On 21 Nov 2005 08:29:31 -0800, "damyth"
wrote:

So what exactly needs to be replaced to upgrade 1999 9s to 10s? A
shift disk, maybe some lever springs, chain and cassette, is that it?

A shift cam, which necessitates removal of the through bolt, makes
for a complete conversion. Often the cam is omitted because it's
tricky to get to. The Cam is inexpensive.