Greetings. I have two pair of 9-spd Ergo levers - 1999 Athena and 1998
Chorus (which look like the current design, not the first generation
Ergo's).
I'd picked up a 10-speed index disk for half price some time ago. Once
I'd acquired the Chorus shifters, used, I decided to rebuild them (new
g-springs and carrier) and convert them to 10-spd. I ordered the finger
lever ratchet along with the springs...
I couldn't get the index disk to fit. It seems the keyhole into which
the bushing must fit was much smaller than the key on the bushing. I
looked at the parts diagrams for the 1998 Chorus and the 1999 Athena.
The bushing had the same part number. (Note - no problem with fitting
the finger ratchet on the bushing, which was unfortunate. I had to pull
the finger lever assembly back out again to put the 9-spd back on.)
SO, is the bushing the same part number but a different shape after a
certain date? Is the "convertablility" by changing out just those 2
ratchets on 2000 or newer levers? Finally, if I bought a "new" bushing
(for my next re-build), would I then have sufficient parts to complete
the conversion?