SRAM Eagle 90 Mechanical Transmission review

DrivetrainReview

by Ben Haworth March 27, 2025 3

Look Ma, no batteries! SRAM Eagle 90 Transmission is cable actuated but T-Type full-mount interface (replaces your UDH hanger). Here’s our early verdict…

• Brand: SRAM
• Product: Eagle 90 Mechanical Transmission
• Price: £655.00 (rear mech, shifter, crankset, chainring w/ guards, chain, cassette)
• From: ZyroFisher
• Tested by: Benji for a month

Pros

• Quicker to shift than AXS version
• Always executes the shift
• Rebuildable

Cons

• Occasional rough feeling/sounding gear changes
• Not appreciably smaller or lighter than the electronic mech

This is SRAM’s first cable actuated T-Type drivetrain, sorry… transmission. It uses the full-mount interface (clamps either side of your frame dropout) and installs via the same prepare-hang-tighten installation that no longer requires fiddling with stop screws or B-tension screw etc.

But yes, ‘all’ you have do is work out how many chain links your bike requires via the SRAM AXS app or webpage and follow a set but simple order of sequences and you’re sorted. Well, as Eagle 90 still requires trad cable inner and outer, you do have to do some indexing via a trad cable adjuster barrel on the shifter.

Although it requires a bit more than bolt-it-on-and-pedal-off, T-Type is simpler and quicker to setup than rival brands’ cable drivetrains. I personally still don’t think it’s a major selling point for experienced cyclists though. It’s T-Type’s ability to shift under load – and it’s general extra robustness – that is the system’s USP in my opinion.

Speaking of which, whilst it doesn’t/can’t have the move-out-of-the-way-and-return impact re-action of the electronic mech, it does retain the ability to rotate backwards from fore-aft impacts (much like pre-T-Type first generation AXS mechs).

Robustly speaking, SRAM says that the Eagle 90 mech is “the most rebuildable derailleur ever”. The replacement kits in full:

• B-Knuckle replacement kit
• P-Knuckle replacement kit
• Skid plate, outer and inner link replacement kit
• Cage and damper assembly kit
• Cage without damper replacement kit
• Inner Cage replacement kit
• Pulley replacement kit
• Bushing replacement kit
• Cable & housing replacement kit

Eagle 90 uses the same 12-speed 10-52T cassette design and flat-top chain too (literally the XS-1275 cassette and GX T-Type chain that launched with GX AXS T-Type last year). In terms of cross-compatibility, the new SRAM Eagle 70 (and the cheaper SRAM Eagle 70 stuff) will work with anything ‘T-Type’ that is relevant ie. chains, cassettes and chainrings.

The brand new bits of SRAM Eagle 90 are the rear mech, the shifter(s) and the crankset. The shifter comes in two versions: double-clicker for normal bikes and single-clicker for e-bikes.

The shifter has been ‘Stealth’ designed ie. its cables exit in parallel to the handlebars, like SRAM’s similarly ‘Stealth’ brakes. As mentioned, the shifter comes in two versions: a regular one that can execute two-shifts with one sweep, and an e-bike shifter that just shifts one gear at a time.

Because I’m a baddie I tried using the regular multi-shifter on an e-bike (see pictures) and didn’t have a problem. But it’s not something that SRAM reommend or indeed will warranty.

The shifter is a much neater and crsiper feeling than mid-level SRAM shifters of yore. There’s much less free play in the downshifter paddle. And the paddles themselves just feel better designed ergonomically.

The crankset is available in arm lengths in 5mm increments from 175mm to 155mm, with e-bike crank assemblies being offered down to a dinky 150mm. There’s 8-bolt chainring compatibility, the Eagle 90 crankset includes stamped steel T-Type chainring with removeable bashguards.

On the trail

On the trail, I’ll be honest, there isn’t much to say about SRAM Eagle 90. Apart from the fact that it just… works. Because the mech moves when your thumb tells it too, the shifting is quickler to happen compared to the electronic AXS Transmisisons. It does mean that there’s the occasional metallic clank sounds and rough feel through the pedals when shifting but it still shifts. It doesn’t hang up, or tick-tick, or jerk. It just shifts.

SRAM claim that Eagle 90 offers the “best mechanical shifting under load” and I’d agree with that. Only time will tell how it fairs in terms of robustness, reliability and maintenance. I’ll keep pedalling. Stay tuned. In the meantime, if you have any questions, ask in the comments below.

Some numbers:

SRAM Eagle 90 weights:

• Mech 395g
• Crankset 825g
• Shifter 135g
• Cassette 445g
• Chain 285g

SRAM Eagle 90 UK prices:

• Mech £185
• Crankset £150
• Shifter £50

Review Info

Ben Haworth

Orange Switch 6er. Stif Squatcher. Schwalbe Magic Mary Purple Addix front. Maxxis DHR II 3C MaxxTerra rear. Coil fan. Ebikes are not evil. I have been a writer for nigh on 20 years, a photographer for 25 years and a mountain biker for 30 years. I have written countless magazine and website features and route guides for the UK mountain bike press, most notably for the esteemed and highly regarded Singletrackworld. Although I am a Lancastrian, I freely admit that West Yorkshire is my favourite place to ride. Rarely a week goes by without me riding and exploring the South Pennines.

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