I've got a 12 year old Trek 2500, which is in great shape but one of the original stickers on the seat tube just won't come off. It's a big wraparound job, and I'd leave it except that it was peeling a little when I got the bike so I've been trying to remove the whole thing ever since. I had some luck getting a couple smaller decals off with goo gone and careful work with a razor blade, but this one is persistent and I'm leery of gouging the paint if I get too aggressive with a razor. Anyone have any ideas? I'd like to use some chemical to soften up the glue's hold on the frame, but I don't know what to try besides goo gone.

any type of oil product will dissolve glue.
I'm not sure how well it would work on old glue, however.

Try warming the sticker with a hair dryer. It usually doesn't take too much heat to soften the glue; the sticker should then peel right off. Any residual adhesive can then be removed with WD40 and a soft rag.

Regards,
Bob P.

+1 for hair dryer