The all-new SRAM Eagle 90 Mechanical Transmission that debuted at the moment is strictly what I used to be searching for in a brand new drivetrain for my tremendous path bike. Final fall, I constructed up a killer lengthy journey mountain bike that might pedal up in addition to it shredded down. It was gonna see quite a lot of abuse. The ridden laborious and put away moist form.
So, I wanted a drivetrain that was: mechanically easy, constructed powerful, but in addition not so costly that it wouldn’t break the financial institution if/once I wanted to switch it. I additionally didn’t need to sacrifice gearing vary or shift precision. And albeit, I didn’t need to have to recollect to maintain it charged.
Final fall, there actually wasn’t something that checked all these containers. Immediately, Eagle 90 Mechanical modified that.
SRAM Eagle 90 Mechanical is reasonably priced, easy & constructed powerful

In late 2024, I acquired ahold of a brand new Scott Ransom frameset to construct up into a motorbike that I might trip probably the most technical trails I might discover. Some days pedaling to the highest of mountains for all-mountain journey rides, different occasions turning back-to-back enduro, freeride & DH laps in bikeparks.
This superb bike pedals like all mid-travel path mountain bike in its decreased journey Climb mode. Then, ‘quantity spacers on the contact of a button’ Ramp Management mode turns it right into a poppy enduro or bikepark shredder. And in full open Descend mode, properly… it descends virtually like a DH bike.


Add in probably the most plush MTB fork I’ve ever ridden with this 180mm double crown Components Belva and a few of the strongest brakes ever made with the Trickstuff Maximas, and this bike shreds.
So, I wished a drivetrain with top-tier shift high quality & vary to match the bike. However on the similar time, one thing that wouldn’t really feel overly treasured. I knew I used to be going to bash my derailleur in opposition to loads of rocks, possibly even crash the bike off one thing silly. So, I refused to place a 480€ GX AXS digital derailleur on a motorbike that was gonna see such abuse. (I don’t even need to take into consideration the 700€ AXS derailleurs that debuted the Full Mount that my body was eager for!)
You see, I’d already barely cracked a GX AXS derailleur final season and struggled to determine what went unsuitable because it step by step stopped shifting. I didn’t desire a repeat of that.


So enter the return of the mechanical derailleur, a lot to my delight.
Mechanical isn’t useless.
Eagle 90 Mechanical 12-speed derailleur


The guts of this new groupset is after all, the all-new SRAM Eagle 90 Mechanical Transmission rear derailleur that launched earlier at the moment.
I already wrote in nice element all the pieces that stands out as necessary in my thoughts, for this comparatively uncommon product launch that’s each genuinely progressive tech AND truly reasonably priced. Counter to most disposable consumerism tendencies, it’s additionally simply serviced and is rebuildable for when you inevitably break some a part of it whereas mountain biking technical trails.


Learn the complete particulars about Eagle 90 Mechanical Transmission and its much more reasonably priced Eagle 70 Mechanical little brother, right here.
It makes me blissful to see this exploded view from SRAM with all of the service elements which can be accessible, since I’m positive I’ll be shopping for a few of these elements down the road to rebuild or restore this factor!


In truth, I’ve solely been driving this new SRAM Eagle 90 Mechanical Transmission for simply over one month now. And sure, I’ve already scraped it up a bit on a few of our tight rocky enduro trails.
Sure, these scrapes are on the non-structural plastic skid plate mounted to the outer parallelogram hyperlink. And sure, it’s a commonplace substitute half accessible from SRAM.
A simple substitute once I harm it a bit extra.
SRAM Full Mount advantages for mechanical too!


Moreover the plain simplicity of mechanical actuation like all basic derailleurs, and the brand new modular rebuild-ability, it’s the hanger-less direct mount (SRAM calls it Full Mount) to your body that units the brand new SRAM Eagle 90 Mechanical Transmission other than all mechanical derailleurs earlier than it.
Whereas many (myself included) lament the lack of the sacrificial derailleur hanger in a crash, there’s no denying that eliminating the hanger eliminates quite a lot of the woes of shifter adjustment. No excessive/low set screws to forestall chains from leaping excessive or off the underside of your cassette. And far simpler shift tuning.
SRAM additionally touts no extra want for a B-screw adjustment, however you continue to have to get the knurled ring friction plate within the right place earlier than you begin. It’s simple to do, and SRAM has an amazing troubleshooting web page to stroll you thru easy methods to do it. However I’ll say that greater than half of the Transmission-equipped check bikes I’ve ridden previously 2 years didn’t have the knurled ring accurately aligned, whether or not for not adjusting them accurately from the beginning in Setup Mode, or simply not greasing & torqueing the T-type derailleur to the complete 35Nm as required.
An all-new stealthy mechanical shifter


A elaborate, rebuildable mechanical derailleur is nothing with out a good shifter to actuate it.
The SRAM Eagle 90 Mechanical Transmission shifter is straightforward and purposeful, if a bit bit heavy and seemingly cumbersome. However actually, it solely appears huge in your hand or on the workbench earlier than set up.
The explanation the Eagle 90 Mechanical shifter appears a bit larger is that SRAM redesigned the shifting mechanism to align the physique of the shifter and the cable exit with the handlebar, just like the Stealth hose routing on all the newest SRAM brakes. As soon as on the bar, the majority of the shifter all however disappears.


The opposite necessary bit about this shifter is that mine shifts 2 gears with one throw of the lever.
That makes its shifting truly faster than Eagle AXS Transmissions, nevertheless it does imply one limitation. You’ll be able to shift one gear at a time underneath full pedaling load. However to shift a number of gears, it’s important to ease again in your pedaling inputs, similar to all earlier non-Transmission/non-LinkGlide drivetrains.
Which means this 2-Click on shifter isn’t appropriate with bikes (which determine on their very own when to cease pedaling). And so there’s a separate Single-Click on mechanical shifter for eMTB setups.
Burly alloy Eagle 90 crankset with metal chainring


The Eagle 90 Transmission crankset is a burly, no-nonsense affair. It’s only a 3D-forged aluminum set of crankarms on a DUB backside bracket spindle. It options an 8-bolt direct mount interface, and comes with a heavy-duty stamped metal chainring.


The Eagle 90 cranks include 2 composite bashguards that bolt on on to the chainring (ring measurement particular). It’s the very same ones that come on X0 AXS and GX AXS T-type cranksets, too.
I used to be fairly excited to have one bash guard connected to my chainring since I virtually all the time bash into rocks & logs with my proper foot ahead. However I forgot that I wouldn’t have clearance as a result of my bike has a mini chainguide up prime.
It’s fairly a disgrace that SRAM doesn’t embrace some provision to area the bash guards out away from the ring, since an enormous variety of bikes embrace related customized higher mini chainguides lately. I would look into determining if there’s a 3D printed spacer so I might nonetheless run certainly one of these?
Precise weights – mechanical shifting


The Eagle 90 Mechanical derailleur weighs in at 390g, with a mixture of aluminum, strengthened composite (seemingly fiber strengthened nylon?), and metal building.


Its matching Eagle 90 shifter weighs one other at 142g, together with its personal band clamp and the uncut shift wire. Not right here on the size, my full-length 4mm shifter outer housing added an additional 45g. That makes for a 577g grand whole to shift mechanically.
I’m a bit stunned that that’s by some means heavier than the 539g shift system weight for T-type GX AXS (a 492g derailleur), the 521g system weight for X0 AXS (474g derailleur), or the 491g mixed weight of XX SL AXS (444g derailleur) from the primary batch of T-type together with their 47g AXS Pod Controllers.
I do know it comes right down to heavier steel elements to align with the cheaper worth level right here. However it hurts a bit to see this heavier than all these wi-fi AXS shift setups when Eagle 90’s weight doesn’t embrace two batteries, a robust little electrical motor, or digital management methods.
I suppose that simply means Dangerholm may have quite a bit to work with when he will get round to tuning certainly one of these for his subsequent extremely customized construct. Do not forget that the unique XX Eagle mechanical drivetrain was usually constructed into the world’s lightest mountain bikes!
Precise crankset weight


The 90 crankset & metal chainring isn’t precisely gentle both, at 808g for 165mm arms with bash guards, in comparison with 733g for a similar GX setup. Though, I did get my cranks right down to 728g by eradicating the two units of 40g bash guards. I’d have beloved to have them, in the event that they didn’t conflict with my bike’s mini chain information, which took purposeful precedence.
Weight-wise, the remainder of the SRAM Eagle 90 Mechanical groupset reuses a number of of the identical elements straight from GX AXS, together with the 443g 10-52T T-type cassette, the 285g FlatTop chain, and in my case on this bike, a 76g PressFit DUB backside bracket.
First Impressions


My first thought was this can be a fairly good feeling drivetrain for its $670 / 730€ full groupset pricetag.
It might even be extra reasonably priced than that too, in the event you had been upgrading a present SRAM mountain bike groupset. Purchase a $190/205€ 90 derailleur, $50/55€ 90 shifter, $30/35€ 70 chain, a $215-250/240-300€ 1275 or 1270 cassette relying in your present wheels, and $18-20/20-22€ 70 or 90 chainring relying in your present cranks. A minimal improve price of $503/55€.
(It’s wild that the costliest factor on this new group is the carry-over T-type cassettes from GX or S1000, proper?)
Subsequent to note was how easy it was to place this on the bike.
With no set screws and no derailleur hangers, you simply bolt this pet to your bike and go. SRAM calls it “put together, cling, tighten”. Their app will show you how to set your chain size, otherwise you simply do it old fashioned like me. Then you definitely cling the derailleur unfastened in its setup pin place, join the chain, launch the cage spring, and tighten the derailleur into place. Then, merely pressure the shift cable and tighten that down, and easy-peasy derailleur adjustment with the shifter’s barrel adjuster.
It was weirdly fast and simple. As soon as on the path, it solely required a number of quarter turns of that barrel to make shifting good.
Actually the simplest mechanical derailleur setup I’ve put in within the final 30 years.
On Path Driving Ideas


Out on the path, it simply works. Shifts are crisp, with constructive lever suggestions. And it was simple to fine-tune.
Eagle 90 Mechanical simply does its job, delivering the identical shifting and driving really feel as GX AXS Transmission. It feels the identical as a result of you’ve got the identical chainring, flattop chain, and the very same XS-1275 Transmission cassette with the identical shift factors and ramps.
The largest distinction in comparison with the digital T-Sort drivetrains is that the Eagle 90 setup right here on a pedal-powered bike truly shifts faster, with extra constructive shift suggestions at your thumb. Since mine isn’t an eMTB-approved shifter, I get 2 shifts with one throw of the lever, which I actually admire once I’m about to rapidly go up hill and need to dump a bunch of gears.


After which, there’s the sturdiness – each actual and perceived.
After wheels most likely, the rear derailleur is the one part that sees probably the most abuse, how and the place I trip. Virtually each season, I’ve to switch an MTB derailleur cage, or a minimum of bend one again into form. It’s reassuring that if I do break this factor, will probably be simple to get substitute elements for it. And even when I needed to change the entire thing, it’s not all that costly both.
Parting ideas on Eagle 90 Mechanical Overview


Look, the brand new SRAM Eagle 90 Mechanical Transmission isn’t completely good. I’d like to see the derailleur and shifter to every be a bit lighter. There’s no cause in addition to market positioning that SRAM couldn’t have made this lighter than a GX AXS shifter/derailleur combo, what with no batteries or electrical motors to account for.
And realistically, Eagle 90 would pair very well with an XX crankset for extra weight financial savings and a extra premium really feel.
However what makes this groupset nice is so laborious to argue with: no batteries to cost, no firmware to maintain updated, and way more reasonably priced pricing. Simply easy basic cable-actuated shifts. A stable direct Full Mount set up that requires little or no setup adjustment. And now with a strong modular building that must be simple to maintain working for years to come back!
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