BEARING DIAMETERS ARE AS FOLLOWS;
FRONT
601B6005UU BEARING-BALL,#6005UU
Dimensions - d (inside diameter) 25mm
Dimensions - D (outside diameter) 47mm
Dimensions - B (width) 12mm
REAR
601B6304UU BEARING-BALL,#6304UUC3
Dimensions - d (inside diameter) 20mm
Dimensions - D (outside diameter) 52mm
Dimensions - B (width) 15mm
with that said, and to make the H/f tire machine happy, you want a 3/4" threaded rod, which will work on both wheels just fine.
The H/F I have, is actually threaded 22mm, but a 7/8" bolt, with a wrap of teflon thread tape, will thread into it...
I made a screwed in adapter for mine, and a pals, by elding a 3/4" SAE nut, to the head of a 22mm bolt, and it allows me and him to insert a piece of 3/4" all-thread, to use as a center post... with common nuts and washers.