Last weekend we had the jetski out, and I noticed the tires have gotten worse. The side walls have had minor cracks for a while, but now the tread has cracks to the cords. The load is an 850# ski, plus trailer w/ storage box. Where we normally go is 50 miles round trip, 65 mph. What do you think... Will it make on our 800 mile (round trip) vacation in a few weeks?