Schlumpf Speed Drive 165% Planetary Gear Internal Front Gearing w/

The Schlumpf Speed Drive from Haberstock Mobility is an internal planetary gearing system that replaces the crankset and bottom bracket of a bicycle, providing a two-speed internal shifting mechanism. The two settings have a ratio of 1:1 and 1:1.65 respectively, meaning the Speed Drive provides a 165% gearing advantage over your chosen chainring, all with a click of your heel against the button on the cranks! This particular Speed Drive was a take-off from a bike approximately twenty years ago. It is in good working order and has recently been cleaned up. It includes 170mm crank arms, strike plates for the buttons (which make actuating the button on the Speed Drive easier), a 36-tooth chainring, and a chain guard. I don't know if it was new when it was removed, so I have to say it has an unknown number of miles on it. Regardless, it was pretty dirty when I got it from hanging in a garage for more than a decade, and I cleaned it as best I could without chucking it into a parts cleaner and possibly messing up the internals. The strike plates have branding from the now-closed Recumbent Bike Riders (RBR) bike shop in State College, Pennsylvania. One of the strike plates is much lighter in color due to exposure to sunlight. More information about the Schlumpf Speed Drive can be found here: http://www.schlumpfdrive.com/index.php/speed-drive.html Their extremely-useful manual can be found on their website, but here is the direct link. The installation information begins on page 11: http://www.schlumpfdrive.com/index.php/technical-documents.html?file=files/Schlumpf-Dateien%20EN/HandbuchEN-Schlumpf/Manual-Sclumpf-Speed-Drive.pdf The most relevant information is probably, "What bottom bracket shells can this fit in, and what do I need in order to install it?" I'll tell you here: The Speed Drive fits any chamferred BSA bottom bracket shell (inner diameter of 33.6 - 34mm), and fits bottom bracket shell widths of 68-72mm. Special cones are available to space the Speed Drive correctly. A special tool that Schlumpf sells and refers to as a "half-inch socket spanner" can help with installation but, from what I've read, isn't strictly necessary.