I would like to know if they make tire tubes for larger people. I weigh 297. The tires work great for me but my wife is like 100 lbs more then me. I was trying to get her into rideing so we could lose weight. Well we went and rode around my bike (Mt. Fury) we took turns riding it and everything was fine. The next day I took my bike to a park and I was only able to ride about half a mile. I did notice that the tire was low when I got on. I told her it didn't go flat because of her. But I would still like to get a tube that will hold up. ANy ideas.