I've got a Schwinn sprint that I received from a neighbor and I'm not sure how old it is (80's or early 90's)
The serial number is 6049593 and head badge says 0555 ( I'm not 100% sure about the last five because it looks like the stamp didn't go all the way. What year is it?
The last digit on the head badge indicates that it is either a 1985 or 1995. I don't think the Sprint was available in '95, so it is undoubtedly a 1985, being made on the 55th day of the year. What you need to do to confirm is check out the Schwinn catalogs that are available online or on several Schwinn-related posts on this forum.
The Sprint was a lower end "leisure" bike, not intended to racing or serious road bikers. Having said that, it doesn't mean that it is a bad bike, just on the heavy side and not especially collectible.
Actually, I am getting much better at quickly finding information and my memory is getting filled up with lots of bike-related knowledge. Probably enough to be dangerous.
I have learned tons by reading Scooper's posts both here and on the Schwinn Forums. He has forgotten more about Schwinns and bikes in general than I'll ever know. His passion for vintage Schwinns is what has caused me to jump on the bandwagon.