Provided is a power generation system. The power generation system comprises: a pneumatic tire; a wheel on which the pneumatic tire is mounted; and at least one generator wind turbine attached to the pneumatic tire and/or the wheel in a cavity defined by the pneumatic tire and the wheel. The generator wind turbine is configured to lay flat or stand upright.

Provided is a power generation system. The power generation system comprises: a pneumatic tire; a wheel on which the pneumatic tire is mounted; and at least one generator wind turbine attached to the pneumatic tire and/or the wheel in a cavity defined by the pneumatic tire and the wheel. The generator wind turbine is configured to lay flat or stand upright.

A method of manufacturing a rim includes placing at least one braided sleeve on a core dimensioned to define a shape of an internal wall of the rim. The method includes inserting the braided sleeves placed on the core, inside a mold that is dimensioned to define a shape of an external wall shape of the rim. The method further includes injecting a resin inside the mold to contact the mold and impregnate the sleeves and other layers with resin. The method also includes curing the resin to form the internal and external walls of the rim and obtain a cured rim having the core connected thereto. The method further includes removing the cured rim and core from the mold and melting the core to get it out of the rim.

A tire information acquisition device includes: a sensor unit including a sensor configured to acquire tire information; a sensor holder formed in a cylindrical shape holding the sensor unit, and composed of a non-metallic material having flexibility and air permeability; and a band having a band circumferential length adjustable by a fastening portion provided at one end and configured to reversibly fasten an other end, and the band is fastened to a rim in a state where the band is inserted into the sensor holder.

A hollow structure has a hollow body with an annular first space and at least one resonator. In the resonator there is formed an elongated second space with a pair of openings at two ends thereof. Each of the pair of openings opens inwardly toward the interior of the first space. The ratio of the length of a centerline of the second space to the length of a centerline of the first space is within a range of from 0.45 to 0.55. The second space is disposed in a curve along a circumferential surface of the first space and is shaped such that one of the two ends of the second space is folded back toward the other end.

A hollow structure has a hollow body with an annular first space and at least one resonator. In the resonator there is formed an elongated second space with a pair of openings at two ends thereof. Each of the pair of openings opens inwardly toward the interior of the first space. The ratio of the length of a centerline of the second space to the length of a centerline of the first space is within a range of from 0.45 to 0.55. The second space is disposed in a curve along a circumferential surface of the first space and is shaped such that one of the two ends of the second space is folded back toward the other end.

A pneumatic tyre comprising an inner surface of the tyre, wherein a sound absorbing device component is connected to the inner surface of the tyre. The sound absorbing device component comprises a panel with a plurality of perforations and two sidewall sections, the sidewall sections being distinct from the panel, wherein the sidewall sections are connected to the inner surface of the tyre and arranged opposite of each other and wherein the panel is borne by the sidewall sections, thereby positioning the panel at a distance from the inner surface of the tyre and defining an inner volume enclosed by the panel, the sidewall sections and the inner surface. Furthermore, 95 area-% of all perforations which permit access to the inner volume are located on the panel.

A pneumatic tyre comprising an inner surface of the tyre, wherein a sound absorbing device component is connected to the inner surface of the tyre. The sound absorbing device component comprises a panel with a plurality of perforations and two sidewall sections, the sidewall sections being distinct from the panel, wherein the sidewall sections are connected to the inner surface of the tyre and arranged opposite of each other and wherein the panel is borne by the sidewall sections, thereby positioning the panel at a distance from the inner surface of the tyre and defining an inner volume enclosed by the panel, the sidewall sections and the inner surface. Furthermore, 95 area-% of all perforations which permit access to the inner volume are located on the panel.

A bicycle wheel comprises a rim and a valve assembly. The rim includes a radially inner wall having an inner opening and a radially outer wall having an outer opening. A first portion of the rim includes a first securing feature (e.g., inner threads). The valve assembly is positioned in the inner opening and outer opening and includes a second securing feature (e.g., outer threads) engaging the first securing feature. The rim can include a plate that defines the first engaging feature. The valve assembly preferably includes a valve stem and a resilient bumper coupled to the valve stem and aligned with a second portion of the rim. The valve assembly can further include a seal member compressed between the valve stem and the rim. Preferably, the seal member is positioned in an annular groove in an underside of an enlarged head of the valve stem.

A bicycle wheel comprises a rim and a valve assembly. The rim includes a radially inner wall having an inner opening and a radially outer wall having an outer opening. A first portion of the rim includes a first securing feature (e.g., inner threads). The valve assembly is positioned in the inner opening and outer opening and includes a second securing feature (e.g., outer threads) engaging the first securing feature. The rim can include a plate that defines the first engaging feature. The valve assembly preferably includes a valve stem and a resilient bumper coupled to the valve stem and aligned with a second portion of the rim. The valve assembly can further include a seal member compressed between the valve stem and the rim. Preferably, the seal member is positioned in an annular groove in an underside of an enlarged head of the valve stem.