3 drives in one transmission principle

With an intelligent design, Florian Schlumpf has succeeded in realizing
3 different transmission ratios of the same planetary gearbox and thus being able to use a large proportion
of the required gearbox components for all three gearbox variants.

In addition, the design offers extensive customization options for the respective installation situation.

The narrow planetary gear (10 mm) supplements the chainring with an overdrive or underdrive, depending on the model.

This ideal, inconspicuous addition can be used universally and offers more riding comfort and fun.

A technical innovation without cables, safe and, above all, low-maintenance.

High Speed Drive

The High Speed Drive enables a gear ratio of 1 : 2.5 and 1 : 1. 

So if you are riding at 15-20 km/h in gear 1:1, you can also pedal at the same cadence at 35-50 km/h in gear 1:2.5. The intended use of the High Speed Drive is therefore for powerful S-pedelecs and even significantly faster e-bikes.

This transmission ratio is realized by driving the planet carrier and driving the sun gear while the ring gear is firmly coupled to the housing.


The Speeddrive enables a ratio of
1 : 1.65 and 1 : 1. The Speeddrive can therefore replace the double sprocket at the front. This is particularly advantageous for folding bikes, as the large chain travel of the double sprocket is often almost impossible to achieve on folding bikes. However, belt drives on electric bikes with front or rear-wheel drive also benefit, as this doubles the available gears.

This transmission ratio is achieved by driving the planet carrier and driving the ring gear, while the sun gear is firmly coupled to the housing.


The Mountaindrive enables a reduction ratio of 2.5 : 1 and 1 : 1.

With the additional reduction stage, higher loads can be transported with significantly less force at a moderate crank frequency. A significantly shorter distance is covered per crank revolution. The area of application is heavy bicycles for climbing mountains (velomobiles) or vehicles such as wheelchairs and handbikes that need to be moved with little effort.

This transmission ratio is realized by driving the sun gear and driving the planet gear, while the ring gear is firmly coupled to the housing.

Gear shifting without cables

A kick with the heel, whether at a standstill or at full speed, shifts gears casually and inconspicuously.

In addition to the classic shift knob on both cranks, we also supply shift bars that make shifting even easier.

Variety of variants

Variable bottom bracket width

Our drives allow great flexibility in terms of width and the resulting Q-factor. Bottom bracket axles are available in lengths of 120, 138, 148 and 170 mm with matching bottom bracket housings in widths of BSA 68 - 72 mm. This means that every Drive can be perfectly adapted to every individual installation situation.

Torque arm

For each drive, one element of the planetary gearbox is fixed to the housing in order to support the torque acting on this element on the housing. There are two options for fixing: As standard, a toothed cone is provided for this purpose, which absorbs the torque on the bottom bracket shell. For this, the bottom bracket shell must have a chamfer on the inside of the right-hand side.

If the bottom bracket shell is to remain without a chamfer, we supply the Mountaindrive with a torque arm with an arm that is attached to the frame as an alternative.

Bolt circle BCD

We offer a bolt circle of 130 mm as standard for mounting the chainring.
Alternatively, a 110 mm bolt circle can be selected.


We offer an extensive range of chainrings and the corresponding Y-pads in order to be able to adapt the transmission ratio ultimately acting on the rear wheel to the respective individual conditions. Steel chainrings are also available to be able to withstand high loads.

Option Cargo

If the Mountaindrive is subject to very high loads, the Cargo option can be selected. In this case, some parts are designed in a reinforced version or in steel instead of aluminum.