SRAM has expanded its renowned Transmission, or T-Type drivetrain lineup with the addition of two new mechanical groupsets: Eagle 90 and Eagle 70. These new additions aim to deliver the robust performance and reliability associated with SRAM's electronic offerings, now tailored for riders who prefer the tactile feel and simplicity of mechanical shifting, as well as a lower price point.
Until now, SRAM's Transmission groupsets were electronic only. We love the wireless AXS groupsets - they're fast shifting, easy to install, and make for a very clean aesthetic with no cables, but the price of entry is admittedly high, and electronics are not for everyone. Eagle 70 and 90 are here to change that, bringing T-Type reliability and shift quality down to a mechanical price point.
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Eagle 70 & 90 Transmission: Modular and Rebuildable
The Eagle 90 and 70 Transmission groupsets stand out as the world's first mechanical groupsets featuring SRAM's Full-Mount attachment system. This design enhances durability and ensures precise shifting even under maximum power. One of the things we love about T-Type derailleurs is their modular, rebuildable, design, and this carries over to Eagle 70 and 90.
The Eagle 90 derailleur is totally rebuildable, with all spare parts available, including parallelogram and knuckle parts. The Eagle 70 derailleur is rebuildable to a lesser extent, but skid plates and cages are available, and easily replaced, extending the lifespan of your drivetrain almost infinitely.
How Does Eagle 70 & 90 Work?
Based on SRAM's Full-Mount design, Eagle 70 and 90 derailleurs are compatible with UDH frames only. Full-Mount sandwiches the frame between the mounting plates on the derailleur and pivots on a big bushing. The frame's axle secures the whole assembly, meaning the derailleur pivots around the axle, and uses this as a reference point. This makes the derailleur super stiff, and makes for an extremely precise shift. This is the basis for all T-Type derailleurs, making them super robust and reliable.
Full-Mount means that Eagle 70 and 90 derailleurs do not have a high or low limit screw, much like their AXS counterparts, making setup easier and quicker, and with much less margin for error. The "Prepare, Hang, Tighten" procedure adds an extra "Route" step to the end, for the addition of the shift cable, the only real manual adjustment being a turn of the barrel adjuster for cable tension. Setup is otherwise the same, making for a pretty much plug and play experience.
Eagle 90 uses the same XS-1275 cassette and flat top chain as GX Transmission, so as you'll imagine, the shift mapping is the same, allowing for the same shifting under load. SRAM says that the harder you pedal, the smoother it shifts. Eagle 70 introduces its own specific chain.
Eagle 70 and 90 both get the same 10-52t range you'll find on the higher end groupsets, with the 90 using that GX cassette for XD driver body, whereas the 70 uses the XS-1270 cassette released with SRAM S1000, that fits a splined HG freehub, but retains that small 10t sprocket thanks to it being integrated with the lockring. Gears 8-12 are also a replaceable part on this particular cassette.
Eagle 70 it seems will mostly be OEM, whereas while 90 will be specced OEM on a lot of bikes, it's also available aftermarket as a complete groupset.
What's in a Groupset?
The Eagle 90 groupset is comprised of a cassette, chain, derailleur, shifter, cranks, and chainring, of which the latter four are all brand new, the same being true of Eagle 70. Cassettes and chains carry over from other existing T-Type groups, and as with most SRAM products, the entire T-Type ecosystem is cross-compatible.
The Eagle 90 crankset is forged aluminum and incorporates a DUB spindle with a 55mm chainline. It offers crank arm lengths ranging from 155mm to 175mm, accommodating various rider preferences. Additionally, the 8-bolt chainring interface is steel for longevity, and compatible with removable bash guards, providing extra protection on rugged trails.
For shifting, Eagle 90 employs a double-click T-Type Actuation mechanical shifter, enabling up to two shifts at once. This feature ensures smooth and reliable gear changes, even under load. There is also a single-click ebike option available. Both shifters fit an MMX stealth mount, and the Eagle 70 shifter has an option for an integrated band clamp, and again there's a single-click option availale.
Who Is Eagle 70 And 90 For?
We're expecting to see Eagle 70 and 90 come as stock spec on a lot of bikes going forward - essentially it will be replacing NX and GX Eagle on UDH-compatible bikes, bringing reliable and robust mechanical shifting to lower tiered bikes. We know that electronic shifting also isn't for everyone, so for those that want T-Type without the batteries, there's the Eagle 90 full groupset.
Eagle 90 Installation Report
We've currently installed our first Eagle 90 derailleur and shifter onto a bike that was running GX Transmission. Install really is very similar, with the same "prepare-hang-tighten" steps, with the inclusion of a 4mm or 5mm hex key to get the derailleur into the setup cog and the addition of a "route" step. There are no limits to set, and so long as you follow the steps to the letter, you can't really go wrong. Cable tension is the only variable part of the puzzle, and is as simple as turning the barrel until the shifting feels good.
We're yet to test Eagle 90 on-trail, so stayed tuned for a longer-term report.
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