A whole bunch more speed and power. My first thumper was a Kawasaki 350 Bighorn, had a 450 knobby on the back, and I used to run the big Regency sand dunes on it. Throttle stayed wide open most of the time on the plains in 3rd gear, screamed it in 2nd to climb the dunes. Went off the top of the master monster dune still getting about 25mph. (broke the frame right through both gusset plates), but all that throttle and drag makes motors cry for Mama. Sand can quickly dissolve a chain too.With tires it takes a lot of speed and power to climb a hill of sand.