Drop-out mounting structure of bicycle frame

A drop-out mounting structure for mounting a drop-out member as a wheel mounting unit to a drop-out mounting unit of a bicycle frame with a bolt, the drop-out mounting structure comprising:

• an assembly slot formed at the drop-out mounting unit to insert the drop-out member inside the drop-out mounting unit;
• and
• a stopper unit formed at an upper end part of the drop-out member with a length that is longer than an opening end of the assembly slot,
• wherein:
• the assembly slot is formed at a lower end of the drop-out mounting unit in a front and rear direction;
• the stopper unit is formed at the upper end part of the drop-out member in the front and rear direction;
• and
• the drop-out member is inserted inside the drop-out mounting unit through the assembly slot by turning the drop-out member in a direction, supports an inner upper end of the drop-out mounting unit through the stopper unit, and is fastened to the drop-out mounting unit by the bolt in a fixedly disposed state, and
• wherein the stopper unit includes:
• a first stopper protrusion formed to be protruded from the upper end part of the drop-out member to a rear side;
• and
• a second stopper protrusion formed to be protruded from the upper end part of the drop-out member to a front side with a protrusion length that is larger than the first stopper protrusion.