Abstract: An adjustable rear wheel dropout system includes an over center clamp, toggle clamp or four bar link mechanism to tension a bicycle's chain or belt drive system. A toggle clamp system moves the rear axle as needed to achieve the desired tension in the chain or belt. The over center toggle clamp system is also useful in facilitating the repeatable reinstallation of a rear wheel in a predetermined position. A wheel skewer system secures or locks the adjustable rear wheel dropout in the desired location. The dropout system includes a chain stay adjustment area or void to allow the wheel skewer to be inserted though the dropout. After the end position is secured by the toggle system, the wheel skewer further secures the dropout position as the wheel skewer is tightened to secure the wheel to the bicycle.

Abstract: An adjustable rear wheel dropout system includes an over center clamp, toggle clamp or four bar link mechanism to tension a bicycle's chain or belt drive system. A toggle clamp system moves the rear axle as needed to achieve the desired tension in the chain or belt. The over center toggle clamp system is also useful in facilitating the repeatable reinstallation of a rear wheel in a predetermined position. A wheel skewer system secures or locks the adjustable rear wheel dropout in the desired location. The dropout system includes a chain stay adjustment area or void to allow the wheel skewer to be inserted though the dropout. After the end position is secured by the toggle system, the wheel skewer further secures the dropout position as the wheel skewer is tightened to secure the wheel to the bicycle.