Sram Eagle 70 & 90: The transmission shifting for little money shifts mechanically

Since the introduction of UDH (Universal Derailleur Hanger) and in the next step of the changeover to the stable transmission drivetrain, Sram only uses electronic shifting. However, if you wanted to ride the current T-Type drivetrain, you had to invest upwards of 1300 euros for a GX AXS Transmission groupset. Now the shifting giant is expanding its programme to include the two affordable alternatives, which fit both MTBs with and without a motor.

Sram Eagle 70 & 90: Mechanical transmission

With the Eagle 70 and 90, Sram is expanding the transmission cosmos with two favourable Gearsticks. Both also rely on the stable full-mount connection to the frame, which, like all Transmission groupsets, requires UDH compatibility. The two new groupsets should not only be extremely robust, but also easy to repair. All individual parts of the rear derailleur are available separately for retrofitting. As with the Transmission AXS groupsets, both derailleurs are designed to change gears reliably even under load. Precise gear changes are guaranteed even with the additional drive power of an E-MTB.

Price from 545 euros

In order to keep the price as low as possible, both groupsets dispense with electronics and are controlled classically by cable. Due to the changed gear ratio, however, they are not compatible with the current mechanical 12-speed groupsets from Sram. However, all T-Type components are compatible with each other. With a price of just 730 euros, the Eagle 90 groupset (rear derailleur, shifter, crank, bottom bracket, cassette, chain) is significantly below the level of a GX AXS transmission. The Eagle 70 even comes in at around €545 and is therefore slightly more expensive than a Sram NX Eagle groupset. From now on, the Eagle 70 is the cheapest way to ride a transmission drivetrain.

>> Sram GX Transmission: Without cables - is it worth switching to electric gears?

Simple setup

Despite the absence of electronics, the Eagle 70 and 90 have also been designed with a simple setup in mind, similar to the more expensive Transmission groupsets. The two new rear derailleurs therefore also do not require any adjustment screws and can be fine-tuned simply by pre-tensioning the Bowden cable. Sram summarises the installation process under the slogan: "Prepare, fit and tighten". To engage the setup gear during installation, all you need to do is insert an Allen key into the rear derailleur.

>> Troubleshooting T-Type gears: Correctly setting the Sram Eagle transmission

Eagle 90 in detail

In terms of weight, the Eagle 90 rear derailleur weighs 389 grams, the shifter 132 grams and the 170 mm crank with steel chainring 822 grams without bearings. The Eagle 90 uses the same cassette (443 grams) and chain (285 grams) as the GX AXS T-type. The Eagle 90 cranksets are made of forged aluminium and come with crank arm lengths in 5 mm increments from 175 to 155 mm for normal bikes and down to 150 mm for E-MTBs.

The components of the Eagle 90

• Eagle Transmission XS-1275 cassette, 300 Euro, 443 grammes
• Eagle 90 Transmission rear derailleur, 205 euros, 389 grams
• GX Eagle Transmission Flattop chain, 60 euros, 285 grams
• Eagle 90 Transmission crankset, 170 euros, 822 grams
• Eagle 90 Transmission shifter, 55 euros, 132 grams (all weights were weighed by the rider)

The components of the Eagle 70

• Eagle Transmission XS-1270 cassette
• Eagle 70 Transmission rear derailleur, 135 euros
• Eagle 70 transmission flattop chain, 35 euros
• Eagle 70 Transmission crankset, 100 Euro
• Eagle 70 Transmission shift lever, 35 Euro

Sram Eagle 70 & 90: First ride impression

The function of a classic gear shift with Bowden cable depends largely on how much friction there is in the system. The routing of the outer casing therefore has a decisive influence on the required manual force and the precision of the gear changes. Every additional radius, every tight loop in the outer casing increases friction.

Especially on modern bikes with internally routed cables, sometimes even through the headset or even handlebars, the routing may not be optimal. Wireless systems such as an AXS have a clear advantage here. On our test bike, a Giant Trance, the cable exit is located at the bottom of the chainstay. The input on the new rear derailleur is right at the top, which is why the outer casing describes a tight curve.

Due to less than optimal cable routing, the thumb force required to change gears was quite high. Nevertheless, the Eagle 90 shifts precisely and reliably. Similar to the expensive AXS Transmission groupsets, the new rear derailleur also parried gear changes under high loads. Thanks to the tooth profile (X-Sync design), the chain is reliably guided and only changes sprockets safely and in a controlled manner at the derailleur points. In some cases, however, the chain only climbs onto the next sprocket with a minimal delay until the next shifter releases the chain.

Due to the lack of end stops on the rear derailleur, the rear derailleur continued to jerk minimally when the thumb was pressed, even when the largest sprocket was reached. However, we were unable to provoke the chain to drop. To make shifting easier, two gears can be shifted at once; shifting harder is always gear by gear. On the special e-bike version, only one gear can be shifted more easily at a time. On another test bike with the Sram Eagle 70, the manual force was significantly lower, as the outer casing ran into the rear derailleur without a strong arc.