I still think of "decals" as water (or varnish)-transfer type, I guess that comes from my model car and airplane building days as a kid. Most later bike transfers are what are commonly referred to as "stickers", or adhesive-backed vinyl, mylar or something similar. Removing the two types can be a very different process. I'm an admitted sticker-freak, have drawers full of 'em, and constantly apply and remove them from all kinds of things (I even staring at a Peugoet-badged monitor right now). That off my chest, Mark's Vitus most probably has "stickers". With most stickers, if you can't pull them off you still have to at least pry up the edge in order to get solvent behind the sticker. A solvent strong enough to actually dissolve the sticker would probable be damaging to the paint or other things. The key is to dissolve or soften the adhesive that holds the sticker. There are two solvents that I've had success with. A product call "Goof-Off", available at most home supply stores, will work, but it's pretty strong so should be carefully tested first. Another product called "Bestine", which is actually rubber cement thinner and available at art supply stores, also works well. Bestine is not as strong, evaporates rapidly and is pretty safe around paint, plastic and aluminum. Using an Xacto knife, pry up an edge or corner of the sticker, being careful not to catch the paint. Using flat-bladed needle nose pliers, grab the sticker. Now, with a small paint brush, flood the area with solvent as you gently pull the sticker with the pliers. You have to continually apply more solvent as the sticker pulls away. The pliers part is pretty tricky because most older stickers are brittle so they split, crack and break easily. I sometimes use the flat of the Xacto blade and my thumb to grab the sticker. It takes a lot of patience, but works pretty well.
Wayne "Sticker Art" Bingham
Falls Church, VA