Seijun

Since I have started keeping track, my back tire has been going flat every other week. 4 flats in 2 months. There were more before that but I didn't write them down. I am 170lbs riding on a 2010 Kona Smoke with Continental Contact II tires. These tires are less than 2 years old. I only ride about 8 miles per week, and 1/2 to 2/3 of that time is spent on a smoothly paved bike path. The remainder is spent riding in bike lanes.

On every flat I go to my LBS to get the tube replaced. I like to support the local business, and I trust them more than I do myself. The repair guy can never find anything wrong other than the obvious, a hole in the tube. He runs a cloth around and around inside the tire and the rim and it never snags on anything. Is my tire just a dud? Am I that unlucky? Do I have an enemy I don't know about?

Juan Foote

It may not seem obvious to all.

Align your valve stem with the label on your tire and install that way on the rim. Next time(s) you have the hole in tube you will know specifically where the hole was "caused" and can also track if it's the same place every time. If it is there is either something small in the tire itself which is not obvious without weight, or something like a spoke poking, etc. If in different places each time it could just be a fluke along the route.

3alarmer 

...there is a phenomenon known as "Michelin wires" where steel belted radial tires on cars shed very fine short pieces of steel wire and they often end up in the bike lane. I have picked up a couple in my life, and they are very difficult to find in the bike tire. Sometimes they only appear when the tire is pressurized, because they ride within the tire.

You can also end up with something under your rim tape, like small aluminum shavings from when the rim was originally drilled in manufacturing. Those, too, only appear under pressure.

Your best bet is to do as recommended above, then check the spot that seems to be doing this on your wheel or tire.

I confess I once threw away a tire that flatted three or four times, when I couldn't find the problem. It was cheaper and easier to buy a new tire than to keep replacing/patching tubes. And I'm not even a Millennial.

JoeTBM 

I use a carpenters crayon and mark the tire where the valve stem is and direction of travel before I remove it from the rim, then I mark the tube with direction of travel. Blow the tube up after removal to locate the hole and then line up the tire and very carefully examine the inside and outside in that area for a splinter of glass or steel or even a thorn embedded in the tire. Sometime I have to turn the tire inside out to see it.

Last ride 76 

Are you sure your rim tape is undamaged? When you inflate the tire it pushes the rim tape down a bit into the spoke holes. Easy to check if the puncture in the tube is on the inside circumference rather than the side or outer part of the tube... I'm sure your mechanic checked, but...
Eric

ramzilla

You have to learn how to replace your own tubes if you want to be a serious cyclist. It's not complicated as long as you have the proper tools. And, I would recommend installing heavy duty "thorn proof" tires and reducing the tire pressure a little. Try installing some Michelin Pro-Tek or Continental Gator tires. I used to get flats constantly at my place in Florida until I converted all the bikes over to heavy duty tubes & tires.

AnkleWork

Enemies and guessing aside, your "repair guy" has failed to fulfill the one central essential step to flat repair. Avoiding that essential step wastes all other time/effort/money spent on the repair. I won't bore everyone here with a repeat of the widely published and proven method and philosophy for flat repair, as another repeat will just make people even more resistant to it.

Your repair guy is happy to continue selling tubes+installation, or is incompetent, or both. Maybe find a different one or perform the simple repair yourself. Good luck.

DiabloScott

Forensic possibilities:
1. Just dumb luck. Nothing much you can do.
2. Something in tire. If you can't find it, maybe swap front and rear tires to see if your problem follows the tire to the front.
3. Something in rim. Usually this would be a rim tape problem or a sharp burr in the aluminum. A close visual inspection and tactile inspection of the whole inside surface should find it.
4. Problem with mounting. Pinched tube under the bead, very unlikely your mechanic would make this mistake even once, let alone multiple times. Also this problem usually presents itself in an obvious way.

fietsbob

Super thick rubber Heavy Duty inner tubes is my go to, for reliability...


inflate and immerse the tube in water, watch for bubbles..

Note where they are..









....

canklecat

Just another possibility to check...

That Kona probably has the original Rigida Cyber 10 rims. Looks like a decent single wall rim, but probably has the same problem I've noticed with many low priced rims for budget bikes (including my Globe Carmel): the spoke nipple holes had burrs from drilling without finishing up with deburring.

With the usual soft rubber bad rim strips, those burrs can poke through and puncture tubes from the inside. If you get another flat, check the location of the puncture. If it's on the inside/valve side, that's usually due to three problems:

• Burrs in spoke nipple holes poking through soft rubber band rim strips.
• Some other sharp pokey stuff embedded in the rim strip or tape. Try some fresh rim strips or tape.
• The tube extruded under pressure into the spoke nipple holes. Eventually the puckered spots will split at the tips, usually with a slow leak.

If you notice any puckering at regular intervals on the inside/valve side of the tube, each puckered spot corresponding with the rim holes, there's the problem. Replace the rubber band rim strips with Velox or other cloth tape. It provides better support. Be careful the cloth tape doesn't cover the sidewalls of the rim -- it might interfere with seating the bead. I use cloth tape a little narrower than the rim internal width, just wide enough to cover the spoke nipple holes.

To deburr the holes, if you have a moto tool and bits, try those carefully. But I just burnish the holes with a large Phillips head screwdriver, twisting it carefully to flatten out burrs. Often this will dislodge tiny bits of metal, so sweep off the deburred rims thoroughly.

ridingfool

don't think it is the cause but maybe you are getting pinch flats. From tires being under inflated but you would now right away because if you get one u lose all air in less then a min. Also when u check the tube u will see 2 holes often called snake eyes.so always try and keep tires inflated at a high psi as not to get those flats
also at least for me it helps alot I use Conti all season tires maybe one flat every 3000 miles or so

Rick

After you are through with all the other suggestions. Put the largest tube the tire can handle in. The one size fits most concept with bicycle tubs has caused me problems so I put larger volume tubes in.

wingless

My tire was going flat too frequently.

The interior was always inspected for problems, with none found.

The tire and the rim tape were replaced and the problem abated.

pdlamb

I didn't see any mention in the thread so far, so...

OP, you are pumping the tire up regularly, right? Like before every ride? How fast does it flat? It's normal for a bike tire to lose air, and if it's flat after 3-4 days, that's a slow leak but not abnormal. Pump and ride!

grall1126

Get on YouTube and watch some videos, u can do it, air pressure or spokes causing the problem. However, place another tire on the rim, gator tires are the best

Moe Zhoost

Let us know what you did to resolve (once you have, of course). My money is on a wire whisker embedded in the tire. A bit more info on what the puncture looked like as well as it's orientation on the tube would be helpful.

davidad

I have had wire inside the tire that did not show until the tire was inflated and ridden on. Usually the wire flats go down slowly. I forum one by inflating the tire to over 130PSI and submerged it the bathtub looking for bubbles.

Le Mechanic

Blindly throwing new tubes into a setup with repeated flat tires without knowing what's causing the puncture will result in continued flat tires. I made a video a while back with the most common causes. I've seen lots of causes from working as a bike mechanic at my day job for many, many years.

Kapusta

Are these punctures or pinch flats?

As others have suggested, so if it keeps happening in the same location on the tire.