Multi-speed bicycle transmission

A multi-speed transmission for bicycles, comprising:

• (a) a housing including spaced, opposing face plates, each face plate having a pedal shaft opening and a secondary shaft opening;
• (b) a pedal shaft rotatably disposed within said pedal shaft openings;
• (c) a secondary shaft disposed within said secondary shaft openings, wherein the secondary shaft is spaced from the pedal shaft and substantially parallel thereto;
• (d) a pedal shaft set of gears mounted on the pedal shaft between the face plates, comprising:
• (1) a first set of pedal shaft gears mounted on the pedal shaft, (2) a second set of pedal shaft gears rotatably mounted on the pedal shaft, and (3) a third set of pedal shaft gears rotatably mounted on the pedal shaft and including first means for selective driving engagement with the second set of pedal shaft gears, the third set of pedal shaft gears including a drive gear means for engaging and driving;
• (e) a secondary shaft set of gears mounted on the secondary shaft between the face plates, comprising:
• (1) a first set of secondary shaft gears mounted on the secondary shaft, and (2) a second set of secondary shaft gears rotatably mounted on the secondary shaft and including second means for selective driving engagement with the first set of secondary shaft gears;
• (f) a set of primary pinion gears rotatably attached to means for selectively engaging each pinion gear between the first set of pedal shaft gears and the first set of secondary shaft gears, wherein said means for selectively engaging the primary pinion gears comprises a set of arms each corresponding to said one of primary pinion gears, said each arm having a proximal end pivotally attached to the housing, and a distal end to which said corresponding primary pinion gear is rotatably attached, said arm having a first pivot position where said primary pinion gear is engaged, and a second pivot position where said primary pinion gear is disengaged;
• and
• (g) a permanent pinion gear engaged between the second set of pedal shaft gears and the second set of secondary shaft gears;
• wherein, when one of the primary pinion gears is engaged between the first set of pedal shaft gears and the first set of secondary shaft gears, applying rotary torque to the pedal shaft causes:
• (1) the first set of pedal shaft gears to rotate the first set of secondary shaft gears via the engaged primary pinion gear, (2) the first set of secondary shaft gears rotate the second set of secondary shaft gears, (3) the second set of secondary shaft gears rotate the second set of pedal shaft gears via the permanent pinion gear, and (4) the second set of pedal shaft gears rotate the third set of pedal shaft gears thereby rotating said drive gear means.