In 2005, the XL Evolution V twin engine has been redesigned, having improved cooling, high-flow cylinder heads and lighter pistons and connecting rods. For the new models, the diameter of the rear axle is increased to 1.00 inch from 0.75 inch while a new swing arm was designed to accommodate the thicker axle. The bikes also have a new headlight with clear-lens, reflector-optics for improved lighting performance.