The all-new SRAM Eagle 90 Mechanical Transmission that debuted in the present day is precisely what I used to be on the lookout for in a brand new drivetrain for my tremendous path bike. Final fall, I constructed up a killer lengthy journey mountain bike that would pedal up in addition to it shredded down. It was gonna see a number of abuse. The ridden exhausting and put away moist sort.
So, I wanted a drivetrain that was: mechanically easy, constructed powerful, but additionally not so costly that it wouldn’t break the financial institution if/after I wanted to exchange it. I additionally didn’t wish to sacrifice gearing vary or shift precision. And albeit, I didn’t wish to have to recollect to maintain it charged.
Final fall, there actually wasn’t something that checked all these bins. At present, Eagle 90 Mechanical modified that.
SRAM Eagle 90 Mechanical is inexpensive, easy & constructed powerful
In late 2024, I bought ahold of a brand new Scott Ransom frameset to construct up into a motorbike that I might experience essentially the most technical trails I might discover. Some days pedaling to the highest of mountains for all-mountain journey rides, different instances turning back-to-back enduro, freeride & DH laps in bikeparks.
This wonderful bike pedals like all mid-travel path mountain bike in its lowered 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, nicely… it descends virtually like a DH bike.
Add in essentially the most plush MTB fork I’ve ever ridden with this 180mm double crown System 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 valuable. 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 wish 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 mistaken because it regularly 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 center of this new groupset is in fact, the all-new SRAM Eagle 90 Mechanical Transmission rear derailleur that launched earlier in the present day.
I already wrote in nice element every thing that stands out as vital in my thoughts, for this comparatively uncommon product launch that’s each genuinely progressive tech AND really inexpensive. 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 total particulars about Eagle 90 Mechanical Transmission and its much more inexpensive Eagle 70 Mechanical little brother, right here.
It makes me glad to see this exploded view from SRAM with all of the service elements which are out there, since I’m positive I’ll be shopping for a few of these elements down the road to rebuild or restore this factor!
In reality, 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 customary alternative half out there from SRAM.
A simple alternative after 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 removes a number 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 appropriate place earlier than you begin. It’s simple to do, and SRAM has an incredible troubleshooting web page to stroll you thru find out how 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 total 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 little bit bit heavy and seemingly cumbersome. However actually, it solely seems to be huge in your hand or on the workbench earlier than set up.
The rationale the Eagle 90 Mechanical shifter seems to be 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 vital bit about this shifter is that mine shifts 2 gears with one throw of the lever.
That makes its shifting really faster than Eagle AXS Transmissions, nevertheless it does imply one limitation. You possibly can shift one gear at a time underneath full pedaling load. However to shift a number of gears, you must ease again in your pedaling inputs, similar to all earlier non-Transmission/non-LinkGlide drivetrains.
Which means this 2-Click on shifter shouldn’t be appropriate with bikes (which resolve 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 hooked up 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 high.
It’s fairly a disgrace that SRAM doesn’t embody some provision to house the bash guards out away from the ring, since an enormous variety of bikes embody comparable customized higher mini chainguides nowadays. I’d look into determining if there’s a 3D printed spacer so I might nonetheless run one in every of these?
Precise weights – mechanical shifting
The Eagle 90 Mechanical derailleur weighs in at 390g, with a mixture of aluminum, bolstered composite (probably fiber bolstered 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 little bit shocked that that’s one way or the other 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 all the way down to heavier metallic elements to align with the cheaper value level right here. Nevertheless it hurts a bit to see this heavier than all these wi-fi AXS shift setups when Eagle 90’s weight doesn’t embody two batteries, a strong little electrical motor, or digital management techniques.
I assume that simply means Dangerholm can have rather a lot to work with when he will get round to tuning one in every of these for his subsequent extremely customized construct. Keep in mind that the unique XX Eagle mechanical drivetrain was typically 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 all the way down to 728g by eradicating the two units of 40g bash guards. I’d have liked 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 inexpensive than that too, should 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 most costly 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, grasp, tighten”. Their app will provide help to set your chain size, otherwise you simply do it old style like me. Then you definately grasp 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 straightforward. As soon as on the path, it solely required a number of quarter turns of that barrel to make shifting good.
Definitely the best mechanical derailleur setup I’ve put in within the final 30 years.
On Path Using 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 may have the identical chainring, flattop chain, and the very same XS-1275 Transmission cassette with the identical shift factors and ramps.
The most important distinction in comparison with the digital T-Sort drivetrains is that the Eagle 90 setup right here on a pedal-powered bike really 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 recognize after I’m about to shortly go up hill and wish 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 only part that sees essentially the most abuse, how and the place I experience. Virtually each season, I’ve to exchange 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 alternative elements for it. And even when I needed to exchange the entire thing, it’s not all that costly both.
Parting ideas on Eagle 90 Mechanical Evaluate
Look, the brand new SRAM Eagle 90 Mechanical Transmission isn’t solely good. I’d like to see the derailleur and shifter to every be a bit lighter. There’s no motive apart from 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 exhausting to argue with: no batteries to cost, no firmware to maintain updated, and far more inexpensive 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 return!
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