A detachable chainring assembly includes a first chainring, a second chainring and a locking part. The first chainring includes a first through hole. The second chainring includes a first surface, a second surface, a driven hole, and a plurality of first protrusion parts. The second surface is opposite to the first surface. The driven hole runs through the first surface and the second surface for securing a driving portion of a crank arm. The first protrusion parts protrude from the second surface and are disposed around the driven hole, and at least one of the first protrusion parts has a first locked hole. The locking part is detachably secured to the first through hole and the first locked hole such that the first chainring and the second chainring are jointly secured to each other via the locking part.

Disclosed is a rotation transmission mechanism including: an internal rotation member inserted by a crankshaft of a bicycle; and an external rotation member configured on the internal rotation member. The internal rotation member includes: an internal rotation member body. The external rotation member includes: a circular ring part configured at an outer side of the outer circumferential convex parts; and inner circumferential convex parts protruding to an inner circumferential side of the circular ring part and configured alternately with the outer circumferential convex parts. Elastic deformation parts are configured between the outer circumferential convex parts and the inner circumferential convex parts on a rotation direction side of the advancing outer circumferential convex parts. The outer circumferential convex parts are formed in such a manner that a surface on the rotation direction side is greater than a surface on an opposite side of the rotation direction.

A bicycle chain ring for engaging a chain link of a bicycle chain, the bicycle chain ring including an inner edge fully circumscribing both an opening and an axis of rotation, an inner surface extending between the inner edge and an outer edge where a plurality of chain ring teeth emanate, and a plurality of ramps disposed about the inner surface, wherein at least one of the plurality of ramps includes a lifting surface for initiating lift of a bicycle chain without assistance from the plurality of chain ring teeth. The lifting surface extends radially along the inner surface toward the outer edge, and the at least one ramp has a first end proximate the inner edge and a second end proximate the outer edge. The second end of the at least one lifting surface terminates before reaching the bottom of a trough positioned between two or more of the plurality of chain ring teeth.

A bicycle chainring includes a plurality of teeth extending from a periphery of the chainring wherein roots of the plurality of teeth are disposed adjacent the periphery of the chainring. The plurality of teeth include a first group of teeth and a second group of teeth, each of the first group of teeth wider than each of the second group of teeth. At least some of the second group of teeth are arranged alternatingly and adjacently between the first group of teeth, and wherein the periphery of the chainring is generally non-circular.

A drive system comprising a drive shaft (21) and a chainring (1), wherein the drive shaft (21) has a splined interface (22) for attaching the chainring (1) in a rotationally fixed manner. The drive system has an annular adapter (2) having a radially inner surface with an interface (20) engaging the splined interface (22) of the drive shaft (21) and a radially outer region with at least one first connecting element, wherein the chainring (1) has at least one second connecting element configured to engage the first connecting element, wherein the drive system comprises a first annular adapter (2) with a first axial extension defining a first axial distance between the interface (20) and the first connecting element and a second annular adapter with a second axial extension defining a second axial distance between the interface (20) and the first connecting element.

A pedal-assisted bicycle includes a suspension system of the rear wheel in relation to the frame which allows a predetermined relative displacement between them. The crankset includes: a freewheel device operatively interposed between the drive and muscle shafts; a compensating device operatively interposed between the drive shaft and the gear wheel, The compensating device generates between the two an angular forward compensation stroke between a rest position, and a compensation position, where the forward compensation stroke is limited to a predetermined angle and is opposite to the free stroke of the freewheel device.

A bicycle front shifting system includes operable to transmit a wireless signal, a crank assembly with two crank arms and a pedal on each of the two crank arms. The crank assembly is rotatable about a rotation axis. A front shift unit is coupled to the crank assembly and is rotatable about the rotation axis. The front shift unit includes a chain ring component with a big chain ring and a small chain ring. The small chain ring has a small diameter and the big chain ring has a big diameter that is larger than the small diameter. A shift mechanism is coupled to and rotatable with the chain ring component about the rotation axis. The shift mechanism is configured to receive the wireless signal from the shifter and to shift a chain between the big chain ring and the small chain ring according to the wireless signal.

A method, data processing system and computer program product for customizing a presentation. A set of individual preferences for each individual of a plurality of individuals to form a set of audience preferences is determined, wherein each preference in the set of individual preferences is associated with one of a plurality of versions of the presentation. A set of versions of the presentation from the plurality of versions of the presentation is selected based on the set of audience preferences. The set of versions of the presentation selected from the plurality of versions of the presentation is presented.

A bicycle chainring for engagement with a drive chain includes a plurality of teeth extending from a periphery of the chainring wherein roots of the plurality of teeth are disposed adjacent the periphery of the chainring. The plurality of teeth include a first group of teeth and a second group of teeth.

A bicycle chainring for engagement with a drive chain includes a plurality of teeth extending from a periphery of the chainring wherein roots of the plurality of teeth are disposed adjacent the periphery of the chainring. The plurality of teeth include a first group of teeth and a second group of teeth, each of the first group of teeth wider than each of the second group of teeth. At least some of the second group of teeth are arranged alternatingly and adjacently between the first group of teeth, and at least some of the first group of teeth are asymmetrically wider than each of the second group of teeth.