SRAM has launched two new Eagle Transmission drivetrains: the Eagle 90 Transmission and the Eagle 70 Transmission. They are slated to be the first mechanical groupsets to use a Full Mount interface rather than a derailleur hanger, and both will have e-bike specific options. A full Eagle 90 groupset costs £655, whereas the Eagle 70 will be more OEM-focused so expect to see it on some newer bikes, but with the option to buy individual components aftermarket.

Guy Kesteven has a full review of SRAM Eagle 90 Transmission where you can find out how it rides, or keep reading here to discover the spec and prices of both new groupsets… and whether or not you can stand on one.

The Eagle 90 Transmission derailleur is designed to be fully rebuildable

It’s been a few years since the radical hanger-less electronic T-Type groupsets were initially launched, so it’s good to see a mechanical offering centred around the same principles. And, although it’s still reasonably expensive, it’s far less than the AXS T-Type combination you can spend £2k on. So, what are the big differences (besides, you know, the gear cable) and will they be worth splashing the cash on?

New SRAM Eagle Transmission groupsets need to know:

• Two new systems launched: Transmission 90 and 70
• Both use Full Mount system instead of derailleur hanger
• All parts compatible with other T-Type components, AXS or mechanical
• UDH frame compatibility only
• £655 for the full Eagle 90 groupset
• Eagle 70 groupset OEM as full set, individual parts available to buy

Each groupset offers two shifter variations – single or double-click. Which one you choose depends on whether you’re riding an acoustic or electric bike

What’s new?

Broadly speaking, the two transmissions feature much of the same trickle-down technology as the electronic versions, and includes options to work with e-bikes specifically, too. The Eagle 90 is a slightly more premium set-up, and available in its entirety aftermarket. Whereas, the Eagle 70 is OEM-focused, with only individual components available to purchase after the fact. Of course both drivetrains are designed to work with the UDH dropout standard, but seeing as 99% of modern MTBs use this design, it shouldn’t be a problem.

New for the Eagle mechanical groupsets is is the cable routing architecture, which can route the cables so they are parallel to the handlebars, which can apparently help when pairing with certain SRAM brakes. Each groupset offers two types of shifter: a single-click option specifically for eMTB and double-click for conventional bikes.

The flat top chain is also eMTB compatible

Eagle 90 Transmission

Dubbed by SRAM as the “world’s best mechanical shifting,” the Eagle 90 Transmission drivetrain has plenty to live up to. It uses the same Full Mount design as its AXS counterparts, and SRAM claims the Eagle 90 derailleur is the “most rebuildable derailleur ever,” with the brand offering rebuild kits and skid plates for if/when you do need to rebuild it. It’s priced at £180, which isn’t cheap, but making it repairable means you won’t have to replace the entire thing if/when you crash.

The cranksets are crafted from aluminium and the lengths range from 155mm to 175mm for manual bikes. For eMTB cranks, they can be offered down to 150mm. There’s a stamped steel chainring for durability or aluminium for less weight to choose from, as well as two independently removable bashguards that are chainring size-specific.

eMTBs powered by SRAM Powertrain, Bosch or Brose can use the new cranks

eMTB cranks are available for SRAM Powertrain, Brose or Bosch equipped bikes and come in 155-170mm crank length options.

The XS-1275 cassette offers a 520% range with larger 38 and 44 tooth cogs for better gear stepping compared to other 10-52 Eagle cassettes, and uses X-Sync tech for better shifting performance under load. This is topped off with nickel plating, which apparently leads to a quieter and more durable cassette. And finally, the new chain is claimed to be the strongest SRAM has ever made – and features a flat top profile and is approved for eMTB use.

The full Eagle 90 Transmission costs £655 and comes with:

• Eagle Transmission XS-1275 Cassette
• GX Eagle Transmission Flattop Chain
• Eagle 90 Transmission Derailleur
• Eagle 90 Transmission Crankset
• Eagle 90 Transmission Shifter

The infamous picture from a few years ago, re-done with the new mechanical groupset

Eagle 70 Transmission

Reliable, durable, simple. That’s what the Eagle 70 is aiming to be. SRAM says it has more of an OE focus but maintains aftermarket availability on individual components, so riders can buy a new bike equipped with the 70 but then upgrade to the 90 if they so wish.

The rear derailleur costs £120 and uses the same Full Mount design as the electronic counterparts, but at a more wallet-friendly price point, and features replaceable skid plates like the GX, X0 and 90 options but not as rebuildable as those models.

The crankset features a 3-bolt chainring compatibility and stamped T-Type chainring with optional bashguards. They’re available in 165, 170 and 175mm lengths, and for eMTB, you get 160, 165 and 170mm options and ISIS spindle interface compatibility.

The Eagle 70 is OEM-focused so expect to see it on some new bike models

The 10-52t cassette is finished in a black nickel chrome, and gears 8-12 are replaceable in a cluster. It also features X-Sync tech like the 90 cassette, too, but it’s a little heavier overall and focuses more on durability than weight.

The chain is rated for eMTB applications as well as acoustic, and uses a flat top profile and smooth-shift bottom profile just like the Eagle 90 chain.

And finally, the Eagle 70 comes with direct mount chainrings, with options in a 30-34t range, and silver or black colourways (but with different bolt requirements for each).

Although you can’t buy the Eagle 70 as a groupset in its entirety, you can buy replacement parts, including:

• Eagle Transmission XS-1270 Cassette
• Eagle 70 Transmission Flattop Chain
• Eagle 70 Transmission Derailleur
• Eagle 70 Transmission Crankset
• Eagle 70 Transmission Shifter

The Eagle 70 and 90 drivetrain components will be available to purchase from retailers in March 2025.

sram.com/en/sram