I have a B3030 with the 72" MMM and R4 tires. Swivel wheels all four corners and it is a very good cutting mower. I have never had any problems with power running the 72" mower.The swivel wheels are solid rubber.subzero said:is this a good set up.. reply if you are using this set-up..what about the castor wheels on the mower, are they they svivel type with air in the them..