A scooter fork holds the front wheel onto the scooter and allows the scooter to be steered by rotating in the front of the deck, it does this with the help of a headset. Headsets are made up by two layers of bearings both of which sit in the centre of the fork, at the top and bottom of the head-tube of the deck. It is essential that your forks are securely bolted into the frame via the headset, if they aren't this could cause extensive damage to your scooter components and make the scooter dangerous to ride.
Scooter forks are made using a variety of methods. They can be welded together in production from many pieces, machined from one large piece of metal or forged from molten metal. Or even from a combination of the above methods. Forks are made up of two main pieces. Firstly the legs of the fork which hold the front wheel in place, and secondly the steerer tube which slots through the headset and into the head-tube of the scooter deck.
There are two types of scooter forks available on the market today; Threaded and Threadless. These names refer to the manner in which they are secured in the headset and also how compression is added to the headset to keep the bearings running smoothly.
Both of these styles of forks are very easy to identify. Threaded forks have a large threaded section cut into the fork steerer tube at the top of the fork. This is included to screw the large top nuts of a threaded headset onto. This then adds compression to the headset and keeps the bearings securely held in place.
The second type of fork is the Threadless fork. Threadless forks don't have a thread cut into the top of the steerer and are smooth in appearance. Threadless forks are only compatible with Threadless headsets which add compression via a star nut and bolt. This pulls the Handlebars or Compression Clamp down onto the top of the headset holding everything in place. The large majority of forks used in complete scooters are Threaded, but the more expensive the scooter the more likely they are to have the stronger Threadless system fitted. Here at Route One, we recommend that if possible, riders use the Threadless system as it provides a much stronger setup.
Here is a chart to show which scooters use the Threaded and Threadless systems.