Bosch eShift with TRP E.A.S.I. A12: Bosch and TRP bring automatic shifting to e-bikes

That alone would be a big news story: The Taiwanese component giant TRP is launching an electronic shifting system with wireless communication between the shifter and rear derailleur. But that's not all. The E.A.S.I. A12 was developed in collaboration with Bosch and, with the Bosch Performance SX motors and Performance CX fully automatic gear shifting in future. The two manufacturers are thus cooperating once again, following on from the joint ABS brake. The hardware comes from Tektro's premium brand TRP, the software and the matching e-drive from Bosch. A new chapter in Bosch's eShift history, which has not yet made it onto sporty e-mountainbikes.

What can the automatic gearstick from Bosch and TRP do?

The Bosch-TRP combo is Shimano XT DI2 with Autoshift and Srams Eagle Powertrain the third system that brings fully automatic gear changes with derailleur gears for E-MTB and E-Gravel to the starting line. The basic functions of the three systems are very similar. They enable automatic shifting and gear changes while rolling.

The Bosch smart system can access various data such as the current speed, cadence, power and torque as well as the gear engaged. On this basis, an algorithm calculates the appropriate gear to provide the rider with the desired cadence at all times. This cadence can be adjusted to individual preferences via the app or directly on the display.

Automatic shifting - ingenious feature or technology overkill? Three EMTB readers were allowed to test the Sram and Shimano systems in detail. You can read their verdict here in the detailed article!

It is also possible to shift gears while rolling, without turning the cranks, as the motor drives the chainring for the shifting process. Bosch calls this "Rollshift". The rider can override the gears manually at any time or switch completely to manual mode by pressing a button on the TRP shifter. The selected shift mode is shown in the display, as is the gear engaged. This applies to the Bosch Kiox and Purion displays, as well as the ridescreen on the smartphone.

Another feature: To protect the components, Bosch's eShift reduces the torque of the motor for a fraction of a second during the shifting process. This should significantly reduce wear on the chain and cassette and prevent defects. It should also make shifting particularly smooth.

The facts about Bosch's automatic shifting system with TRP E.A.S.I.

• Works with Bosch Performance CX and Bosch Performance SX in the Smartsystem
• Hardware: Wireless radio control TRP E.A.S.I. A12, 12-speed
• Power supply of the rear derailleur via the main battery of the e-bike
• Fully automatic gear changes
• Rollshift: gear change possible while rolling
• Smooth gear changes thanks to torque reduction
• Switch between manual and auto mode at the touch of a button
• Can be retrofitted to Smart System Bikes
• Available from the beginning of 2025

TRP E.A.S.I. A12: The hardware

The TRP drivetrain will only be available in combination with Bosch e-bikes, but TRP promises that the drivetrain will also be available for retrofitting in the aftermarket. The rear derailleur and shifter have been completely redeveloped for the E.A.S.I. - explicitly for combined use. While communication between the lever and rear derailleur is wireless, the rear derailleur receives its power by cable from the Bosch battery in the e-bike. The new gear system is designed for twelve gears.

There are two suitable 12-speed cassettes from TRP. The high-quality EVO 12, which we already know from the mechanical TRP Evo 12 shifting systemis lightweight and relies on two large aluminium sprockets and a wide range of 10 to 52 teeth. New is the cheaper and more durable steel cassette with 11 to 50 teeth, in which the first two sprockets can be replaced separately. In principle, however, the derailleur also works with Shimano wear parts.

CEO Claus Fleischer in an interview on automatic switching

EMTB Magazine: Will the automatic shifting system from Bosch and TRP also convince demanding riders in difficult terrain?

Claus Fleischer, CEO Bosch E-Bike Systems: The automatic transmission offers numerous advantages on easy terrain. Think less about shifting gears, have more fun driving! If the terrain becomes more demanding, you can change gear manually at any time at the touch of a button. As you are more anticipatory than the sensors, the fully manual setting is recommended on extreme uphills.

Is an automatic gearstick with a Bosch motor also conceivable with gears from Shimano and Sram?

This first solution for E-MTB derailleur systems was developed in cooperation with Tektro, but the necessary interfaces and the automatic algorithm are provided by the smart system. In this respect, solutions with other derailleur providers are also conceivable.

Will all E-MTBs soon have an automatic gearshift?

eShift offers added comfort and riding enjoyment - on an e-MTB as well as in the city. In this respect, we will probably see more automatic gearshifts in the future, with increasingly intelligent algorithms and manual selection options. However, purely manual gear changes will continue to exist.