a row straddling dual wheel arrangement for the drive wheels of a self - propelled combine harvester comprises two highly offset dished wheels , back - to - back with central mounting flanges abutting , clamped to the combine drive axle wheel flange by conventional wheel bolts . temporary installation in the axle flange of pilot studs and use of a retainer rod facilitate mounting and dismounting procedures in which the wheels may be handled essentially individually and then more safely .