In Search of Tire Recommendations for my Colorado LT

[MMcG]

I need to replace the tires on my Serotta Colorado LT and I'm hoping you fellow list members can help out with some recommendations of good quality, affordable tires for my ride.

I primarily ride for excercise and partake in one or two charity rides per year - usually 50milers so I guess I'm looking for a durable, fairly fast rolling, training type of tire.

I was thinking a 700x25 tire would be fine for the riding I do. What do you think? Will a 700x25 fit the LT frame fine?

Current tires are Continentals and they are starting to crack a bit (they may be the original tires).

I'm on a low budget these days, so recommendations of something on sale would be great. Even better yet, if you've got some tires that you are no longer using but have plenty of life left in them, I'd be happy to pay you a fair price for them.

I welcome your thoughts and recommendations.

Thanks in advance.

Mark