A gear (10) for a bicycle transmission (20) is described, having an external contour (11) with teeth (12a, 12b) formed thereon, wherein the external contour (11) is defined by a maximum pitch diameter (.sub.max) and a minimum pitch diameter (.sub.min), does not have any axes of symmetry and is formed exclusively with point symmetry with respect to its centre of symmetry (M). The invention was therefore based on the problem of developing a gear (10) which improves the pedaling feel of a bicycle transmission (20). The problem is solved in that the external contour (11) exhibits a change in its curvature at every point.

A velocipede includes a pedal crank for pedals to allow an operator to power the velocipede, and a transmission hub or component that is coupled to the pedal crank by a first chain or belt. The transmission component is located rearward of the pedal crank in the frame of the velocipede, such as under a seat position, and is further connected to a rear wheel at an output of the transmission component by a second chain or belt. The transmission has an output that is coupled to a rear wheel assembly. In some embodiments the rear wheel assembly can be mounted in a swingarm that pivots about a transverse axis defined by the output of the transmission. In some embodiments the rear wheel assembly can include an electric motor to drive a rear wheel.

A multi-wheel bicycle with a dual universal joint disposed on a bicycle frame, wherein a first end of the universal joint is mounted to the bicycle frame and a second end of the universal joint is mounted on a moveable end of a bicycle steering fork. A front drive chain is couple from the universal joint to a front tire disposed on a free-wheeling front hub, and a second drive chain is coupled from the first end to a drive sprocket. The drive sprocket is further coupled to a free-wheeling hub attached to a front tire. The coupling provides for transfer of rotational power from the drive sprocket to the front and rear tires through the dual universal joint even as the universal is flexed through its range of motion while steering the bicycle.

An exhaust system for a vehicle including a deep snow exhaust outlet defined by a driveline structural member of the vehicle. If the vehicle includes a turbo charger and an exhaust silencer, the turbocharger and the exhaust silencer are coupled together without exhaust piping therebetween.

An exhaust system for a vehicle including a deep snow exhaust outlet defined by a driveline structural member of the vehicle. If the vehicle includes a turbo charger and an exhaust silencer, the turbocharger and the exhaust silencer are coupled together without exhaust piping therebetween.

A two-stroke engine system has a two stroke engine with an exhaust manifold, a tuned pipe coupled to the exhaust manifold, a stinger coupled to the tuned pipe and a turbocharger coupled to the stinger has a turbine portion having a turbine wheel having an inducer area and a turbine exducer area. A wastegate is in communication with the turbocharger. The wastegate comprises a port area greater than about 37% of the turbine exducer area.

A two-stroke engine system has a two stroke engine with an exhaust manifold, a tuned pipe coupled to the exhaust manifold, a stinger coupled to the tuned pipe and a turbocharger coupled to the stinger has a turbine portion having a turbine wheel having an inducer area and a turbine exducer area. A wastegate is in communication with the turbocharger. The wastegate comprises a port area greater than about 37% of the turbine exducer area.

A bicycle comprises a main frame defining a spring mount, a pivot mount, and a reinforcing strut substantially directly connecting the spring mount to the pivot mount. The reinforcing strut is asymmetrically positioned on one side of the central plane. A rear frame is movable relative to the main frame, a pivot link couples the main frame to the rear frame, and a spring assembly couples a portion of the pivot link to the main frame. The pivot link comprises a left link member, a right link member, and a link bridge connecting the left link member to the right link member. Preferably, the link bridge is positioned rearward of a seat tube on the main frame. The rear frame comprises a seatstay bridge connecting a left and right seatstays. The main frame can support a crank assembly having a chainring offset from the central plane on the same side as the reinforcing strut.

An individual chain wheel for a bicycle front crank arrangement for engaging in a drive chain includes a plurality of teeth formed on a circumference of the chain wheel and having a first and a second group of teeth. The teeth of the second group of teeth are arranged in an alternating manner between the teeth of the first group of teeth. Each tooth has a load flank via which force is transmitted between an adjacent roller of the drive chain and the respective tooth. Each tooth of the first group may also have at least one profile with an opening in the vicinity of the flank, in which a portion of an inner link plate of the drive chain, which portion protrudes beyond the roller, engages.

An individual chain wheel for a bicycle front crank arrangement for engaging in a drive chain includes a plurality of teeth formed on a circumference of the chain wheel and having a first and a second group of teeth. The teeth of the second group of teeth are arranged in an alternating manner between the teeth of the first group of teeth. Each tooth has a load flank via which force is transmitted between an adjacent roller of the drive chain and the respective tooth. Each tooth of the first group may also have at least one profile with an opening in the vicinity of the flank, in which a portion of an inner link plate of the drive chain, which portion protrudes beyond the roller, engages.