The invention relates to methods for producing propylene polymers, which are suited for fiber spinning and which are comprised of propylene, ethylene and/or of C4-C18 alk-1-enes, whereby at least 90 mol % of the monomeric units contained in the propylene polymers results from the polymerization of propylene. According to the inventive methods, the corresponding monomers are polymerized by means of a metallocene catalyst system to form propylene polymers with a relationship Q = MW/MN of less than or equal to 2.2, and: Q represents a measure for the extent of the molar mass distribution; MW represents the mean molar mass; MN represents the numerical mean of the molar mass, and; MW and MN are determined by gel permeation chromatography (GPC) at 145 °C in 1,2,4-trichlorobenzene. The inventive methods are characterized in that the propylene polymers are peroxidically or thermally decomposed afterwards. The invention also relates to propylene polymers that can be obtained by using these methods, to a method for producing various propylene polymers of this type, which differ in their melt flow rates, to the use of the propylene polymers for producing fibers, and to films, fibers and shaped bodies made from these propylene polymers.