The most important facts in brief

The biggest advantages of transmission technology are the direct mounting of the rear derailleur on the bike frame, the many replaceable individual parts and the robust design. There are people who don't want electronic shifting: they just want to go biking without having to think about whether the rear derailleur or shifter still has power. Sram has listened to these people and presents the Eagle 90 (and the Eagle 70), a transmission groupset that works with a classic cable. Sram offers them as a complete groupset and, logically, also as individual components. If you want to bring your existing mechanical groupset up to date, you can also retrofit just the cassette, rear derailleur and shifters and install a flattop chain. It is not absolutely necessary to replace the crank and chainring. The cassette is the XS-1275 model introduced with the AXS transmission (which comes with the GX Transmission group was introduced) for use, there is no specific version for the Eagle 90.

First impression

The massive rear derailleur looks just as robust as that of the AXS versions. The black and silver materials look high-quality. The gearshift also differs from the previous ones. The design is more angular and the levers are positioned slightly differently. The workmanship appears solid and predicts a long service life.

In use

For quick and uncomplicated installation, it is advisable to read the instructions carefully and then follow them step by step. Then you'll be able to install the derailleur group very quickly. Anyone who has the feeling that they can simply screw on the rear derailleur, lay the cables and then make fine adjustments is mistaken. Transmission technology does not require the usual A and B bolts. So it's back to square one and consult the instructions.

The gearshift takes some getting used to, the positions of the two levers are not the same as before. The shifting feel is also different. A touch less precise and it seems as if the lever travel when shifting up is longer than with the GX Eagle groupset, which is roughly the same price. This has no effect on the shifting performance, it's just a different feel when operating. When shifting up, two gears can be changed at once. This is barely noticeable under light load and always crisp with acoustic feedback when more pedal pressure is applied. When shifting down the gears, the shifting process is just as precise as with the existing mechanical shifting groupsets.

As with all shifting systems, the shifting quality varies depending on the terrain and pedal pressure. Shifting steeply uphill under full load does not sound very smooth, even with the Eagle 90. If the gears are changed on flat terrain, with momentum and without great pedaling force, it is very smooth and barely noticeable.

The shifting group test was carried out on a "Yeti SB160" enduro bike. Even in the roughest terrain and on very steep climbs - with shifting under maximum load - no problems were encountered. There was no need to readjust the gears. There was also never any unwanted rock contact with the rear derailleur, which would have forced this. The chain tension was sufficiently high so that no unwanted chain slap occurred and the bike was as smooth as ever.

During the test period, six rides were also undertaken on an e-bike equipped with the Eagle 90 ex works. There, the shifting group presented a slightly different picture. Due to the higher chain pull caused by the motor support, the gear changes are barely noticeable in some cases. You also need to press the shift lever more firmly to trigger the gear changes. But even with more tension on the chain, the Eagle 90 masters E-bike use without any complaints.

Conclusion

The "Eagle 90 Transmission" groupset offers a carefree package at a fair price. It is not the lightest, but boasts a robust construction and the advantage that many individual parts can be replaced in the event of a defect. In addition, the group is always ready for use and there is no need to worry about charge levels. As far as function is concerned, there is nothing to complain about.

Recommendation

If you want to convert an Eagle 90 rear derailleur to AXS wireless technology at a later date, you can buy a corresponding upgrade kit. However, this costs almost as much as the entire groupset itself.

Price: CHF 725.00 / EUR 645.00

Manufacturer

www.sram.com