I have an 12-15 year old mens Giant Cypress bicycle. I am trying to find out what exact tire size originally came with the bike. I have been riding on smaller replacement tires that now need to be replaced. The smaller size that I have been riding on is 700 x 35C - 28 x 1 5/8 x 1 3/8. These tires are smaller (thinner) than the original. I would like to know the original size and if there are any options besides these current tires which I never cared for anyway. Thanks, Frank
The 2005 Giant Cypress came with 700x38c tyres. https://www.bicyclebluebook.com/value-guide/product/92884/
Large volume tyres are growing in popularity over the last couple of years, so you should be able to find many good options in this size.