Lawrenceowns

Hey guys, I recently got a flat on my rear wheel and inspected the tube area and it appeared to be a slow leak (I will link the pictures of the tubes) . I thought it was no big deal so I inspected the crap outta my tires and could not find anything that tell me the cause of the flat. Then I decided to look at my rim, specifically my rim tape it looked perfect as well, no spokes popping up. I put a new continental tube in, rode outside for 20 minutes and got another flat. I inspected the tube and it looked like a good puncture in it around the same area as the first tube. Then again I inspected the wheel and there was nothing to indicate that something had punctured it, I gave it a good 40 minute inspection I kid you not. The pressure on my rear wheel was actually a little low, the recommended was 110 psi but I had it in at 90, I don't know if that could be the cause but if someone could point something out to me that would be great or I might just buy a new tire. He is the link to the pictures of both tubes.

The bottom picture is tube #1 Bike - Album on Imgur

CycleryNorth81

It is the rim tape. Change the rim tape.

Lawrenceowns

It looks far off from that area don't you think? The places where the flats took place when I'm place the tube on the rim don't match up with the messed up tape area. Also the punctured area is not facing the rim tape it is facing almost the top side of the tire.

canklecat

I had four flats last month, three in one weekend. All were difficult to spot.

The first was a tiny metal shard, a little more than 1/8" long and shaped like a tiny fingernail. It had probably been embedded for some time in the tread and took awhile to puncture the tube. Took over an hour to find it. Couldn't feel it through the inside of the tire, running my fingers through. Finally put on some 2x reading glasses, got a flashlight and rotated the tire slowly, until I finally found a tiny glitter. I used a small jeweler's screwdriver blade to gently pry out the shard.

The rim strip was broken at the valve hole but I just patched it with white duct tape. It lasted just fine until I replaced it a few weeks later with a cloth rim strip. The rim strip itself wasn't that critical. The rim shoulders and spoke sets weren't the problem.

All was well for a couple of weeks. Then the highway mowing crews did their last mow of the season before the rains started. This scattered stuff all over the shoulder of the roads I often ride. I can avoid most of the broken glass and metal because it glitters in the sun. But the goat head sticker burrs are hard to see. Two flats in one weekend from those. Each was only 1/8" long, just barely enough to puncture the thin puncture resistant liner on my old Specialized Hemisphere tires. And I dug out at least a dozen other single thorns from the burrs in each tire.

These were tough to find because of the number of burr thorns, and the tube punctures were several inches away from where I'd expected them. So dunking the inflated tube in water to spot the bubbles didn't help - I had to do that with the detached tube to find the punctures.

The fourth flat came from a metal burr in the valve stem hole in the rim itself. It nicked the rubber Schrader valve stem and caused a slow leak. I carefully removed the burrs on both rims.

Got so tired of that mess I replaced everything with puncture resistant self sealing tubes and tires with 5mm thick kevlar shields.

But that may not be an option for you. If you're running lightweight high pressure tires you probably won't want the compromise of puncture resistant tubes and tires. They're heavier and run slower. I'm a slowpoke on a comfy/hybrid bike and "fast" for me is 15 mph on a flat road.

Try this:

• Run your fingers carefully inside the tires, both directions.
• Use reading glasses or a magnifying glass under bright lights while rotating the tire to inspect the entire outer surface. Clean the tire if necessary. Some stuff, like tiny grass burrs, are really hard to spot.
• Mark the tubes/tires/rims with a permanent marker.
• Use the orientation marks to help track down punctures.
• Dunk the inflated tire on the rim to find the bubbles escaping. Mark that area too.
• Keep in mind the bubbles leaking from the tire may not be the precise location of the tube puncture. So repeat the water dunk with the tube inflated with just enough air to take shape and feel a bit resilient. Mark that area too.
• While the rim is bare, check the valve stem holes for burrs. If there are burrs pronounced enough to snag fabric (stocking, cotton wad, etc.), carefully remove the burrs. I used fine jeweler's rounded files, but a fine rounded polishing ball for a Dremel tool would work better. Then burnish the edges with a smooth metal rounded tip - I used the ends of various tools I had around the house. Don't enlarge or reshape the valve stem holes - just carefully remove the burrs. And if you don't feel any burrs, leave it alone. Good rims may not need any attention. Mine are low end aluminum rims.

Retro Grouch 

Buying a new tire is a desperation solution. It's usually possible to figure out and correct the underlying cause:

1. Get into the habit of always installing your tire with the label adjacent to the valve stem. That way you can align your punctured inner tube with the tire and see if you are actually puncturing in the same place.
2. Is the hole on the outside or inside circumference of the tube? Outside = puncture. Inside = rim strip problem.
3. If it's a puncture, look to the area of your tire that corresponds with the hole in your inner tube. I don't live in goat head country so a high percentage of my road punctures are tiny, little, steel belted radial wires. They are easy to overlook. I feel gently around the inside of my tire with my bare fingers but lots of folks prefer to use a cotton ball or something like that. They can also be a ***** to remove but, until you find it and remove it, you are cursed to having repeat punctures.

habilis

The rip in the second picture is huge. Punctures are usually small. Are you sure you aren't pinching or creasing the tube during installation? I use talcum powder or baby powder - it makes installation much easier and safer.

10 Wheels

Most likely an installation problem damaged from a tire lever.

Lawrenceowns

Is there another way to try to detect a hole in a tire itself? Of course there are ways to detect a hole in a inner tube with water, but is there any other way with a tire besides feeling for anything or looking for a puncture?

Wilfred Laurier

Pass a cotton ball over the area you suspect to be causing flats. If there is anything sharp it will snag cotton fibers and indicate the location.

Edit: Also, if you know how the tire was oriented with respect to the rim and tube, you can line up the tube with the tire and the hole in the tube will be in the same place as the hole in the tire (if there is a hole in the tire).

Although the second puncutred tube looks like a huge hole to be cause by a simple piece of debris. It looks more like it was caused by a huge cut in the tire, or by the tube escaping under the bead of the tire - aka installation error. The installation error also agrees with the location on the tube - the area around the valve stem is the most likely place to have the tube trapped between the tire and rim..

CliffordK

I was going to say that is a HUGE hole. Probably from an installation error. If you actually had air in the tire, then maybe the tube pinched between the tire and the rim. Did it blow the bead off of the rim?

How do you install the tubes? Some do the valve first, some do it last. Nonetheless, push the valve in some to get the tube loose near the valve. Always start removal away from the valve.

I always make sure the bead is straight on the rim when installing my tires, also the valve perfectly straight. If it doesn't look perfect when I get about 1/2 pressure in, I let the air out and fix it.

Lawrenceowns

Now that you mention it, the bead on the tire was a bit over the rim towards the valve region of the tire. I always install the valve last, you're probably right it is a huge hole and there is no visible puncture or cut on my tire, it was probably a pinched tube. The first tube was installed before I actually received my bike, but since it is a cheap tube I noticed that all on the circumference of the tube it has some light shredding and is aligned with the area of the slow leak, so that probably caused it. Thanks again.

canklecat

Whoops, I couldn't access the photos hosted on Imgur last night. Looking at the photos now, it definitely looks like a pinched tube. Did that a time or two many years ago when I rode high pressure tubes/tires and needed metal levers to get tires on and off the rims.

I always start with the valve. No idea whether that's considered ideal, although I recently noticed that's what the instructions inside the box for Bontrager tubes recommends as well.

CliffordK

I always start at the valve, and work to the opposite side. But, I have seen people recommend the opposite.

Start opposite the valve. Work to the valve. Then push up on the valve to clear your tube.
Sounds like a neat idea, but after years of working away from the valve, I'm comfortable using that method.