I bought this but it doesn’t really fit:
https://www.tradeinn.com/bikeinn/en/unior-suntour-freewheel-remover-3-4-tool/137598206/p
I’m not familiar with that system but here is park tools freewheel removal page. Hopefully you find the one that fits as they have pics and measurements.
https://www.parktool.com/en-us/blog/repair-help/freewheel-removal-and-installation
Thanks, super helpful!
Edit: pretty sure I have the right tool based on this (fr-3) but the teeth don’t go in the notches super far. I have to take the whole axle out to get the tool in, but then it’s not budging. Maybe it’s just super tight
Are you using a chain wrench/chain whip? The lock nut should be a standard thread (meaning turn counter clockwise to loosen) but you need to hold the cassette still with the chain wrench.
I like to hold the two about thirty degrees apart and grab both with one hand and squeeze while using my other hand to hold the tool in place.
Yeah I have a chain whip. I’ve previously only done HG hubs but this tool just doesn’t seem to be seating well when I try it. It’s a pretty old bike so maybe I just need to persuade it in to position more before I try to turn it. Might get the cheater bar out of the stand tomorrow perhaps