Compact foldable bicycle frame, has spacer holding case and reinforcing part of cycle subjected to efforts of two chains on two chainrings and two cogs, where one of cogs is placed at exterior of frame

摘要

The frame has a cog (C1) coupled to a chainring (A2) by an axle (D) freely turning in a case, and a pedal assembly connected to a cog (C2) by a chain (B2) mounted on a back wheel. The cog (C1) and the chainring are fixed at each end of the axle and are positioned on both sides of a spacer (E). The cog (C1) is placed at exterior of the frame, and the chainring is placed at interior of a seat stay (F) and a base (G) in extension from the cog (C2). The spacer holds the case and reinforces a part of the cycle subjected to efforts of two chains (B1, B2) on two chainrings (A1, A2) and the cogs.