Joined: Feb 2009
Posts: 85
Likes: 0
From: BC
Bikes: Nishiki Superbe, Marinoni Custom SL, Giant TCR Hybrid, Giant TCR 0 Team, Colnago Dream Plus, Trek 2000, Centurion Ironman Master. Giant Cypress-R CX, Kona Muni-Mula ("Colonel Mustard"), Giant TCR2, Giant Defy Alliance 0, Giant TCR Advanced SL 1 ISP
The shim is actually a sleeve that is part of the handlebars - very common type of construction in that era. What type of stem are you using? For example, if you are using a Cinelli stem (26.4 mm) with that Japanese Champion handlebar (25.4 mm), it certainly won't tighten enough.