Price as reviewed:


SRAM Eagle is the new 1X drivetrain with distinctive 12-speed 10-50t cassette and chain hugging, X-Sync 2 chainring. How does it ride?


  • SRAM XO1 cranks, £328
  • Rear derailleur, £185
  • Shifter, £112
  • Cassette, £302
  • Chain, £50
  • Groupset, £977

Watch: We ride the SRAM XX1 Eagle 12 speed groupset

SRAM Eagle

It’s currently available in a XC race livery called XX1 or a more trail-focused option called X01. Both use the same technology but have slightly different finishing and prices. Eagle X01 is the one for trail riding so that’s what I’ve been running on my Nukeproof Mega 290 for the last 12 months.

>>> Shimano XT (2016) groupset review

When I tested SRAM’s 11-speed X01 groupset I has a few issues with chain loss and accelerated chainring wear but I’ve had none of those with Eagle X01. I think the main reason this 12-speed groupset has been more reliable is because SRAM spent a long time developing the thread that binds it together, the 12-speed chain.

sram eagle

Ergonomically situated shifters aid an easy change

SRAM Eagle chain

The links that make up the Eagle chain have a smoother radius, with no sharp edges or chamfers and the pins are also extremely flat and flush to the outer plates. The new shape is quieter, smoother and, combined with a new Hard Chrome heat treatment process and a titanium nitride coating, reduces wear on both the ring and cassette sprockets. SRAM claims an Eagle chain will last 3-4 times as long, and since I’m still on the original, I can totally bear that out.

sram eagle

SRAM Eagle cassette

Another keystone in Eagle performance is the X-Glide 2 cassette. It’s machined from a single piece of chromoly with the biggest 50t cog made from aluminium. This keeps the weight as low as possible but due to a titanium nitride treatment, the cassette is also extremely hardwearing.

More range than 2x

As mentioned earlier, the X-Glide 2 cassette features a 10-50t spread; this results in 500 per cent jump from the highest to the lowest gear, which is a bigger range than even a standard 2x system. Like the 11-speed cassette, it’s machined from stainless steel, with only the biggest cog made from lighter aluminium.

You can’t see it, but the X-Sync 2 chainring features longer, positively raked teeth. As such, they are almost pre-worn, which allows the rollers in the chain to release easier, reducing chainsuck. This design also offers more support for the chain, so there’s less likelihood of it derailing.

SRAM Eagle chainring

Normally with single chainrings you see quite a bit if wear in the winter but the X-Sync 2 chainring has held up amazingly well. It features a longer, positive-rake tooth shape, which allow the rollers in the chain to release easier, while at the same time offering more support and security.

SRAM Eagle derailleur

There are a couple of changes to the derailleur. It now only moves in a horizontal axis, which I reckon protects it from rock strikes and reduces rattle, although SRAM has also increased the clutch force by 20 per cent. The mech hangs on a new B-Bolt, which pivots on an IGUS bushing to eliminate creaking.

There’s a new tool to precisely set the spacing between the upper pulley and cassette sprockets — apparently 50 per cent of all SRAM 1x drivetrains are set up incorrectly in this respect. The best news is, this new tools works with current SRAM rear derailleurs.

The Eagle X01 X-Horizon derailleur is all aluminium (XX1 gets a carbon cage) and like all SRAM mechs features a clutch mechanism and a Cage Lock, so you can swing it out of the way when getting the rear wheel in and out. It’s a pretty long mech though, and while this hasn’t been an issue on my 29in Nukeproof, the cage is really close to the ground on bikes with 27.5in wheels.

SRAM Eagle cranks

If there’s a weakness in Eagle X01 it’s probably the crank. It has carbon arms, a 24mm alloy spindle and SRAM’s handy direct mount interface for mounting the chain ring but it’s not that stiff or durable.

sram eagle

Rock-strewn trails provided a tough test for chain retention on the press launch event

SRAM Eagle long term review

Despite a wet winter and virtually zero maintenance on my part (you can see from the pics that I need a new cable) Eagle X01 has been reassuringly reliable. I’d actually say it’s been pretty boring in this respect.

Shifting was and still is great, there’s no stickiness or play in the derailleur or shifter and, while several of the components are looking pretty battered, they’re all still functioning perfectly.

I’ve had zero chain suck, no chain loss, no reluctance when forcing the gear half way up a steep climb, no stickiness when back pedalling, no chain noise, very little corrosion, no bent link plates, no skipping, nothing to report.

Like I said, boring. But in a good way.

sram eagle

The SRAM Eagle XO1 is boring… in a good way.


If you’re looking for the ultimate 1X drivetrain there are lots of options out there but I reckon Eagle X01 is most evolved 1X system on the market to date – it works perfectly, has a truly versatile and even gearing range and I love the fact that I always have a bail out gear for the end of a ride when my legs are fried. That said I don’t consider it a game changer in the same way as really good suspension or a lightweight set of carbon wheels. I think the main reason it doesn’t feel revolutionary is because it’s so unassuming. Then again truly great products are like that – they just get the job done with minimal fuss.


Chainring:30, 32, 34, 36, 38t