Flat and disgusted.
 

I don't mind getting flats. its part of biking.
But last year I got nine flats in a little over the last month of the Season.
This week I have had two,both within hours of each other.
There is never any object visible in the tire,not even a hole.
All the flats are directly on the inner tube mould center line.

HELP ! :)

Continental tubes are extruded in a single piece. There is no center line to split.

What is felt when fingers are carefully wiped through the tire carcass and across the rim channel, to feel the entire surface that is being pressed by the tube?

Hmmm, so eleven times in a row you didn't find and correct the cause of the flats.

"When you find yourself at the bottom of a deep dark hole, drop the shovel."

After checking the outside I turn the tire inside out and
rub the inside,now outside,with my fingers.
There is never anything there.

That is interesting.
Are you saying it happens that there are faults on that center line?

Carefully check the outside of the tire when it is fully inflated. Sometimes you can get a cut in the tire that is so small that the tube doesn't blow out, but it's enough to let the tube actually rub on the road surface. This can cause repeated flats, especially annoying after fixing one another occurs 20 miles later. The tire can be booted, but ultimately it needs to be replaced.

I've had this happen 3 times in 40 years of riding. It's really, really frustrating.

Definitely something to keep in mind. :)

Are you patching the same tube every time, or replacing it? If patching, probably just a defective or "tired" tube.
And if you are replacing,. Maybe switch brands.

Use a cotton ball, it'll snag on things your fingers might miss.

+1 And turn the tire inside-out, it will help open any small holes where wire, glass, etc. likes to hide.

got a photo of one of the damaged tubes?

Also saves your fingers from being sliced by a piece of glass. :thumb:

This is one place where being a little anal pays off.

Are you one of those folks who always lines up their tire label with the valve stem? That's a good thing. If you start having frequent punctures, you can match up the inner tube with your tire to look for the offending thorn or wire or whatever that caused the puncture. My last few punctures were caused by radial tire steel wires. Those pesky little things can be real hard to find and, once found, can also be real hard to root out. I've taken to carrying a tiny pair of needle nose pliers with me just for that purpose.

If you don't find that little devil and pull it out of your tire it can easily cause 2 or 3 (or more) punctures per week.

I once started getting repeated flats on my commute to work bike. Always in the same place. I never did find what was causing them. It had big, wide tires so I cut the valve stem out of an old inner tube and used it for a tire liner. That solved the problem until I got a real good deal on a pair of slightly used tires from somebody.

Thorn resistant/heavy duty tubes , stay inflated longer, by having more rubber in them.

Put those in a tire with a puncture resistant band in the tread, and I go many years with out a flat tire..

trade off is it weighs more..

If it is coming from the tire, replace the tire. Is it really worth spending all that time over a tire that may be defective in some way or just worn out? Also I was going to suggest rim tape too. It does sometimes slip and expose a hole.

ah yes, rim tape ...

https://cimg5.ibsrv.net/gimg/bikefor...c05e55a110.jpg

https://cimg7.ibsrv.net/gimg/bikefor...ccd220d39c.jpg

& this little bugger (broken tire bead) was good for 2 flats. didn't find it until the 2nd flat

https://cimg4.ibsrv.net/gimg/bikefor...d5b16adca8.jpg

Are these all with the same tire? And is the tube puncture in the same place relative to the tire every time? If so, put on a different tire to solve the immediate problem and go riding. Assuming no more recurring flats, either toss the old tire or spend as much time as necessary with a bright light, glasses or magnifying glass, cotton balls, tweezer, etc. examining the old tire until you find the culprit, depending on how much life is left in the old tire and how much patience you have.

I once had a small bit of wire in my tire, the length was less than the thickness of the tire, so it did not poke thru when the tire was dismounted, it only poked the tube as the tire was inflated and working. I found it because I had 3 tubes all with a puncture in the same place that I could line up with the tire, so I knew where it had to be. Finally by pushing in from the outside of the tire I found it. Wouldn't have bothered except the tire was virtually new.

Plus, it protects your fingers from wires and other sharp things. Also, go both directions with the cotton ball.

Sound advice.
I have two schwalbé Marathon Supremes now.

The reason I was being so tenacious is there was the possibility my drunk,drug addict neighbors may have been futzing with the tire.:)
I am moving next month.:)

Center top,or center bottom... two very different issues?

When removing the tubes, remember where the valve was with respect to the tire. Some people advocate putting the tire label or pressure rating at the valve, so you'll know where the vale was.

Then when you remove the tube and locate the hole, you only have 2 places to look for the cause.

Directing your search helps a lot for finding the problem.

Thanks all,some very good advice there.
Once I get my Schwalbe supremes on there I can start from zero flats.
After that I am bringing the old tire to my L.B.S..
If they can find a problem with the tire I will buy donuts for the whole lot of them. :)

I know cheap inner tubes can be a bother this way, they sometimes tear for no good reason. At the bike shop they have a couple of times thrown out entire boxes of bad batches of tubes, I can't remember the brand name at the moment. Try a more trusted brand next time, at least a different one. It's common to make tears in the tube when you put the tire back on, be very careful when using tyre levers. In most cases you can get the tyre back on with otu levers by pressing the walls of the tire between you fingers and making sure it settles well into the rim all round the wheel, then the last bit usually snaps into place with ease. Pump some air into a brand new tube and let it out again, it stretches it and its easier to get in place under the tyre. Most tyres with kevlar guard are acceptable, but the best this way is Schwalbe's Marathon line, I have had Marathon Pluss (optimal puncture resistance) and Marathon Green Guard. These are havier tyres, there are fimer and lighter ones like Delta Cruiser with kevlar guide.

Once I kept on getting short slits in my tubes, couldn't find anything wrong with the tire, replacing the tire and tube made no difference. It turned out that the tire liner had cracked and was pinching the tube. I had to inspect it by bending it out.

I've also picked up the tiny bits of wire others have, couldn't find them with bare fingers, cotton turned them up.

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https://en.wikipedia.org/wiki/National_Doughnut_Day

It is often easier to find the culprit if you start with the rim, tire, and tube all together.

Mark valve on tire, pull off tire and tube. Then locate the hole in the tube. Determine if the hole is tire or rim side, then inspect the tire or rim near where the hole was.

Sometimes one can dig out a piece of glass, only to discover that the actual cause of the flat was on the other side of the tire.

Pinch flats are sometimes secondary to punctures, and can be deceiving.

That tube was the stock one that came with the bike.

I agree and now have two Schwalbé Marathons supremes.
They are heavier as you say but the rolling resistance is even better thwn on the marathon plus.