A header of an agricultural harvester comprising: a frame; a first reel assembly connected to the frame, the first reel assembly including: a central rotatable shaft having a longitudinal axis; a plurality of tine bars (206A-F) extending widthwise across the first reel assembly and connected to the central rotatable shaft for rotation therewith; a rotatable coupler (300, 300', 300", 300"') having a rotational axis aligned with the longitudinal axis of the central rotatable shaft; and a first linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the first reel assembly, characterized by: a reel arm connected to the frame and supporting the first reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is connected to the reel arm, wherein the header further comprises a second reel assembly connected to the frame, the second reel assembly including: a central rotatable shaft; a plurality of tine bars (206A-F) extending widthwise across the second reel assembly and connected to the central rotatable shaft for rotation therewith; and a second linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the second reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is supported by the reel arm, and connected to at least one of the central rotatable shafts (204A, 204B) of the first and second reel assemblies (200, 202). a frame; a first reel assembly connected to the frame, the first reel assembly including: a central rotatable shaft having a longitudinal axis; a plurality of tine bars (206A-F) extending widthwise across the first reel assembly and connected to the central rotatable shaft for rotation therewith; a rotatable coupler (300, 300', 300", 300"') having a rotational axis aligned with the longitudinal axis of the central rotatable shaft; and a first linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the first reel assembly, characterized by: a reel arm connected to the frame and supporting the first reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is connected to the reel arm, wherein the header further comprises a second reel assembly connected to the frame, the second reel assembly including: a central rotatable shaft; a plurality of tine bars (206A-F) extending widthwise across the second reel assembly and connected to the central rotatable shaft for rotation therewith; and a second linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the second reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is supported by the reel arm, and connected to at least one of the central rotatable shafts (204A, 204B) of the first and second reel assemblies (200, 202). a central rotatable shaft having a longitudinal axis; a plurality of tine bars (206A-F) extending widthwise across the first reel assembly and connected to the central rotatable shaft for rotation therewith; a rotatable coupler (300, 300', 300", 300"') having a rotational axis aligned with the longitudinal axis of the central rotatable shaft; and a first linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the first reel assembly, characterized by: a reel arm connected to the frame and supporting the first reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is connected to the reel arm, wherein the header further comprises a second reel assembly connected to the frame, the second reel assembly including: a central rotatable shaft; a plurality of tine bars (206A-F) extending widthwise across the second reel assembly and connected to the central rotatable shaft for rotation therewith; and a second linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the second reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is supported by the reel arm, and connected to at least one of the central rotatable shafts (204A, 204B) of the first and second reel assemblies (200, 202). a reel arm connected to the frame and supporting the first reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is connected to the reel arm, wherein the header further comprises a second reel assembly connected to the frame, the second reel assembly including: a central rotatable shaft; a plurality of tine bars (206A-F) extending widthwise across the second reel assembly and connected to the central rotatable shaft for rotation therewith; and a second linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the second reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is supported by the reel arm, and connected to at least one of the central rotatable shafts (204A, 204B) of the first and second reel assemblies (200, 202). a central rotatable shaft; a plurality of tine bars (206A-F) extending widthwise across the second reel assembly and connected to the central rotatable shaft for rotation therewith; and a second linkage assembly connecting the rotatable coupler (300, 300', 300", 300"') to one of the plurality of tine bars (206A-F) of the second reel assembly, wherein the rotatable coupler (300, 300', 300", 300"') is supported by the reel arm, and connected to at least one of the central rotatable shafts (204A, 204B) of the first and second reel assemblies (200, 202).