back when I was cycling all the time and a svelt 275 lbs I could run my CAAD 7 on 700 by 23... well what with the baby, new job moving and all I havent biked much in months. I got a blowout and I assumed it was from forgetting to check my tire pressure. Got the tube replaces and it blew out again a week later (about 100 miles) and this time I was certain it was fully inflated before I left. (100lbs) The LBS kind delicately mentioned I might want to get 25s for the rear to spread the load. Which I did. And he took the time to show me how to replace a tube, which will be great next time as the last blow out lead to a very long walk.
Good news is I learned a new skill. Bad news is I feel like I am going backwards having to get fat tires.