Mountain bikers with an affinity for technology will still remember the Hammerschmidt gear crank, but the gear crankset failed to achieve a real breakthrough. Now the start-up company Efneo is taking a new approach: The Polish crank with planetary gearing corresponds to the gear ratio of a chainring set with 28/40/50 teeth, offers a gear range of 179 percent and is activated using a thumb shifter. The compatibility is remarkable:

Easy assembly - assuming BSA square bottom bracket
The Efneo crank is easy to install on a bike with a 68mm BSA square bottom bracket. However, on modern mountain bikes with external bearing shells and numerous press-fit standards, the square bottom bracket era has been over for at least 10 years. If you want to screw the gear crank onto your bike, you will still have to find a solution using bottom bracket adapters. The manufacturer recommends the crank for moderate off-road use and holds out the prospect that other axle standards may be used.

Crowdfunding as a start-up aid
Efneo secured the financial start-up aid on the indiegogo platform. The first cranks will then go to supporters on this platform this fall.