Patent ID: 8061729
Filing Date: 2011-11-22
Classification: B62K

Abstract:
1. A bicycle frame comprising: a top tube with a front end and a rear end, a head tube with a top end and a lower end, a down tube with a front end and a rear end, a seat tube with a top end and lower end, a pair of chainstays each with a front end and rear end, and a pair of seatstays each with a front end and rear end, the front end of the top tube connected to the top end of the head tube, the front end of the down tube connected to the lower end of the head tube, the top tube and down tube diverging away from each other and extend rearwardly from the head tube, the rear end of the down tube coupled to the lower end of the seat tube, the rear end of the top tube connected to the top end of the seat tube, the top tube, head tube, down tube and seat tube substantially forming a closed main frame loop, the head tube adapted to be coupled to a pivotable front fork which carries a front wheel and handlebars, the top tube, head tube, down tube, and seat tube each comprises a tubular member extending about their own longitudinal axis, the longitudinal axis of the head tube lying in a flat longitudinal central plane which is parallel to a forward direction of travel of the bicycle frame, each tubular member having by a circumferential wall about their longitudinal axis, each point along the length of each the longitudinal axis having a reference line through each point normal the longitudinal axis and parallel to the central plane, selected of the tubular members being reinforced tubular members, the circumferential wall of the reinforced tubular members having remote portions remote from the reference lines and proximate portions priximate the reference lines the remote portions being reinforced compared to the proximate portions to increase the resistance of the reinforced tubular member to lateral out of plane bending compared to in plane bending in the vertical direction, the down tube being a reinforced tubular member, the pair of chainstays comprising a left chainstay and a right chainstay being on opposite sides of the central plane, the pair of seatstays comprising a left seatstay and a right seatstay being on opposite sides of the central plane, the front end of the right chainstay connected to the main frame loop proximate the junction of the seat tube and the down tube on a right side of the central plane, the front end of the right seatstays connected to the seat tube on a right side of the central plane spaced upwardly from the front ends of the chainstays, the rear end of the right chainstay connected to the rear end of the right seat stay on the right side of the central plane rearward of the seat tube, the front end of the left chainstay connected to the main frame loop proximate the junction of the seat tube and the down tube on a left side of the central plane, the front end of the left seatstays connected to the seat tube on a left side of the central plane spaced upwardly from the front ends of the chainstays, the rear end of the left chainstay connected to the rear end of the left seatstay on the left side of the central plane rearward of the seat tube, the right chainstay, the right seatstay, and the seat tube substantially form a closed right rear frame loop, the left chainstay, the left seatstay, and the seat tube substantially form a closed left rear frame loop, the rear ends of the pair of chainstays adapted to support a rear wheel journalled on an axle extending therebetween normal to the central plane, each chainstay and each seatstay comprise a tubular element extending about their own longitudinal axis, each reinforced tubular element having a circumferential wall about its longitudinal axis, each point along the length of the longitudinal axis having a reference line through each point normal the longitudinal axis and parallel to the central plane, selected of the tubular elements being reinforced tubular elements, the circumferential wall of the reinforced tubular elements having remote portions remote from the reference lines and proximate portions proximate the reference lines the remote portions being reinforced compared to the proximate portions to increase the resistance of the reinforced tubular element to resisting lateral out of plane bending compared to in plane bending in a vertical direction, the chainstays each being a reinforced tubular element, wherein each reinforced tubular element is formed from layers of fiber reinforced composite materials including: a radially inner circumferentially extending layer, a radially outer circumferentially extending layer, and a reinforcing layer of fiber reinforced composite material provided over each of the wall portions remote from the lines of symmetry.