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What are the names for the most common ways to get a flat tyre on a bicycle?

I'm very familiar with a "pinch flat", but I recently put too much pressure in a damaged tyre (whose steel braid was bent out of shape). The result was a loud "gunshot" sound -- an explosion of the tube through the bead/side of the tyre that irreparably destroyed both the tube and the tyre. I don't know the common name for this type of flat.

I'm sure there are also many other types of flats. I'd like to learn the names of these other types of flat tyres -- which would be the first step to learning their causes and prevention.

What are the names of types of flat tyres that are common on bicycles?

3 Answers 3

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Blowout is where the tyre failed at holding pressure, and the tube was left unsupported. These holes are often missing small parts of tube, and could have radial tears going outwards. Often sudden, violent, and loud. Sometimes linked to a sudden rim failure, and can also happen when the rim tape has moved or failed and these are on the "inside face" of the tube. Can be patched fine if you have large patches.
This matches your description.

Burp Unique to tubeless, where the bead seal fails momentarily and a partial loss of air, but the gap closes up. Often happens because a corner or a rock/pothole, with already low-pressure tyres.

Failed patch An existing tube patch fails and air leaks out. Often take a while to go flat, and annoyingly-hard to find because the patch may hold 5 PSI of air fine when off the rim, but leaks more at full pressure.

Abrasion A tube may wear through and develop thin spots if it rubs on something inside a tyre, resulting in the loss of air. Sand can cause this, as can tyre liners. This can also happen when a spare tube lives in your bag for a long time.

Heat By itself its hard to get a fully-inflated tyre to a temperature where it will pop, but heat will increase tyre pressure. I've got rim brakes and a long descent can heat the rim to the point I can't touch it, and I flatted near the bottom of the hill. Correlation is not causation, but heat is a contributing factor.

Old Age/Perishing A tube will eventually split - its just what they do. The butyl rubber gets weaker with age and parts, letting the air out. Often worse at folds in a tube, so yes tubes do go bad in storage. Folds can also happen when installing a too-long or wide tube in a smaller tyre.

Snake bite has been mentioned in other answers.

Plain old punctures can occur from road debris like wires or glass, screws or nails. Natural items like thorns and sticks are able to puncture tyres and tubes too.

Vandalism A particularly unpleasant cause for a flat. I remember school bikesheds where 20 bikes in a row all had flat rear tyres one afternoon. Clearly the work of someone with a knife or sharp spike.

Most of these are patchable given time and effort. I personally don't patch on the roadside; instead I fit a replacement tube and patch the dead one at home/work where I have tools and a large track pump.

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    Excellent, comprehensive answer :) but surprising that the word "pinch" doesn't appear anywhere in your answer. Feb 21 at 23:52
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    I think another useful addition would be valve-related failures. Feb 22 at 0:01
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    A less obvious form of vandalism - on Presta valves you can unscrew the locknut and let the tyre down with no tools, or using the dust cap to hold the pin in. On Schrader valves you can put a bit of grit inside the dust cap and put it back or for the same effect (or, I'm told, a lentil works well, particularly on oversized motor vehicles)
    – Chris H
    Feb 22 at 12:53
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    I’ve had ParkTool GP2 pre-glued patches fail in heat.
    – Michael
    Feb 22 at 14:02
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    If a flat has two commonly-used names, I think it would be good to update the answer to include both names. That will make the top answer more useful to people, which is the goal of SE. Feb 22 at 14:02
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There aren't necessarily standard terms for every scenario.

A pinch flat, for other readers' reference, is when you hit the tire hard, and the rim slices holes in the tube. There are two linear holes, kind of like a snake bite. Tubulars can also pinch flat if hit hard enough.

A flat, if the cause is not otherwise specified, would probably be understood as an event that probably resulted from a puncture. For interest, "not otherwise specified" (NOS) can be used as an abbreviation in some medical settings, e.g. the diagnosis of depression NOS.

The OP's situation is a bit of an edge case. I would probably say that it was a blowout. However, most people may picture something like a tubeless tire blowoff, where your tubeless tire is mated to a rim whose effective rim diameter is a bit too small (or some other parameter isn't consistent with the current tubeless standard), and the tire comes off the rim. Or they might think that the tube exploded due to a damaged sidewall.

A sidewall cut is another way to refer to the last scenario if the tire got cut - e.g. from hitting the sidewall against a rock, or from your friend riding into a glass bottle which then broke and skidded into your path, cutting both the tire and the rim sidewall - yes this happened to me. The solution to this is don't hit glass bottles, rocks, or debris that could damage the sidewall.

In some off-road settings, your tire might burp. I don't know what the state of tubeless cyclocross tires is now, but earlier on this was not an uncommon problem even with pressures in the recommended range. Or if your pressure got too low, then cornering might cause a burp on a gravel or MTB tire. The solution to this bit is run appropriate pressure, and be thankful for the current tubeless standard.

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  • I have definitely had a blowout due to failure of the tyre at the bead, twice in fact, but one was due to overpressure from a stuck gauge. I've also had the tube bulging out of a sidewall cut, but let air out in time
    – Chris H
    Feb 22 at 8:04
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Valve related flats.
Valve tears out of the tube.
This can happen when your rim has rough edges around the valve hole, when you are not careful placing the tube on the rim and have to repeatedly adjust the tube position (and do not do that careful enough) or when the tube just has a weak spot at the valve.

Valve valures.
In some cases the inside parts of a valve can come separated from the outside of a valve.
For Schrader valves (also known as car valves) you can buy a tool with which you can unscrew the inner part and tighten if unscrewed by whatever reason.

Presta valves need to be closed after pumping which can be a reason for air leak.

In Dunlop valves there is a ring on the outside of the valve holding the inside of the valve in place and the most common flat with those valves seemed to be a loose ring. Old Dunlop valves have a bit of rubber tubing which can deteriorate and has to be replaced after a while, modern Dunlop valves use a rubber ring for sealing and fail much less.

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  • I am not familiar with the insides of Presta valves, please edit in if there are known problems there. Or of course other valve related flats.
    – Willeke
    Feb 24 at 8:47

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