Abstract: An adjustable spindle assembly with a spindle housing, a grooved spindle shaft rotatably connected to the spindle housing, a pulley connected to one end of the grooved spindle shaft, a mow ball rotatably connected to a second end of the grooved spindle shaft, and a string carrier assembly connected in between the spindle housing and the mow ball. The string carrier assembly includes a pair of string guides and string holders for securing cutting string to the string carrier assembly without the use of tools. In addition, the string carrier assembly can be adjusted between the spindle housing and the mow ball without the use of tools.