Track Cog Threading
From Pvdwiki
ISO Track cogs are threaded 1.375" x 24 tpi, Just like a bottom bracket. threads should be at about 7mm long.
ISO Track lockrings are threaded 1.29" x 24 tpi LH, a left handed thread.
exeptions:
campy lockrings are 1.32" x 24 tpi LH
French is 33mm x 1mm LH
