+1 to staehpj1's post! And thanks for the link to the video on how to curl a non-folding tire to make it smaller. Now I won't have to try to describe it in text.
To add to rvklassen's post: A foldable tire can truly be folded, not just curled. The bead is not stiff at all, and can be folded sharply without damage, and won't tend to hold the folds when opened out.
I find however that the folding tires are
harder to mount, because they don't hold their shape in the process like wire-bead ones do. Instead, the folding tires tend to curl into figure-8's or turn inside out and things like that when you're trying to mount them. Unfortunately it seems like none of the better tires come in a wire-bead version anymore.
I never carried a spare tyre on a single. Living dangerously? Perhaps. It is rare (but not unheard of) to damage a tyre beyond the point of usefulness - it happened to us the other week for the first time in 40 years of riding - tear just above the (wire) bead: probably due to a failing rim; any really bad blowout means a new tyre but most can be booted until you get to a store. However, the tyre you get at some random store won't necessarily be a tyre you like. Normally you can see when a tyre is approaching end of life, so it's not catastrophic.
So true. Even a 1/4" cut, booted well, can be perfectly reliable, even on the sidewall, even on the front. Pieces of Mr. Tuffy tire liners make good booting material, and you don't have to glue it to the inside of the tire. The pressure of the tube against the inside of the tire will hold it in place plenty well without glue or adhesive. Pick a tire-liner width a little wider than you would use for your size of tire. If the hole pretty big, use two pieces of the tire liner, one over the other. We've ridden tens of thousands of miles on booted tires, and they have never been a problem. In fact, after booting one place, we have, a few time, gotten a cut in another part of the tire, ending up with two boots, before the tire is worn out. Yet after buying and maintaining somewhere near 200 tires for myself and my family over the decades, every single catastrophic or near-catastrophic tire problem we've had has been with a
new or nearly new tire (indicating a manufacturing defect),
never a booted tire.
For the ultra-bad tire situation (like a blowout on one of the new tires I was talking about), you can carry a piece of a thin, worn-out but otherwise undamaged tire, cut to maybe 2"x3", and with the beads cut off, as booting material. Ride the tire until you get your first chance to replace it.
This tire, with the pencil stuck into the hole to show the size,
was booted and ridden with the cut for the last 1,500 miles on the rear, including bombing down a lot of curvy mountain roads, until it was worn out. It was booted with two 1.5" strips of Mr. Tuffy tire liner (our usual boot material), oriented oposite directions, so there was no bulging at full pressure. I took the picture just before putting the tire in the trash.
This one
is on a bike which doesn't get ridden much, so although it has somewhere near 2000 miles on this boot job, it has been this way for many years.
The following front tire has the biggest sidewall cut I've ever booted. The boot job made it safe for the last third of its wear life.
A friend who's new to cycling had the same as this happen to his tires when they were relatively new:
and the shop told him the tires were toast and that he had to buy new ones. I don't know if they just wanted to take advantage and make money, or if they were just ignorant, or maybe just didn't want to be blamed after something unrelated happened, or what. What's frayed here is only the outside edge of the fabric that protects the bead area from tire levers.
All the fabric behind the side of the rim is perfect, and I rode this tire thousands of miles more.
None of these (and there are plenty more) have ever given us any problems like the
new tires did that started coming apart from the inside with 200 miles or less, sometimes on the very first ride, evidenced by the lumping and a bad S-bend developing quickly, which if not caught right away, results in a blowout. The last tires I had this happen on were a pair of
new Vredestein Fortezzas (not even 200 miles on them) at 95-100psi (way below their rated max), not seconds, and not cheap tires, although not the most expensive either. Unfortunately I didn't take pictures before throwing the tires out.
We usually wear the tires out until the strings are showing, like this:
After retiring one that was more worn than this, I cut across it to see what was left on the inside, and I was pleasantly surprised that the carcass was really unaffected, all still there. Some will say you get flats more easily when the tire is so worn. In this case however, it's a Continental Grand Prix 4000, which has a vectran breaker layer inside (supposedly better than kevlar), and that breaker layer is
not at all affected by tread wear.
The strength of the tire is not in the rubber, so wear or cuts on only the rubber are inconsequential. Cuts to the carcass need to be booted, and if done properly, can be at least as safe as a new tire.
