With the introduction of the ST2-Belt in the fall of 2020, this was not only the first Stromer with a belt drive, it was also the first and to date the last Stromer with an integrated gearbox in the motor. It was replaced by the ST2 Pinion in 2023. The 'TDMC CYRO Drive IG' with 750 W and 40 Nm is used. IG stands for Internal Gear.

The gearbox comes from Sturmey Archer, has 5 gears and is shifted with a classic cable pull.
