Originally Posted by DieselDan
Sounds like a dry jockey pully bushing. The jockey pully is the upper pully and floats to allow for indexed shifting. When it is dry, it sqeaks like shoes. You'll have to remove it, and apply a tiny amount of bearing grease to it.
Second that. I bought a used 105 and it squealed like crazy. Squirted some oil on in the bearing and its fine now.
__________________
Il faut de l'audace, encore de l'audace, toujours de l'audace
1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1