Can anyone enlighten me?
I'm moving an old (Circa 7 year old) 9 speed Tiagra cassette onto a Shimano R501 freehub. The Shimano spec says its suitable for 8,9 and 10 speed and it seems to fit well enough - until I get to the lockring.
The lockring is specifically for a 9 speed cassette with an 11 tooth cog. The problem is the depth of the thread of the lockring. When I fully tighten it, it appears to screw down onto the outer seal of the freehub, creating a drag effect ie. the cassette wont rotate completely freely and it results in the cassette failing to keep up with the freehub and the chain becoming loose when freewheeling or back pedalling.
Having looked at an more modern 10 speed Ultegra lockring, the body of the thing with the threads on is not as deep i.e. it wont foul the freehub seal.
My question is whether this sounds plausible and if so, where can I get a modern 9 speed lockring for a 11 tooth cog??