You can clearly see that all of the bikes have an initially rearward axle path. This means that the rear wheel will initially move backwards slightly as the suspension compresses. The more rearward the axle path (to a point) the better the suspension will react to small square edge obstacles (for example braking ruts).
(the chainstay lengths are not the same for each bike, this graph just shows the exaggerated axle path from its uncompressed origin)
Rampant :
The slightly rearward axle path adds to the pedal efficiency when combined with a progressive leverage ratio. However it is important that there is not much chain stretch on a 4X race bike to allow for explosive acceleration out of the gate. 4X racers want an agile almost twitchy bike.
Pyre:
The axle path is similar to the rampant, again the rearward axle path allows for good bump absorption, and optimal pedalling efficiency, but the axle path arcs forward half way through the travel to minimise chainstretch and pedal kickback which is of highest importance on an XC style full suspension bike.
Rune:
The rune has a more rearward axle path to make the bike more stable at speed over rough terrain than the other 2 bikes in the VF4B range, as this it more important for a trail riding / light freeride bike. The pedalling efficiency will still be great by using chain tension to help reduce pedal bob, all tho there will be slightly more pedal kickback than the other designs (partially because of having more travel).
