SRAM EX1 e-bike MTB group 1x8
If you want to move your e-bike sportily off-road, you can quickly push your drivetrain to its limits. Improper gear changes when shifting under load and chain breaks can be the result. The engineers at SRAM have tackled this problem and have launched the EX1, a shift group specifically for the requirements of e-bikes. With a wide range cassette with only 8 gears, you can make perfect use of the extra power of the engine support when accelerating without having to shift too many gears. Equipped with the proven 1-speed technologies from SRAM, you can shift gears intuitively under load without fear of chain drops or material damage.
The EX1 rear derailleur builds on SRAM's proven X-Horizon design. This special rear derailleur parallelogram limits the movements of the rear derailleur to the horizontal axis and reduces ghost shifting to a minimum while increasing the shifting force. The EX1 rear derailleur has been optimized for use with the EX1 E-Block 11-48 cassette. In this combination, even e-bike typical switching operations with high torque and low cadence succeed without any problems. The X-Sync pulley wheels with their optimized narrow-wide tooth profile fit perfectly into the EX1 chain and, in conjunction with the Type 3.0 vibration damping, prevent the chain from jumping off. The tension pulley has been designed with 14 teeth extra large, which ensures a smoother and less resistant running of the chain. To simplify rear wheel removal, the EX1 rear derailleur is equipped with a cage lock, which can be used to relax the rear derailleur cage.
Trigger shift lever
The EX1 8-fold trigger switch was developed for precise and defined switching processes. This is guaranteed by the proven X-Actuation technology from SRAM, which ensures constant switching performance across the entire cassette. To prevent switching, only single gears can be shifted with the EX1 trigger, which in combination with the EX1 8-speed wide-range cassette is completely sufficient. For a tidy cockpit and best ergonomics, the EX1 Shifter can be installed with the SRAM Matchmaker or Matchmaker X.
The heart of the EX1 group is the XG-899 8-speed cassette. Your E-Block technology is a fundamental new development for derailleur gears. Similar to narrow-wide teeth on chainrings, the chain has a fixed position on the sprockets of the cassette and works with either the inner or outer plates of the chain. In spite of the large gear jumps of the wide range cassette, this enables optimal shifting performance in both directions with high torque. With 11-48 teeth, the cassette has a gear ratio range of 436%, which means you are well equipped for the steepest ramps. The production from hardened tool steel ensures low wear and thus a very long durability. The cassette is compatible with all conventional Shimano / SRAM MTB freewheel bodies.
The chain places particularly high demands on e-bikes. After all, it not only has to be able to transmit very high torque, but also has to be able to switch cleanly at a constantly high output. Thanks to the 1x8 drive of the EX1 group, the EX1 chain has significantly less skewing than other switching groups. Therefore, SRAM was able to construct a wider and more stable chain. In combination with the EX1 cassette, it offers very smooth running even when changing gears and can transmit significantly higher forces than conventional chains.
The lightweight EX1 crank arms have been specially designed for the middle engines from Bosch and Brose. Their stiff and robust construction is also suitable for use in rough terrain. The cranks with 170 mm or 175 mm crank length.
NOTE: The crank is only suitable for e-bikes with mid-motors with ISIS crank mount!
The SRAM EX chainrings have been specially developed for the Bosch e-bike mid-mounted motors. In order to be able to transmit the high torque of the engine without chain drops, the teeth are equipped with the proven X-Sync tooth profile. The alternating narrow and wide teeth fit perfectly into the chain with this profile and hold it on the chainring even in rough terrain. Special cutouts on the base of the teeth counteract silting up of the chain and chainring in adverse conditions. The chainrings are made of steel for durability and to be able to withstand the strength of Bosch motors. They are available with 14, 16 or 18 teeth.
Rear derailleur - 285g
Trigger shifter - 122g
Cassette - 360g
Chain - 345g
Crank - 500g
Total weight - from 1662g