Adjustably sized bicycle frame

A bicycle comprising:

• a rear sprocket connected to a driven rear wheel;
• a crankset having a front sprocket and connected to the rear sprocket by a chain or toothed belt;
• wherein at least one of the front or rear sprocket includes a sprocket assembly, the sprocket assembly including an inner sprocket and an outer annular sprocket detachably connectable to the inner sprocket, the sprocket assembly having a first configuration where the outer annular sprocket is detached from the inner sprocket and a second configuration where the outer annular sprocket is connected to the inner sprocket such that the inner sprocket and outer annular sprocket are concentrically nested;
• wherein the inner sprocket has a plurality of teeth which engage with the chain or toothed belt when in the first configuration;
• and
• wherein the outer annular sprocket has a radially outer surface having a plurality of teeth which engage with the chain or toothed belt when in the second configuration and a radially inner surface having a plurality of teeth which engage with the teeth of the inner sprocket when in the second configuration;
• wherein the number of teeth on the radially outer surface of the outer annular sprocket is greater than the number of teeth on the inner sprocket and the sprocket assembly is convertible between the first and second configurations to alter a gear ratio of the bicycle.

A bicycle frame comprising:

• a front portion configured to receive a front wheel assembly;
• a rear portion configured to receive a rear wheel assembly;
• and
• a connecting member connected to the front portion at a first connecting point and connected to the rear portion at a second connecting point, the first and second connecting points being spaced from one another along the length of the connecting member;
• wherein one of the front and rear portions extends towards and is connected to the other of the front and rear portions at a third connecting point to form a link;
• wherein the front and rear portions are movable relative to one another and the link restricts the relative positions of the front and rear portions;
• wherein the relative movement of the front and rear portions includes a translational component;
• wherein the frame is configured so as to allow a distance between at least two of the connecting points to be adjusted;
• wherein adjustment of said distance increases or decreases the size of the frame;
• wherein the connecting member is configured to receive a seat assembly;
• and
• wherein adjustment of said distance increases both a vertical and a horizontal dimension of the frame or decreases both a vertical and a horizontal dimension of the frame.