A bicycle wheel rim structure is provided with a rim, a cap and a tape. The rim includes a first annular side portion, a second annular side portion and an annular bridge portion extending between the first and second annular side portions. The bridge portion has at least one opening. The cap includes a base plate and a projection. The base plate overlies an outer rim surface of the annular bridge portion. The projection extends from the base plate into the at least one opening. The tape is attached to the outer rim surface of the annular bridge portion and overlying the base plate of the cap. The tape is dimensioned to cover an interface between a peripheral edge of the base plate of the cap and the outer rim surface of the annular bridge portion.