MRGolfo

Sorry for the ignorant question. When I purchased my bike 2 summers ago, I purchased 2 replacement tubes. It is a 27x3/4-1,700x18-25c. What does that mean? It's time for me to purchase new ones since I used my last tube. I know i need an extra long stem since I have a Velocity Rims that seem to be extra deep.

Also, since we are talking about the wheels, how long do tires normally last. I know part of it depends on the terrain. Just asking in general because the tire seems to be rotting on the sides.

twahl

Tubes have a bit of variance allowed, so a tube that fits a modern 700 c tire will also fit an older 27" tire. Yours are marked to fit either 27" by 3/4" - 1" wide, or 700 x 18 - 25 mm wide. The tire should have marking on it, I suspect 700x23. Most places will have long stem tubes available for you.

As far as tires go, everyone has their personal preferences. Dry rot isn't a good sign and usually won't happen quickly unless the tire is exposed to sun. I ride enough that mine will be "crowned" before they dry rot, and when they're getting thin it's time to replace. Depending on the tire you might get anywhere from 500 - 2000+ miles on a tire. Dry rot may not indicate that the tire really needs to be replaced, but tires are pretty cheap for the most part so replacement isn't cost prohibitive.

MRGolfo

Here's another question. What's the def. between a folding and clincher tire?

twahl

Folding tires may or may not be clinchers. Clinchers use a tube, while tubular tires don't. I believe all tubulars fold, but not all folding tires are tubular. Tubulars are like a tire and a tube combined, and require a different rim. Clinchers may or may not fold, depending on the bead material and construction. Folding tires are easier to store and carry a spare.

brianappleby

folding is a TYPE of clincher tire.

Folding tires have a bead made from kevlar string. The bead is the thick part on either edge of the tire that "grabs" on to the rim. The alternative is to make it from a steel cable. There are pros and cons, but folding tires are easier to store, and are lighter, and ( i think ) more expensive.

chromedome

twahl made the answer difficult to understand.

Most any road inner tube will fit most any road tire. Doesn't really matter if its 700c or 27" as far as tubes go. Since the change size and shape when they are inflated, they conforn to the inside of the tire. But TIRE sizes are important. And you've already figured out the valve length bit for yourself. That really messes people up.

Tires need to be replaced when they become so old that the black rubber is peeling off the casing of the tire, or when it rubbs off with your finger. Hopefully, you ride enough to wear out your tires. You'll know when they are getting close to being worn out when no tread on them exists. When you have them worn down to the casing, its time for new ones. At that point, you may as well replace both tires.

I seriously doubt if your are using sewups (the tubular tires twahl was trying to talk about) so I won't go into them now. Foldable tires are ones that can be folded over top of themselves so you can take one with you on your rides. Why take an extra tire with you on a ride, you wonder. Mostly for longer tours where you may not be around bike stores to be able to buy a new one if needed. They are foldable because they have certain kinds of beads (the edge of the tire that interfaces and seats within the rim; that's what the clincher bit is, the tire "clinches" the rim) that can be bent over without being damaged. To know if a tire is foldable, go to the bike store and look at the display of tires. If a tire is hanging on a hook on the wall, its not foldable. If its folded up and stuffed in a box, it is foldable. Foldables tend to cost a few bucks more.

If you dont have a reason to buy a foldable tire, dont bother.

Over the last 40 years of cycling, I've had the oppurtunity to try many different brands and styles of tires. I've used American, Japanese, Taiwanese, Chinese, and European tires. I always trust Continental. Their the most trustworthy and well made. I've never had a problem with a Conti, through racing, commuting, touring, training, whatever. And they offer so many different varieties, you really cant go wrong with a Conti.

If you want to know about tubular tires (sewups) ask. Its an entirely different type of tire and rim, and they have specialty applications. If you are still fairly new to cycling, you probably dont need to be concerned with them yet. Learn everything there is to know about your bike, then move on from there.