Right crank arm assembly for a bicycle and crank arm thereof

Right crank arm assembly for a bicycle, comprising a right crank arm having at least two free end portions spaced away from a rotation axis,

• a first annular element having at least one first coupling portion directly coupled with a respective one of said crank arm free end portions, at least one second annular element coupled with said crank arm and of a smaller size than said first annular element, wherein said first annular element comprises a toothing that extends radially towards the outside along a primitive circumference having a predetermined diameter,
• wherein said at least one first coupling portion is contained in a first area extending radially towards the outside starting from an ideal circumference having a diameter that is less than said predetermined diameter,
• wherein said at least one first coupling portion is defined by at least one first coupling element that is entirely formed on a cantilevered portion of said first annular element and extends radially inward up to said ideal circumference, and said at least one first coupling portion is axially separated from said second annular element,
• wherein said first annular element comprises at least one first contact element with said crank arm which is structurally distinct from said at least one first coupling element, said at least one first contact element extending radially cantilevered from an inner surface of said first annular element and being entirely contained in said first area,
• wherein said crank arm has an inner side intended, in use, to face towards the frame of the bicycle and an outer side opposite said inner side, wherein said at least one first contact element acts on said crank arm on one of said sides,
• wherein said first annular element comprises at least one second contact element that acts on said crank arm on the other of said sides, and
• wherein said at least one second contact element extends cantilevered from said inner surface of said first annular element on the opposite side to said at least one first contact element with respect to said at least one first coupling element.