Wilbers Zero Friction Progressive Fork Springs K75 models with Showa fork 08-'91-On

Wilbers Progressive Fork Springs have several advantages over linear springs. A Progressive Rate Spring has the advantage of a rising rate resistance to compression. The benefit of this is that the spring can be soft enough at the start of the travel to offer a "plush" ride, yet be firm enough at the end of the travel to soak up the big bumps.