How to remove old glue from tubular rims?

[Peachy!]

That's good news. Red usually means shellac which along with tardigrades can survive a nuclear war!

Meths ought to dissolve the old shellac stuff, no?

I had just removed some shellac off of on an old Fiamme rim, wiped off real easy with acetone..

 

[Midlife]

Every day is a school day, will remember acetone for Shellac

 

[captnslow]

Some stuff out of the US of A called 'Goof Off' does the trick every time. Doesn't matter if it's glue or shellac. No scratching and leaves the rims as clean as a whistle, to the extent that you will be able to tell if the person who installed the tyre you have removed bothered to sand the rim first to provide adequate glue adhesion...