Abstract: A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

Abstract: A sprocket guard assembly comprising a sprocket having sprocket radial spokes, and having teeth on an outer perimeter, the teeth disposed in a plane CL1, each sprocket radial spoke communicating with a first cylindrical surface, a circular member having circular member radial spokes, and each circular member radial spoke communicating with a second cylindrical surface, a collar having an outer cylindrical surface, a fastener engaging the collar, the first cylindrical surface and the second cylindrical surface engaging the outer cylindrical surface, all coplanar in a plane CL2, and plane CL1 is offset from plane CL2.

Abstract: A sprocket guard comprising a sprocket having sprocket radial spokes, and having teeth on an outer perimeter, the teeth disposed in a plane CL1, each sprocket radial spoke communicating with a first cylindrical surface, a circular member having circular member radial spokes, and each circular member radial spoke communicating with a second cylindrical surface, a collar having an outer cylindrical surface, a fastener engaging the collar, the first cylindrical surface and the second cylindrical surface engaging the outer cylindrical surface, all coplanar in a plane CL2, and plane CL1 is offset from plane CL2.

Abstract: A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

Abstract: A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

Abstract: A crank arm comprising a crank arm receiving portion, a sprocket, a sprocket guard comprising a sprocket guard receiving portion, a nut engagable with a bolt fixing the sprocket to the crank arm receiving portion, and a third fastener engaging the sprocket guard receiving portion through the bolt.

Abstract: A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

Abstract: A toothed sprocket hub with elastic centering element comprising an input shaft having a receiving portion and a cylindrical outer surface, a sprocket engagable with the input shaft, the sprocket comprising at least two first surfaces each disposed on a bending beam such that each first surface is elastically moveable in a radial direction, the two first surfaces bearing upon the outer surface, the two first surfaces each having a radius d that is less than a radius D of the outer surface, at least one second surface that is radially moveable to a lesser extent than a first surface, the second surface engaging the receiving portion to prevent a relative rotation of the sprocket with the input shaft, and a third surface in cooperative relation to the second surface, the third surface bearing upon the outer surface of the input shaft, the third surface having a clearance fit with the outer surface.

Abstract: A toothed sprocket hub with elastic centering element comprising an input shaft having a receiving portion and a cylindrical outer surface, a sprocket engagable with the input shaft, the sprocket comprising at least two first surfaces each disposed on a bending beam such that each first surface is elastically moveable in a radial direction, the two first surfaces bearing upon the outer surface, the two first surfaces each having a radius d that is less than a radius D of the outer surface, at least one second surface that is radially moveable to a lesser extent than a first surface, the second surface engaging the receiving portion to prevent a relative rotation of the sprocket with the input shaft, and a third surface in cooperative relation to the second surface, the third surface bearing upon the outer surface of the input shaft, the third surface having a clearance fit with the outer surface.