cyclezealot

You just can't explain.. About once a year you go through a string of flats that just don't make sense. When changing flats, I am in no hurry. I painstakingly take the flat apart and search for why it happened. So, I go through a series of Three flats. After maybe having no flats for a whole year.
Flat One. My bike buddy has a set of gloves, I don't . So he performs most of the tube change. No signs of any objects lodged in the tire. The rim and rim tape seem smooth to the touch. . We find a small pinhole lake facing directly away from the rim. The tire goes in easily .I replace it with a new tube. . Flat two. On the way home, my tire starts to repeatedly loose pressure. I make it all the way home. Before the day is out, the tire is totally flat.
. I change it carefully. Another pin hole leak. (Again , the pin hole faces directly outward away from the rim.) But, in a different location from where the last pin hole leak was positioned . Again , I replace it with a new tube. Installing the tube goes easily.While inserting the new tube it installs easily . No suspicions of the tube being pinched during its installation.
. Flat 3. Next morning it is again flat. Again in a different location . A small pin hole leak facing 180 degrees to the rim. The interior of the tire seems smooth, no signs of objects having punctured the tire.
What is up. ? Between the second and final flat , the bike might have been ridden 10 miles.

cyclezealot

I suspect the tire's casing is getting thin, Even though to the touch it seems fairly thick. The thread seems pretty much intact. Maybe the tire has about 4000 to 5000 miles on it. at most. What the heck. Just throw out the tire and rim tape and say the tires had a good run.? I am getting a bit tired of turning new tubes into used tubes.

FBinNY 

Unless you systematically mount the tire in the same place, ie. label at the valve, I suspect that all three flats were caused by the same shard of glass or similar embedded in the tread. You often can't feel these running your fingers along the inside of the tire because they withdraw back into the tire itself, then when riding get pushed through.

Search for the offending object from the outside by rolling the (removed) tire between your fingers to open any cuts, and see what's hiding there. Odds are that you'll mind multiple tiny shards which you can pick out with your fingernail, or a small pick of some kind.

It helps to have a reference, so you know where the valve is on the tire and can line up the tube along the tire and localize the area to check, but I always take a moment to check the whole tire while I have the chance.

Bill Kapaun

5000 miles is probably time to toss it anyway.

Is the pin hole the same distance from the valve stem?
If you had a tiny piece of wire protruding in the tire....and not removed-
Patch the tube, but flip its "orientation" and you have another pin hole. an equal distance from the valve.
Swab the inner tire with a cotton ball. IF there's a tiny wire, it'll tend to catch the cotton.

cyclezealot

FB in NY et al.
. I did carefully measure the location of the pin hole leaks in the tubes as related to the rim. All three were in different locations . That is why I am baffled. I would obviously agree, throw out the tire it's not worth it. But, I've had thinner casings that performed OK and the thread is not all that worn. Could be, bad tubes. but three of them. So glad that these issues , normally , only come up but about once a year. But, then I have three bikes. The bike in question gets the greatest use. When I change the current flat, I will give the swabbing idea a try. The pin holes have all been at different locations , as I said.

spdracr39

Could you be repeatedly running through the same patch of debris on the road/ path ? Just trying to think outside the box.

FBinNY 

Now I'm baffled. You describe the puncture as being away from the rim side, more like center tread in the tire. So, why are you comparing the location to the rim? I know that it's easy because of the valve, but there's no assurance that the tire is oriented the same way each time, unless you make it so by always mounting a reference of some kind at the valve.

Since the puncture is on the tire side, it's reasonable to assume the cause is there too.

take the time to examine the tire carefully, flex every little nick open until you can see clear to the bottom and verify that there's nothing embedbed there.

cyclezealot

FB thanks. I appreciate being baffled together. I have carefully flexed the tire, looked for cosmetic damages on the outside. Measured the locations of the pin leaks. All different. All leaks perpendicular to the rim.. Facing in the direction to the road. ( Side punctures might indicate problems in packing the tube.But, I have none. ) My club is frustrated with the way I change flats, so I tell them to go on ahead. .. I change flats slowly and Methodologically , looking for why it happened.
Flats are no big deal , but I hate to throw out a tire before its time. It must be a shard of glass that only rears its head under 100 pounds of pressure or I over estimate the depth of the casing. Some roads I ride on are pretty much strewn with debris.
How much miles does one expect to put on your tires before you throw it away. ?

lectraplayer

I saw another guy say about 5000 miles or so. I still think it's in the tire itself. Put the logo on the tire with the valve stem each time and see if the pinhole still moves around the rim.

FBinNY 

I have no magic miles number. I use tires until they wear through to the under tread unless a big cut, or age weakens the body plies until they look ready to let go.

Rear tires usually last about a year or so, but I've had fronts last over 20,000 miles.

BTW - the flats might be unrelated to anything except a run of bad luck. I've gone over 3,000 miles between flats, and have also had 3 unrelated flats the same week.

Black wallnut 

I am happy if I get 2500 miles from a premium Specialized Armadillo tire, on the rear, twice as much for a front. Are you lining up the valve stem with the same exact spot on the tire each time you change the flat? I line mine up with the center of the label while paying attention to the rotation direction arrow, not that direction matters for tire performance but it sure does when it comes to finding small punctures. Next time before you dismount the tire from the rim mark both the ds and valve stem location on the tire. When you find the location of the puncture on the tube lay it over the tire and identify a 2" spot on the tire where the puncture is and closely inspect the tire at that point inside and outside. You will find the cause of the puncture.

Looigi

I'll just mention that if getting flats occurs randomly, they won't be spaced evenly in time or miles and the period between flats will vary so that sometimes flats will occur relatively close together and at other times they'll be long stretches with no flats. For a thorough description and to calculate probabilities of bunching see: Poisson distribution - Wikipedia, the free encyclopedia

cyclezealot

That I do. ..

cyclezealot

I've liked Armadillo's too. But, god, are they hard to pack. I usually loose some skin off of my knuckles.

Dfrost 

I once had a series of flats with no obvious cause - until I looked at the inside of the tire and saw a slice about 1/8" long in the casing interior. Apparently that slice was "chewing" holes in the tube.

davidad

My nemesis is the radial ply tire steel wire that penetrates the tread and is very hard to find.

cyclist2000

When I only had one bike, I replaced tires every year since I put about 6000 miles on them per year.

TrojanHorse

me too, got three flats in one ride from one of those and they're tiny! You just about need the cotton ball to find it.

I tend to cut tires before they totally wear out but anything over 2k for a rear and I'm content that the tire did the best it could.

Bill Kapaun

Another thing to check out-
On an CL flipper I picked up, the tires/tubes were OLD!
I patched a couple pin holes in the tube, inflated and developed a couple more pin holes.
The rubber had deteriorated? enough that there were tiny "spots" that could best be described as "CARBON".
The new patches would cause the tube to stretch a bit differently and pop the little specks.
I was pretty much getting 2 new pin holes per patch.

Examine the pin hole itself and see if there is a tiny, hard/crystallized piece of rubber on the edge.

cyclezealot

Looks like this could be filed away with today's OP.. Flat Tire , No puncture. Yesterday, I passed by my favorite bike shop and told them my story. The mechanic said that is weird. But, in some instances, take off the tire, turn it inside out and bend the tire so as to cause a crease in the casing. Should any piece of metal be present , it might show itself in the fold. I found two small thorns . But on the outside of the tire, the puncture holes were so small they could not be seen. Maybe I should buy tires with thicker casings. The Tire is a Performance Forte.