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Brompton Non-Chamfer BB Schlumpf Mountain Drive Gearing System German Made (HM)

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Product Details
Item location: Taiwan
Status: In stock
Payment: Paypal, Credit Card
Ship to:: Worldwide (REGISTERED AIRMAIL)

An Ultra wide range gearing system to maximize your Brommie performance. (No BB shell chamfering required)

Brompton as one of the best folding bike design has always suffered the lack of proper gear range for hilly terrains. BIKEgang has kept searching for the best gearing solution for quite some time. Schlumpf Mountain Drive is always our top choice to widen the gear range. Swiss invented Mountain Drive is now produced by Haberstock-Mobility in Germany, we are very proud to introduce the Brompton solution package.

Schlumpf Mountain drive is a gearing system that makes the chainring spinning at a much lower rate (2.5:1). For instance, 56T chainring with mountain-drive engaged, will work like a much smaller one (23 tooth chainring equivalent).

This Brompton version comes with a torque arm to prevent BB shell preparation.


(Chain driven version / Model MD250)

- Cone ring configuration, incl. gears, crankarms, kickplates, 56T Chainring and chain guard (or 60T chainring without cover) - BCD130 spec.

- With two gears: Direct drive 1:1, Underdrive 2.5:1 / 40% (engaged)

- BB and Axle included for Brompton spec. Contact us for other bike or ebike custom model.

Weight:About 1780 g.

Please compare the total weight of mountain-drive to the total weight of a triple

chainring set including shifter, cable, derailleur. Example: Shimano Altus

(48/38/28 teeth): weight incl. right crankarm: 1255g


  • Planetary gearing system with two switch positions: direct drive 1:1, underdrive 2.5:1
  • Direct shifting via push buttons or "easy-shift" - levers on both ends of the spindle. No cables, no rods.
  • Gear housing : Corrosion resistant, completely encased and protected against dust and spray water.
  • Axle: Rides on (replaceable) cartridge bearings. You can expect a lifetime of more than 20'000 miles for the bearings and much more for the mountain-drive.
  • No chamfering on BB shell required.

!!!Special Note !!!

This MOD is not for casual rider, special tools are needed to perform this modification (BB and crank set removal and installation), unless you are an experienced technician, please consult local bikeshop for help.

We are glad to provide all info and manual to help you go through the processes.

Schlumpf Mountain Drive will ship to the world with EMS express service 1 week delivery typical.

Please Drop us a line for manuals and tutorial or custom back order for other bikes, More info can be found at BIKEgang

About Haberstock Mobility

Haberstock mobility is a premium manufacturer of high quality components for ebikes and all other types of bike. The company was founded in 2010.

Their aim is the development of innovative mobility concepts for an urban lifestyle, sport and good wellbeing/ health. The innovative Schlumpf drive (Swiss invention) just as the advanced belt drive are both produced, further developed and sold by Haberstock Mobility. Through many years of experience ideal solutions have been found for every request.

The company acts on a specialised technological network. With the combination of innovative components and intelligent concepts highly developed manufacturing techniques have been born.

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