Freewheel with lock ring, what is this? I rescued a bike from the trash and want to convert from 7 speed to 9 speed.  The biggest sprocket has &quot;Lock Ring Type&quot; printed on, so I assumed it was a 7 speed cassette (and I wanted to see if the free hub is a modern type that fits a 9 speed cassette).
However after taking the wheel out I noticed it looks like a freewheel rather than freehub with cassette.  Why does it say &quot;Lock Ring Type&quot; on the biggest sprocket?  Is this actually a freehub with a lockring that's unfamiliar to me?
I have included a picture (I removed the axle to have a closer look).
It's a freewheel with some words on it. The tool splines will always spin with the cogs if it's a cassette.