Spindle Assembly for Bad Boy 48 54 61 and 72 inch Deck Extreme Outlaw XP. Although this is not an OEM part, its quality can be compared to the original, yet it is more cost-effective than the original. All our internal specifications meet the same. Compatible with Models: 48″ 54″ 61 Deck Bad Boy Stand-On. Compatible with: 54″ 61″ 72 Deck For Bad Boy Outlaw, Outlaw Extreme, and Outlaw XP. Package included: 3 x Spindle. Lawn mower spindle help your lawn mower pulley system perform, optimize your lawn mower cutting power and ability. Why need to replace THE MOWER SPINDLE? The spindle assembly is responsible for turning the mower blades. They are powered by drive belts and pulleys, which may cause some wear, bending and deformation under prolonged use. Damaged and unbalanced blades can further damage the spindle assembly. For safety reasons, so they should be replaced.