the"Springer forks"

by frame
The springer fork is an early type of leading link fork. A springer fork does not have the suspension built into the fork tubes, but instead has it mounted externally, where it may be integrated into the triple tree. This style of fork may be found on antique motorcycles or choppers, and is available today on Harley-Davidson's Softail Springer.
While it may have an exposed spring near the triple clamp, a springer fork is distinguishable from a girder fork by its two parallel sets of legs. The rear is firmly fixed to the bottom triple clamp (usually brazed or welded). A short leading link holds the wheel and the forward leg which actuates the springs (usually mounted on the triple clamp).

the"Girder fork"

One of the earliest types of motorcycle front suspension. The girder fork consists of a pair of uprights attached to the triple clamp by linkages with a spring usually between the top and bottom triple clamps. The design reached its peak in the "Girdraulics" used on "The Vincent" motorcycle. Girdraulic forks featured forged alloy blades for extra strength and hydraulic damping.

While it may have an exposed spring near the triple clamp, a girder fork is distinguishable from a springer fork by the wheel being fixed firmly to the (usually a long diamond shape) upright. The pivot points are short links mounted to the top and bottom triple clamps. The spring is (usually) mounted to the girder and compressed against the upper triple clamp.by frame