World premiere: Sram launches its first e-mountainbike groupset - the EX1

Until now, e-mountainbikes have had to make do with conventional drives. However, the parts are not able to cope with the additional weight and drive power in the long term. Sram is now the first manufacturer to respond and is presenting the world's first shifting group and brake for e-mountainbikes - the EX1, the result of a different approach and developed from scratch.

The heart of the EX1 groupset is the E-BLOCK^™ cassette. This is designed to create an optimum gear range for e-mountain bikes and to increase the service life of the battery and components. The highlight of the cassette: it comes with just eight sprockets with 11, 13, 15, 18, 24, 32, 40 and 48 teeth. This makes the cassette narrower than a 10-, 11- or 12-speed cassette, but allows the chain to be made wider and more robust so that both last longer. The E-BLOCK^™ cassette also sits on a normal body and not on an XD, as a ten-speed sprocket is not required for e-mountain bikes. Thanks to the focus on the "climbing sprockets", which are better suited to the power development of the motor, the battery should also last longer.

Good shifting characteristics are also at the heart of the EX1. However, its trigger gearshift differs technically from its "normal" brothers. Only one gear can be shifted up at a time and not several with a single press. When shifting under load, the chain and cassette are less heavily loaded with just one sprocket jump.
The EX1 changer comes in the robust X-HORIZON design familiar from the XX1 and X01 changers. However, the clutch, the cage and the changer rollers have been specially redesigned for the 48 sprocket.

Crank, chainrings and stoppers

Sram describes its EX1-E crank as lightweight, durable and stiff, which is specifically designed for mid-drive motors such as Bosch, Brose and Yamaha. Above all, the crank is designed to withstand the higher torsional forces. It is made from aluminum and is available in 170 and 175 millimetre lengths.

No chainring, no drivetrain: As with the standard 1x11 drivetrains, Sram also offers X-SYNC^™ technology for chainrings of the EX1 groupset. These are available with 14, 16 and 18 teeth for Bosch, and with 34 teeth for Brose motors. The front sprockets for Bosch systems are made of aluminum, while the "Brose chainring" is made of steel.

When you accelerate, you also have to brake again at some point, and Sram's engineers have also thought about this issue. The result is the Guide RE brake. This consists of the Guide-R brake levers and the powerful four-piston caliper of the Code, which originates from the Gravity range. This should enable the Guide to better control the larger mass of the bike, regardless of the terrain, whether downhill or uphill, and also with sustained braking power.

www.sram.com