Motobecane Fantom Team's TripleActive 4B

3"/4"/5" Adjustable Travel - Four Bar Rocker Arm

I want to explain the difference between the Fantom's 4 bar linkage and the ever so popular Specialized 4 bar design. There may be more to it for all you engineer types out their but the difference is the placement of one very patent protected chain stay pivot. Below is a picture of an Ellsworth which licenses Specializes 4 bar design.

You can see the pivot at the end of the chain stay right above the rear derailleur and before the derailleur hanger.

This picture shows the Fantom's pivot at the bottom of the chain stay right above the hanger. Here is some info on the 4 bar lingage system with a pivot on the seat stay that I put together doing some research.

• A four-bar, seat-stay pivot suspension is similar looking, having a pivot above the drop out instead of in front of the drop out (ie no Horst Link and no patent problem). Having the pivot in front of the drop out (i.e. on the chain stay) allows the linkage components to affect the path of the rear axle, thereby allowing for a more complex arc of the axle path. Placing the pivot on the seat stay (above the drop out) effectively makes the rear axle travel path more like that of a single-pivot bike, since the chain stay is the only component that affects the rear axle's arc.
  Seat-stay four-link pivot bikes perform exactly like similarly placed monopivots under acceleration and chain forces, which means they aren't as neutral under acceleration as Horst-link, four-bar bikes, dw-link, or Split Pivot bikes. However, when brakes are mounted on the seat stays, dw-link, Split Pivot and FSR four-link bikes have an advantage while braking over rough ground. One manufacturer well known for their long-time use of the seat-stay pivot four-bar link suspension is Kona, who incorporate the design on their entire line-up, along with other manufacturers such as Infiza and Icon. (http://en.wikipedia.org/wiki/Bicycle_suspension)
  

So basically what this is saying is a 4 bar linkage system with the pivot on the seat stay does not have a smooth rear axle arch as compared to the 4 bar lingage with the pivot on the seat stay. Also the rear suspension will have a tendency to lock up a little while using the rear brake.