1 inch
harley sportster front axle torque specs
1 inch.
It should be one inch.
36 mm
31" from top of yube to axle
60 ft/lbs.
3.4" oem part 41110-79A
60 - 65 ft/lbs
100 ft lbs
23" measured from center of axle to lower bearing surface (where the stem meets the TOP of the LOWER triple tree).
Both Harley Davidson softails and hardtails look very similary. The main difference is really a matter of the suspensions. On the softail model there is a rear suspension that makes for a much smoother ride than the hardtail. The hardtail frame is all one piece in which the rear axle attaches directly to the frame.
You should have a 1" axle front and rear.