Complex sentence: Most bicycles used this system of freewheels and threaded hubs until the late 1980s, and many new single-speed, especially BMX, bicycles and lower-end multi-geared bicycles continue to be manufactured and sold with freewheels.
Split into simpler sentences: Most bicycles used this system of freewheels and threaded hubs until the late 1980s,. Lower-end derailleured bicycles continue to be manufactured and sold with freewheels.