A freehub of a bicycle comprising: a body fitted and rotating on a rotary shaft ; a receiving sleeve connected with a first end of the body and fitted on the rotary shaft , the receiving sleeve including an accommodation holder , the receiving sleeve also including a fixing element corresponding to a second end of the body ; a ratchet assembly arranged between the body and the receiving sleeve , and the ratchet assembly including multiple chutes defined thereon and corresponding to the body , wherein a central axis of a respective chute is not parallel to a central axis of the rotary shaft ; a toothed ring fitted between the fixing element and the body , and the ratchet assembly further including multiple teeth formed on the toothed ring opposite to the multiple chutes , wherein each respective tooth has an arcuate face ; the ratchet assembly further including multiple engagement elements formed in a column shape, such that the multiple engagement elements abut against the multiple teeth , when the multiple engagement elements engage with the multiple teeth ; wherein the ratchet assembly further includes multiple urging elements , wherein a respective urging element has at least one part that is in contact with a respective engagement element , wherein a respective urging element is configured to urge a respective engagement element to linearly move toward the respective tooth so as to engage with the respective tooth , characterized in that the fixing element is formed in a polygon shape, and the toothed ring has a polygonal orifice defined on a center thereof and fitted with the fixing element . a body fitted and rotating on a rotary shaft ; a receiving sleeve connected with a first end of the body and fitted on the rotary shaft , the receiving sleeve including an accommodation holder , the receiving sleeve also including a fixing element corresponding to a second end of the body ; a ratchet assembly arranged between the body and the receiving sleeve , and the ratchet assembly including multiple chutes defined thereon and corresponding to the body , wherein a central axis of a respective chute is not parallel to a central axis of the rotary shaft ; a toothed ring fitted between the fixing element and the body , and the ratchet assembly further including multiple teeth formed on the toothed ring opposite to the multiple chutes , wherein each respective tooth has an arcuate face ; the ratchet assembly further including multiple engagement elements formed in a column shape, such that the multiple engagement elements abut against the multiple teeth , when the multiple engagement elements engage with the multiple teeth ; wherein the ratchet assembly further includes multiple urging elements , wherein a respective urging element has at least one part that is in contact with a respective engagement element , wherein a respective urging element is configured to urge a respective engagement element to linearly move toward the respective tooth so as to engage with the respective tooth , characterized in that the fixing element is formed in a polygon shape, and the toothed ring has a polygonal orifice defined on a center thereof and fitted with the fixing element . <EOS>