Originally Posted by
DiabloScott
When the tire is on a rim (clincher or tubular), the inside diameter stays the same as you inflate it and the outside diameter increases. The casing of the tire is cloth and the bias of the threads are oriented to allow this kind of stretching.
When the tire is not on the rim, the outside diameter (the base tape) stays the same and the inside diameter decreases as you inflate it; this is the opposite of what the casing was designed to do and it can be damaged if you inflate it too much. You might not notice but some of the cords could be torn and you'd have a problem later on. Inflating enough to just make a good gluing surface isn't going to be a problem of course.
The base tape damage wasn't my comment, but I have seen the edges of the tape pucker up after inflation off-rim. Makes for some fun experiments with old tires.
First, I did say it elongates. You seem to be saying it's not designed to, but I think we don't know that.
I also find it hard to see pucker as damage.
You hypothesize that carcass threads may be damaged, but is there any evidence of that? Any blowouts under the tape? Any hanging threads?
At least not in my experience.
Road Fan