Abstract: An adjustable bicycle frame for change in the riding modes is provided with a bottom bracket secured to pedals; a seat tube extending upward out of the bottom bracket; a chain stay extending rearward out of the bottom bracket and the seat tube; a rear wheel rotatably secured to the chain stay and contacting the ground; a head tube with a stem pivotably secured thereto; a fork pivotably secured to the head tube and extending downward; a front wheel rotatably secured to the fork stay and contacting the ground; a rearward inclined telescopic tubing including first and second tubes. After changing length of the telescopic tubing, a length between the front wheel and the rear wheel is changed, an inclined angle of the seat tube is changed, and an inclined angle of the head tube is changed coherently, thereby implementing a racing mode or a slow, urban riding mode.

Abstract: An adjustable bicycle frame for change in the riding modes is provided with a bottom bracket secured to pedals; a seat tube extending upward out of the bottom bracket; a chain stay extending rearward out of the bottom bracket and the seat tube; a rear wheel rotatably secured to the chain stay and contacting the ground; a head tube with a stem pivotably secured thereto; a fork pivotably secured to the head tube and extending downward; a front wheel rotatably secured to the fork stay and contacting the ground; a rearward inclined telescopic tubing including first and second tubes. After changing length of the telescopic tubing, a length between the front wheel and the rear wheel is changed, an inclined angle of the seat tube is changed, and an inclined angle of the head tube is changed coherently, thereby implementing a racing mode or a slow, urban riding mode.

Abstract: An adjustable bicycle frame for change in the riding modes is provided with a bottom bracket secured to pedals; a seat tube extending upward out of the bottom bracket; a chain stay extending rearward out of the bottom bracket and the seat tube; a rear wheel rotatably secured to the chain stay and contacting the ground; a head tube with a stem pivotably secured thereto; a fork pivotably secured to the head tube and extending downward; a front wheel rotatably secured to the fork stay and contacting the ground; a rearward inclined telescopic tubing including first and second tubes. After changing length of the telescopic tubing, a length between the front wheel and the rear wheel is changed, an inclined angle of the seat tube is changed, and an inclined angle of the head tube is changed coherently, thereby implementing a racing mode or a slow, urban riding mode.

Abstract: An adjustable bicycle frame for change in the riding modes is provided with a bottom bracket secured to pedals; a seat tube extending upward out of the bottom bracket; a chain stay extending rearward out of the bottom bracket and the seat tube; a rear wheel rotatably secured to the chain stay and contacting the ground; a head tube with a stem pivotably secured thereto; a fork pivotably secured to the head tube and extending downward; a front wheel rotatably secured to the fork stay and contacting the ground; a rearward inclined telescopic tubing including first and second tubes. After changing length of the telescopic tubing, a length between the front wheel and the rear wheel is changed, an inclined angle of the seat tube is changed, and an inclined angle of the head tube is changed coherently, thereby implementing a racing mode or a slow, urban riding mode.

Abstract: A release device mounted in a bicycle includes a fork including a socket at a bent portion and two yoke arms extended downward from both sides of the socket to mount a front wheel at distal ends thereof; a sleeve fastened in the socket with an upper portion thereof projecting from the socket, the sleeve including at least one longitudinal top slit; an abutment tube including an upper extension passing a head tube to be threadedly secured to a stem; and a clamp put on an upper portion of the sleeve. The clamp is adapted to either fasten the sleeve and the abutment tube together by contracting the slit by exerting a force in a first direction or unfasten the sleeve and the abutment tube by exerting a force in a second direction opposing the first direction.

Abstract: A release device mounted in a bicycle includes a fork including a socket at a bent portion and two yoke arms extended downward from both sides of the socket to mount a front wheel at distal ends thereof; a sleeve fastened in the socket with an upper portion thereof projecting from the socket, the sleeve including at least one longitudinal top slit; an abutment tube including an upper extension passing a head tube to be threadedly secured to a stem; and a clamp put on an upper portion of the sleeve. The clamp is adapted to either fasten the sleeve and the abutment tube together by contracting the slit by exerting a force in a first direction or unfasten the sleeve and the abutment tube by exerting a force in a second direction opposing the first direction.

Abstract: A portable bicycle comprises a front bar having a front end coupled to a head tube, a rear frame section including a lower seat tube extended upwardly from a bottom bracket, a upper seat tube spaced and aligned with the lower seat tube, and a hollow rear bar for slidably receiving the front bar, the rear bar being intersected the upper and lower seat tubes, and a fastening mechanism for securing the front bar to the rear bar. Detaching a seat post and a saddle, unfastening the fastening mechanism, fully projecting the front bar from a rear opening of the rear bar, and fastening the fastening mechanism will shorten the distance between front and rear wheels to a minimum and facilitate the bicycle to store or carry in a much reduced size.

Abstract: A stretching bicycle comprises a front frame section having a hollow front bar as a portion of crossbar, a rear frame section having a hollow rear bar for slidably receiving the front bar, the front and rear bars being disposed in a straight line not aligned with the front and rear wheels, and fastening means for securing the front and rear bars together at a front opening and a rear opening of the rear bar respectively. The bicycle has the advantages of adjusting length for accommodating users of different body heights in use, saving storage space after disassembly, and being structurally strong and lightweight.

Abstract: A detachable bicycle comprises a front frame section including a joint tube at a rear end of the crossbar, a rear frame section including a sleeve extended forward, obliquely from the bottom bracket for receiving a lower portion of the down tube, and a seat tube extended upward from the bottom bracket of the joint tube wherein the seat tube is substantially perpendicular with respect to the down tube, and a seat post inserted through the joint tube and into the seat tube. The seat post and the seat tube are secured to the joint tube by two quick releases. The down tube is also secured to the sleeve by a quick release.

Abstract: Provided are parallel crossbars mounted in a stretchable bicycle comprising unitary front and rear connecting devices made of aluminum formed by extrusion, either connecting device comprising two parallel channels each having an open inner side being in communication with the open inner side of the other channel, upper and lower plates formed between the channels, and two openings formed on the upper and lower plates respectively wherein a head tube or seat tube has its upper end fixedly connected to the openings; two sliding tubes adapted to slide through the channels respectively; and a plurality of quick releases each comprising a bolt having a threaded end inserted through the plates, a nut threadedly secured to the bolt, a lever, and a cam shaped pivot. Pivoting the lever downward about the pivot will flexibly compress the plates toward each other for fastening the sliding tubes.

Abstract: A detachable bicycle. The bicycle includes front and rear frame sections and a detachable device having a first assembly device including a lower first sleeve extended upward from a bottom bracket sleeved on a front axle of sprocket wheel. The first sleeve includes a snap member, and an upper second sleeve at a lower end of a seat tube. The second sleeve includes a mating snap member adapted to releasably couple to the snap member. The second assembly device is adjacent to the top of the seat tube. The second assembly device includes a first coupling device formed on the seat tube and a second coupling device formed at a forward end of the seat stay. The first and the second coupling devices are releasably coupled together.

Abstract: A detachable bicycle is disclosed. The bicycle comprises a front frame section including a first crossbar, a rear frame section including a second crossbar having second fastening structure for matingly coupling to first fastening structure of the first crossbar when a rear open end of the first crossbar is inserted into the second crossbar, and a fastening mechanism including two ring fasteners. Each ring fastener is operative to fasten front and rear ends of the second crossbar on the open end of the first crossbar. An adverse effect caused by different forces exerted on the frame sections when a drives propels the bicycle by means of pedals can be substantially eliminated by the invention.

Abstract: A portable bicycle comprises a front bar having a front end coupled to a head tube, a rear frame section including a lower seat tube extended upwardly from a bottom bracket, a upper seat tube spaced and aligned with the lower seat tube, and a hollow rear bar for slidably receiving the front bar, the rear bar being intersected the upper and lower seat tubes, and a fastening mechanism for securing the front bar to the rear bar. Detaching a seat post and a saddle, unfastening the fastening mechanism, fully projecting the front bar from a rear opening of the rear bar, and fastening the fastening mechanism will shorten the distance between front and rear wheels to a minimum and facilitate the bicycle to store or carry in a much reduced size.

Abstract: A stretching bicycle comprises a front frame section having a hollow front bar as a portion of crossbar, a rear frame section having a hollow rear bar for slidably receiving the front bar, the front and rear bars being disposed in a straight line not aligned with the front and rear wheels, and fastening means for securing the front and rear bars together at a front opening and a rear opening of the rear bar respectively. The bicycle has the advantages of adjusting length for accommodating users of different body heights in use, saving storage space after disassembly, and being structurally strong and lightweight.

Abstract: A detachable bicycle is provided. The bicycle comprises front and rear frame sections and detachable means comprising a first assembly device including a lower first sleeve extended upward from a bottom bracket sleeved on a front axle of sprocket wheel, the first sleeve including a snap member, and an upper second sleeve at a lower end of a seat tube, the second sleeve featured a mating snap member adapted to releasably couple to the snap member; and a second assembly device adjacent top of the seat tube, the second assembly device including a first coupling device formed on the seat tube and a second coupling device formed at a forward end of the seat stay, the first and the second coupling devices being releasably coupled together.

Abstract: A detachable bicycle is disclosed. The bicycle comprises a front frame section including a first crossbar, a rear frame section including a second crossbar having second fastening means for matingly coupling to first fastening means of the first crossbar when a rear open end of the first crossbar is inserted into the second crossbar, and a fastening mechanism including two ring fasteners. Each ring fastener is operative to fasten front and rear ends of the second crossbar on the open end of the first crossbar. An adverse effect caused by different forces exerted on the frame sections when a drives propels the bicycle by means of pedals can be substantially eliminated by the invention.

Abstract: A stretchable bicycle comprises a separate but connectable crossbar consisting of a sliding bar extended rearward from a head tube of front frame and a cross tube fixed to a support tube of rear frame, the cross tube being adapted to telescopically receive and permit the sliding bar to project from its rear end. Also, two quick-releases are provided for fastening the sliding bar at both ends of the cross tube respectively. Hence, a distance between two wheels can be adjusted by sliding a desired portion of the sliding bar inside the cross tube.

Abstract: A detachable bicycle is disclosed. The bicycle comprises a front frame section comprising a joint tube at a rear end of the crossbar; a rear frame section comprising a sleeve extended forward, obliquely from the bottom bracket for receiving a lower portion of the down tube, and a seat tube extended upward from the bottom bracket to have its upper portion inserted into the joint tube wherein the seat tube is substantially perpendicular with respect to the down tube; and a seat post inserted through the joint tube into the seat tube. The seat post and the seat tube are secured to the joint tube by means of a first quick release and a second quick release respectively. The down tube is secured to the sleeve by means of a third quick release.

Abstract: A stretchable bicycle comprises a separate but connectable crossbar consisting of a sliding bar extended rearward from a head tube of front frame and a cross tube fixed to a support tube of rear frame, the cross tube being adapted to telescopically receive and permit the sliding bar to project from its rear end. Also, two quick-releases are provided for fastening the sliding bar at both ends of the cross tube respectively. Hence, a distance between two wheels can be adjusted by sliding a desired portion of the sliding bar inside the cross tube.