I rescued a bike from the trash and want to convert from 7 speed to 9 speed. The biggest sprocket has "Lock Ring Type" 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 "Lock Ring Type" 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). Cassette or freewheel

  • It is bike24.com/p2273122.html Commented Jul 18, 2020 at 8:41
  • 1
    "megadrive" sounds like a knock off of the Shimano MegaRange freewheels with a very large low gear.
    – Criggie
    Commented Jul 18, 2020 at 8:44
  • 1
    Pure speculation on my part but perhaps disassembly requires removal of the ring marked "Suunrace M1" using a suitable (but unknown) tool, instead of the typical 2 pin spanner on the more inner ring.
    – mikes
    Commented Jul 18, 2020 at 20:47

1 Answer 1


It's a freewheel with some words on it. The tool splines will always spin with the cogs if it's a cassette.

  • Do you expect the “lock ring type” to just be some nonsense marketing? Commented Jul 18, 2020 at 13:05
  • 2
    I suspect it's some kind of knockoff off the Shimano "Mega 7" design, which used a lockring instead of threaded cogs. sheldonbrown.com/mega7 Commented Jul 18, 2020 at 15:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.