Headsets Threaded

Bike Parts - threaded headsets are used on most lowrider and cruiser bicycles.  Threaded means that the headset's hardware threads onto a bicycle fork's steering tube.

21.1mm   or 22.2mm threaded headset are most commonly used with springer forks.

21.1mm and 22.2mm threaded headsets both have all the same size hardware except the top cap aperture is 21.1mm or 22.2mm

21.1mm and 22.2mm size refers to the outer diameter of a fork's steering tube - Springer Fork video      (BMX) Rigid Fork video