Bicycle front fork is divided into spring front fork, oil spring front fork, oil gas front fork. 
1, spring front fork 
With a spring as shock absorber medium. 
2, oil spring front fork 
Oil resistance + spring.  This kind of fork is on the basis of the upper, on the other side of the spring to increase the oil damping.  Oil damping is the use of oil to adjust the speed of spring rebound.  This kind of fork generally has springback adjustment, locking function and stroke adjustment function on the basis of adjusting soft and hard. 
3. Oil-gas front fork 
This is similar to the oil spring fork above, except that air pressure is used instead of the spring as the shock absorber.  To adjust the stiffness by pumping air.  There are usually different pressure values for riders of different weights. 
The front fork part is in the front part of the bicycle structure. Its upper end is connected with the handlebar part, the frame part is matched with the front tube, and the lower end is matched with the front axle part to form the bicycle guidance system. 
By turning the handlebars and front forks, the front wheels change direction, which acts as a guide for the bicycle.  In addition, it can also play a role in controlling the cycling.  The force of the front fork part belongs to the nature of cantilever beam, so the front fork part must have enough strength and other properties.