I have a crack in the rear derailer hanger on my Cinelli that has gone un-noticed for some time could anyone let me know if this is fixable, e.g welding, glueing or anyother options.
What approximate year of manufacture is your Cinelli and what company manufactured the dropout?
If an older steel frame, the dropout/hanger can be brazed or welded...depending on the location of the crack, degree of damage and skill of the frame builder doing the repair.
Alternatively, the entire dropout can be replaced. If a Campagnolo dropout, they can bought from the framebuilder, from www.campyoldy.com, etc. Cinelli-marked dropouts may have to be aquired from Cinelli. Depending on the year and type of dropout it may be difficult to locate exact replacements and substituting a new pair of Campy dropouts would be the way to go.
After inspecting your damage, a local frame builder will be able to advise you of the best course of action.