It is a tough call with out looking at them,but considering the age of the tires and if pulling it with a trike or motorcycle,it might be best to just replace them.Its kind of tough sitting along the side of the road miles from home,not knowing where to get a new tire from and on a trike with limited space to carry a tire,if you don't have a spare with you.I don't carry a spare on my aspen sentry,or for my bike (now trike) and have had a flat tire on the bike 300 miles from home.Its not the most fun situation to be in.