I recently purchased a set of Panaracer Urbanmax 700x32mm tires and after mounting them, found them to be only 30.5mm wide compaired to my other, supposedly identical, pair that inflate to 32.8mm. I bought one extra tire as a spare, for my high mileage rear tire on my old bike and am dissappointed that it is so noticably narrow, in comparison to the old one. My rims are identical in width Mavic T520 and Mavic A719. I wonder if any of you have noticed a difference when buying tires a year apart, hoping to have a match only to find them totally different? I like the urbanmax (old width) but am troubled that they changed. I wonder if Panaracer is using a different mold....or what.
Competitive pressures have often led to inaccuracy in width measurement. Here's how it works: Suppose you are in the market for a high performance 700 x 25 tire; you might reasonably investigate catalogues and advertisements to try to find the lightest 700-25 available. If the Pepsi Tire Company and the Coke Tire Company had tires of equal quality and technology, but the Pepsi 700-25 was actually a 700-24 marked as a 25, the Pepsi tire would be lighter than the accurately-marked Coke 700-25. This would put them at a competitive advantage. In self defense, Coke would retaliate by marketing an even lighter 700-23 labeled as a 700-25.
The trouble is, I could less how much my tire weighs ( within reason) in fact, what I wanted was a matching wider tire that gives me plenty of cushion. I have no trouble riding fast enough to suit me with a 32 mm tire pumped to 95psi. What I didn't want was some skinny, lightweight tire that sinks in soft road shoulders and blows out on the least bit of roadside debris. It seems the companies that misrepresent are shooting themselves in the foot, so to speak, if a rider wants a wider and heavier tire.
I guess what peeves me is that I purchased three tires, two for one bike and one to replace my worn rear tire for another. The trouble is, it looks goofy with one narrow tire on the rear and a wider semi worn one on the front. I guess I was just surprised that they changed not only the width but the profile also. Its not only narrower but it is very round in profile (thats good) but not what I expected. Guess I'll just have to purchase a matching set of something else and return my third tire or save it for a spare on my other bike.
I've found Panaracer to be about the most accurate in its labeling. My 32mm Paselas also measure about 30.5, but the 32 Michelins I had previously were only about 27, and my 28mm Avocets were just short of 25mm.
Panaracer relabeled some of its tires a couple of years ago, so the "35mm" Paselas I had on another bike went up from 30 to a hair over 34, and I hear the 37s are really 37. And Rivendell (www.rivbike.com) is always within half a millimeter with its RolyPoly and Ruffy Tuffy tires.
I am using 36 spoke T520's and A719's with 32 mm Urbanmax tires at 90-95 psi. I believe these rims are made for touring bikes and tandems and I don't plan on anything too wide as I think the max is 37mm with my rims. I read all of the posts and I believe the rim cracked due to a combination of things but the wider tire on the rim made for narrower tires probably contributed. Aluminum does fatigue very quickly and will crack if it bends beyond a certain point and often catastrophically. Perhaps the rim was defective and maybe corroded or even damaged by brake pads. When all of these things, combined with a too wide tire and a heavy load came together, I suspect the tire bead came unseated and the tube, under pressure, blew, cracking the rim in the process. I have read about high volume truck tires blowing and killing people standing next to them, so I am not surprised at the damage in the photos.
I am about 255 and have been riding 700 x 28 (Conti Ultrasport) and 700 x 23 (Spec Mondo) exclusively for the past year on roads in Texas. I tend to steer around debris, holes, cracks, ect when possible but still hit something hard on just about every ride. Our club rides tend to be primarily on less traveled countryside roads so there is always rocks and gravel. I have ridden about 3000 miles and have had a total of 2 flats, neither of which resulted in immediate deflation and the need to change during the ride. A little air got me back both times.
My point is that I would not let a narrow tire scare you from a durability point IF you are primarily doing road riding in typical settings. However, I only ride on paved roads, so your point about sinking with narrow tires, I can't really address. The Conti Ultrasports were very comfortable at about 110 psi, IMO. They are noticibly larger than the Specs.