First Look Review : Pete’s SRAM XO Eagle Transmission.

Six years after launching their Eagle drivetrain, SRAM are back with their new Eagle Transmission and Pete has been giving the XO Eagle setup a run out.

The base offering of three new SRAM transmissions, the SRAM XO Eagle setup features direct mount rear mechs, new AXS shifter pods and a narrow-wide cassette all running on a T-type flat top chain.

Pete has spent a few weeks getting to know the new SRAM XO Eagle.

Photos by Pete Scullion.

XO Eagle Rear Mech – £590.00

The rear mech is easily the most striking change. It looks bulky but sits very nicely tucked under the chainstay. This new mech uses the space offered by the SRAM UDH hanger to combine with the axle dropout to bring everything into one in-line setup. The mech now swings off the axle itself rather than a hanger. All this brings the mech closer to the cassette and is a whole load more robust. Overload clutches and its low profile keeps the mech safe from bashes.

Also, every single part of the mech is available as an aftermarket spare. If you do crack the mech body off a rock, you don’t simply have to put the old one in the bin and buy a new one, you can simply swap out the affected part(s), and crack on. You can, if you want, swap your XO outer for a XX skid plate.

Arguably the best part of the mech though is the jockey wheels’ outer teeth are connected to a bushing, so if you get a stick jammed in the cogs, the inner and outer rotate independently until you can clear the jam, vastly reducing the chance of ripping your mech off.

At first glance, the cage of the mech looks twisted and it is. This is by design though. The aim here is to always point the chain at the chainring whatever gear you happen to be in. There’s also no setup screws. The setup steps for the new transmission is pretty straightforward assuming you get everything in place as per the setup guide.

XO Eagle Cassette – £430.00

Very much singing in harmony with the new rear mech is central to the move to direct mount. As the two components now sit closer than ever, the aim is that alignment issues are vastly reduced. At first glance, it looks very much like a SRAM Eagle cassette but look a little closer and there’s plenty that’s new.

Arguably the most important feature is the X-Sync design that has specifically located shift ramps for shifting up and down. You also get less of a jump between cog sizes to better smooth the changes. This is all about pedalling under load. You can tap the shifter to move the chain, but the chain will stay put until it hits these ramps in either direction. The idea here is to not allow the chain to move when it’s detrimental to do so. There will be a fraction of a second change in shift time as a result, but the goal is a more reliable drivetrain.

Nickel plating also drastically reduces the rusting and other corrosion seen on a cassette. On top of all that you still get the massive range offered by the 52t big cog.

XO Eagle Chainset – £430.00 (w/ Power Meter)

SRAM claim that their XO Eagle crank is the best aluminium crank they’ve ever produced.

It’s not too easy to get excited by an forged alloy crank, but they are power metre compatible and like most alloy cranks, should do a solid stint in all conditions.

The cranks come with two bashguards, and you can opt to either leave both on or leave the one your chocolate foot demands. The chain ring now sports a different spider and an 8-bolt mount that allows a drop in weight, and comes in four tooth counts 32-38t.

Merida OneSixty Leaderboard 2023

You can run these with non-T-type Eagle chains.

XO Eagle Shifter Pods – £160.00

This is another part that is backwards compatible with the old AXS groupsets. Whilst the outgoing pods certainly weren’t anything to sniff at, the new two button pod has options to use convex or concave buttons, and features a more adjustable mount to better fine tune where you want it to sit.

Lighter than the older shifters, you can assign which button does what like their older siblings. If you want to, you can flip the shift pod itself on the mount bracket to use the same shifter on both sides of the bars.

XO Eagle Chain – £105.00

The T-type flat top chain is also an instantly recognisable feature of the new setup. The flat top is crucial to the whole X-Sync shifting operation and is, according to SRAM, their strongest chain yet. A PVD coating aims to make it the most hard-wearing chain they’ve made too when it comes to corrosion resistance.

On the trail

The new XO Eagle transmission swapped out the XO1 AXS Eagle setup on my Santa Cruz Hightower test vessel. I’ll start by saying that I am aware that an older drivetrain will feel rougher than a brand new one so any observations are with that in mind.

Noticeable from the get-go was a lack of noise and drag from the new setup. Not that the outgoing XO was noisy or rough-running, but this was something else. Chain ring size was identical on the old setup and the new at 32t.

Shifting was the wonderfully light and consistent feel that typifies AXS shifts. I did notice that my thumb went down to the shift pod rather than in and up compared to the original AXS shifter. This certainly felt more intuitive. The big change was the ability to chose the angle of the pod on the bracket to really get it where I wanted it.

At low cadence, you can definitely notice the change in shift speed on the cassette compared to the XO1 setup, but then low cadence at lower power isn’t where you’re asking much of your drivetrain anyway. Out of the saddle mashing on the pedals is now devoid of the harsh mechanical sound of gears straining up the cassette under load.

Despite riding some seriously, boulder-strewn hills of late the kind that make you wince for your drivetrain, the rear mech hasn’t even come close to showing signs of any interfaces with anything. The times where I’ve not had the time to wash and lube the chain hasn’t left me with a rusty mess of chain and cassette like you might on other setups either. The corrosion resistance was definitely put to the test, and so far, it’s come out swinging.

Whilst SRAM say that the greater force required to move the new cassette will run the AXS battery out faster, I can’t say I’ve had any issues with it. It’s been out in all weathers for fifteen or so big rides and hasn’t needed to be recharged yet.

Any concerns about smacking the mech and either writing it or the frame off have yet to receive a real world test, but with the mech sitting so far underneath the bike, I’d say you’re likely to be getting the terrain pretty close to the frame anyway in order to get at the mech. If you’re that close to the ground already, I’d say you it might well be a case of worrying about writing yourself off more than the bike or its ancillaries.

Whilst direct mount rear mechs are nothing new, the SRAM Eagle offering certainly does work. Shimano went down the Linkglide route for improved reliability and durability, SRAM have come at the same problem from the other end of the spectrum, aiming for the same through their top-tier groupsets. We’ve yet to swing a leg over the Shimano offerings but it appears that the SRAM Eagle transmission has plenty of promise.

You can check out the new SRAM Eagle transmissions over on their website here.