Donepart 6203ZZ Ball Bearings - C3 High Speed - 17mm Bore, 40mm OD, 12mm Width Bearings for Motor Bike Wheel Pump Tractor (4 PCS)

Q: Can 6203zz bearings replace 6203-2rs? if they can which one is better for using in spindle of a zero turn mower?

The dimensions of 6203ZZ and 6203-2RS are the same. 2RS can provide better protection against contamination, but the rotating torque will increase, ZZ is the opposite. So the choice of 2RS or ZZ depends on the application and environment of the bearing.