Hi,

I got this MTB and I want to change the cassette. However I cant find the name or the tool to open the sprocket lock ring. The normal Shimano tool doesnt fit. Anyone seen something like this?

Not A Cassette. its a Freewheel , with those splines in the Body, you unscrew it from the Hub.

no purpose in taking it apart, lots of tiny bearing balls to lose if you do.

Just buy a different freewheel , nobody sells separate freewheel cogs anymore , anyhow.

Probably this tool will remove it:



Perhaps your LBS or bike co-op may have one?

Not laughing at him ok is just a commentary in general. Kids see something and they think in cassettes, like bicycles had their parts invented like 5 years ago. I even have noticed the same behavoir in store mechanics and sales people in lbs, is just amazing.

As others pointed out, you have a freewheel, not a cassette. A normal Shimano freewheel tool (and a big wrench or bench vise) will remove it.

Consult the guru: https://www.sheldonbrown.com/freewheels.html