How are Type-C Freewheel cogs secured to the body


New Member
Aug 21, 2003
I was noticing on my 11-34 type C Shimano freewheel a ring outboard of the 11T sprocket. The ring has notches on the outside of the sprocket-but none inside the diameter. Is this a snap ring or a lock ring or a thin thread-on retaining nut?

Is the 11T a threadon typical of other Shimano smallest freewheel cogs or is it splined like hyperglide cassettes?