Dual mode undercarriage for tracked vehicle

A vehicle with a frame connecting a driver wheel, an idler wheel and mid-roller wheels, an endless track belt being tensioned around said driver wheel and said idler wheel and being in contact with said mid-roller wheels on a lower run thereof, said mid-roller wheels being arranged in boogies, including a front boogie, a middle boogie and a rear boogie, said front boogie having a first pivot axis, and said middle and rear boogies forming a tandem having a second pivot axis, wherein said first pivot axis and said second pivot axis act are load transfer pivots.