Abstract: A bicycle frame having a replaceable flexible down tube assembly, wherein the down tube assembly includes a resilient arcuate down tube member with connectors in the form of releasable mounting clips removably attached to the ends of down tube member. The clips clamp on transverse mounting pins in stems attached to the bicycle frame at the ends of the down tube assembly. The clips are releasable to remove the down tube assembly from the frame for replacement or substitution of a down tube having different performance or appearance characteristics. The clips are removable from the down tube for separate replacement of clips and the down tube.

Abstract: A bicycle frame having a replaceable flexible down tube assembly, wherein the down tube assembly includes a resilient arcuate down tube member with connectors in the form of releasable mounting clips removably attached to the ends of down tube member. The clips clamp on transverse mounting pins in stems attached to the bicycle frame at the ends of the down tube assembly. The clips are releasable to remove the down tube assembly from the frame for replacement or substitution of a down tube having different performance or appearance characteristics. The clips are removable from the down tube for separate replacement of clips and the down tube.

Abstract: In accordance with the present invention, an improved bicycle frame according to one embodiment of this invention has a top tube that allows the wheel base to lengthen by resiliently flexing or pivotally deflecting vertically while resisting torsional flex This feature is combined with a resilient, flexible, arcuate down tube extending between the bottom bracket of the bicycle and the bicycle head tube or the intermediate connection points The down tube has at least one arc and springs back to its original position from forces of tension as well as compression The combination of the two flexing members gives the bicycle a smoother ride and may also enhance the delivery of pedal” power to the rear wheel The down tube is replaceable in order to modify the flex characteristics of the frame and physical characteristics, such as head tube and seat tube angle, wheel base, and bottom bracket height.