Headset
Headsets on freestyle scooters have no difference to those on BMX bikes. Those scooters take a 1 1/8" sized headset. A threaded headset is used for a threaded fork only. Their main use is for those usually running the stock forks. Threadless headsets are used with a compression system on threadless forks such as SCS (Standard compression system), HIC (Hidden internal compression system, which requires oversized bars, IHC (Integrated Headset Compression or ICS (Inverted compression system). The compression used on threaded forks is a locknut, that can be taken off a stock fork. Threadless headsets are used to accommodate threadless forks, which were created because threads compromise the strength of the fork tube.
Read more about this topic: Freestyle Scootering, Freestyle Scooter Parts