DougG

I had a flat out on my trail bike while riding a local packed-limestone rail-trail yesterday. I always try to determine the location and cause of a flat, so I inflated the tube after removing it, quickly found the leak (about a 1/16" slit), and matched the position against the tire circumference.

Try as I could, I could not find any evidence on the outside or inside of the tire to indicate something piercing it. In the past, I've usually been able to find a matching small puncture in the tire, but this time nothing that I could find.

This was on dusty packed limestone and this area does not have any chronic tire-puncturing hazards, so I'm at a loss to determine a cause. My only concern is that I've only had these tires on for a couple of weeks and I'm already nervous that I bought some flat-prone models (Kenda Kross Plus 26x1.95)...

woodway

Could you have pinch-flatted?

BluesDawg

I wouldn't worry. You'll know before too long if you missed something still in the tire that caused the flat. I sure wouldn't fret over the tires possibly being flat prone. Time will tell if they are.

DougG

Thanks for the quick responses.

I doubt it, mainly because I aired it up just before the ride (60psi). OTOH, I do remember hitting a hole or something in the trail shortly before the flat that really gave me a jolt. So I guess it's possible, but there was no snake-bite evidence.

I'm sure there's nothing still in the tire and just hope that nothing gets in there in the future!

bradtx

DougG, I carry a couple of cotton balls to help find debris in the tire. Rub it along the inner surface and it'll snag if anything is still in the tire. It's not too confidence inspiring when I don't find anything and still have X miles to go.

Brad

DougG

Thanks for the tip, Brad. I wasn't as much concerned about something still being there in this case as being curious about not finding any evidence at all of a puncture in the tire itself. But soft rubber is somewhat self-sealing so that a small pin-prick might be even more difficult to find than I expected.

Recycle

Sometimes those things are hard to find, even with the cotton balls. I once 5 flats in 10 days ... all at the rim same location ... Even had two other people looking to find the cause. We finally found a tiny piece of glass imbedded in the rubber such that it was normally completely retracted into the tire. After the 5th flat, it finally worked it's way far enough thru the tire so we could see it and dig it out. Apparently, the only time it poked thru to damage the tube was when I hit a bump.

Another thought is to check the rim tape. Can a spoke be poking thru, or is the tape seated improperly?

rm -rf

Pinch flats are toward the rim side of the tube, not the rubber tire side. Where was yours? A slit does sound like a pinch flat.

PatW

I have had that one happen too. It was a sliver of glass. When the tire was inflated, the pressure caused the sliver to poke out just a little bit and slowly work a hole in the tube. But when there was no pressure, it withdrew into the almost invisible little slit in the tire. I did find it by examining the spot after reinflating the tire. It took some digging getting it out of the tire.

stapfam

Definitely bought the wrong tubes- Never use anything other than a top end- Schwalbe- or Michelin or Latex.


So why did the OCR I just sold have its first puncture in the rear tyre last week when I bought it in 2006? Repaired the tube and couldn't help noticing it was a "No Name" chinese thing that was very thin.

I get worried If I can't find the cause of the puncture and remove the tyre- Turn it inside out and use a cloth to find any flints or thorns. Surprising how many you find that haven't yet caused a problem.

And a tip I learnt for Puncture location. Put the name of the tyre next to the Valve when you fit it. Then once the hole in the tube is found- you have an indicator as to where to look on the Tyre for the flint/glass/thorn.

roadiespinner

Check the rim strip. Some of the plastic ones get cracks in them then "pinch" the tube, when they flex.

bigbadwullf

If it holds air, who cares? Might be the valve. I have valves go bad more often than a hole in the tube.

gear

Could be a bad tube. Maybe the item fell out when you took out the tube or maybe it went inside the tube. I'm supposing if it slid down in the tire you would have found it by holding the wheel upright and seeing if anything was loose inside the tire.

Wogster

Raid the misses makeup cabinet and get a cotton ball, drag the cotton ball along the inside of the tire, all the way around, if there is anything poking through, the cotton will catch on it. Depending on what pierced the tire it could have been a small item that went all the way through the tire, or it could have been something that went through and back out. I've seen flats before where there was no evidence in the tire, sometimes the cut in the rubber will self heal to some degree. If there is nothing poking through, then don't worry about it....

Terex

Turn tire casing inside out, this usually forces imbedded object to protrude from inner surface. Use your finger, or cotton ball then.