MOTORCYCLE SUSPENSION:
Hub-center steering (A swingarm in the front)
Hub-center steering is one of several different types of front end suspension/steering mechanisms used in motorcycles. Hub-center steering is characterized by a swingarm that extends from the bottom of the engine/frame to the center of the front wheel instead of two forks. A sort of horizontal forks running to the center of the front wheel, a series of pushrods are used to hold the front wheel in place.
The advantages of using a hub centre steering system instead of a more conventional motorcycle fork are that hub centre steer separates the steering, braking, and suspension functions. With a fork the braking forces are put through the suspension, a situation that leads to the suspension being compressed, using up a large amount of suspension travel which makes dealing with bumps and other road irregularities extremely difficult. Also, having the steering working through the forks also causes problems with stiction, decreasing the effectiveness of the suspension.
Its complicated assembly is only one of the reasons hub-center steering is implemented in relatively few motorcycle models. The telescopic fork steering system is much more commonly used.
Currently, Bimota's Tesi 2D and the Vyrus 984C3 2V and the 985C3 4V are the only production motorcycles using hub-steer.
See pictures. Enjoy!
PHOTOS
Photo courtesy: Googled 'em 
