Heey

What caused this flat tire? I was riding my bike and the tire felt normal. I locked my bike, when I came back the tire was flat.

Later I opened the tire, expecting to find glass etc, but there was nothing poking through the tire at all. I found was this big hole in the inner tube, what caused it?

The hole was at the side of the inner tube.

The front tire was nearly worn out, it was near the end of its life, I was planning to replace it this summer.

I also had a tire liner in that front wheel. So I wasn't expecting a flat tire at all.

Any questions just ask.

It says I need 10 posts to link a photo, so instead here is a link to the flat, just remove the space in between words post and img in the address:

i.post img.cc/zNQYSSc3/IMG-20240502-073753.jpg

soyabean

The inner tubes inside also do a lot of tearing and pulling.

Take the example of how you can wear pants, and still scrape and sratch your skin to bleed, but show zero tear to the jeans.

Just riding your bike, the inner tube is always being pulled and rubbing within the inside of the tyre.

This hole is far too large to patch.

New inner tubes are not all equal. Some are better than others.

Thicker ones trade off with heavier weight, but may be worth it to some.

Andrew R Stewart 

The image shows what I call a "start burst" hole, a classic unrestrained tube blow out. For some reason the tube was no longer kept inside the rim/tire interior, that bit of tube tried to push it's way out and became so thinned out it burst. I describe it as like a hernia of sorts. The usual reasons are a hole/slit in the tire or the rim is a double wall (box cross section) design and the rim strip didn't fully cover the spoke nipple access holes. This second reason is especially insidious as when the tire goes flat the rim strip can return to its unpressured placement and it will look like the strip is fine. If the strip is made of stretchy rubber this is particularly easy to have happen and why with double walled rims rubber rim strips are to be avoided. A third reason is that the tire's bead didn't stay fully overlapped with the rim's side wall. A bit of the tire crept up and off the rim (poor install or bad fit) until the tube had an escape route and tried to push out. When installing a new tube one has to be careful with initial inflation to not have the second tube suffer the same blow out. Andy

Crankycrank

If you mean by tire liner that it is one of the flat prevention types that fit between the tire and tube then that could be the problem as well as the other causes mentioned. These liners tend to cut the tube after a number of miles. The cutting can be reduced by smoothing down the edges of the ends of the strip as this is usually where the damage happens.I had a hole like that years ago from a flat strip. As mentioned it also looks like a blowout type hole where the tube was pinched by the bead or there was a cut in the tire allowing it to balloon out.

grumpus

Looks like a typical unseated bead blowout - the tyre wasn't fitted straight, the bike was left under hot sun and pressure rose to the point the tube escaped. Tire liners can cause as many problems as they solve - the edges can rub against the tube, particularly at the ends, not necessarily related to this particular problem but something to be aware of.

grumpus

It's a wide tube, it will patch just fine with a large patch as long as it's properly prepared.

Heey

The side wall at one location was frayed, it was like a 1 x 2 cm area where it was just strands of plastic, there was a bit of a small bulge when the tire was inflated, it was still usable and I thought about keeping the tire, but i had 2 spares in my closet unused for years and I decided to use one of those instead, as front tires last for years and years.

here is a link to the pic, just remove the space in between post and img in the address:

i.post img.cc/4s5Zw3wL/IMG-20240502-133958.jpg

I can't say for certain that the inner tube hole was found near that area; after i removed the tire + inner tube from the rim, i kept their positions in front of me as I looked area by area for the hole, after finding no glass near the hole I moved everything around looking for some other kind of damage, but didn't see anything. the position of the bulging sidewall relative to the inner tube hole was not preserved.


I put on a new tire yesterday (26 x 1.5), with a new tube (it was a 26 x 1.75 inner tube, a bit over the stated size, will this be a problem? i had no more thin inner tubes, I ordered some, they are coming in the mail in several days), plus the same tire liner, pumped it up to 50 psi only, due to extra space the tire liner took up.

took it out for a short trip for errands today, the ride felt fine. I originally planned to swap it out with a 26 x 1.5 inner tube when it gets here, but i was thinking i could just save myself 30 minutes and leave everything as it is, why solve a problem when everything is working fine right? your thoughts?

cyccommute 

Photo assist.

Any time a tube bulges out of a tire for any reason, the tire is not usable. It is toast. The tire is a pressure vessel and will hold a significant amount of pressure but it has to be an intact unit. The tube, on the other hand, is not a pressure vessel. It is a balloon and will pop just like any balloon if pressurized past its ability to stretch. An open hole in the tire just allows the tube to stretch enough to go **POP!**

Additional observation, you seem to have a bead problem where your thumb is as well. The hole in the sidewall is likely the cause of your blowout but a bead separated from the casing can also cause blowouts.

Heey

noted, in the future, i will replace any tire that has a lot of sidewall damage.

One point about the bead, i went downstairs and pulled at the plastic, it came off, but the metal part was ok, IMO i would say if the bead was like that it is still usuable:

i.post img.cc/9CV1CXVj/IMG-20240502-141233.jpg


on the flip side, here is the sidewall damage from the other side, the plastic "flap" is covering the damaged strands, i didn't want to post this earlier because i thought it wouldn't be helpful:

i.post img.cc/t945nrYS/IMG-20240502-133825.jpg

I just realized, due to the overlapping beads, it might be hard to tell which bead is which bead for each side, if you all need a new photo i can try for another one.

soyabean

The sacrifice of thin walls and even thin plys is saved weight.

That's why you notice tank tyres like Marathon Plus, the walls are just as strong as the ply.

grumpus

No, it definitely was not still usable - if the carcass is distorted the tyre is garbage, the threads that hold it together are broken, and more will follow. The threads wrap around the steel bead to contain pressure, if some are broken then it's just the rubber holding them together and it's not strong enough, particularly as it's probably cracked or crumbly, damaged by "dry rot".

cyccommute 

More photo assist.

That piece of rubber hanging down used to be wrapped around the wire bead. You may have damaged it when you removed (most likely) or installed (less likely) the tire. Tire levers often tear the rubber coating. If you are too aggressive in your tool usage, you can often tear this rubber. That isn’t an issue, until it is. In your case, it looks like it might be exposing the bead which means that the rubber isn’t going to keep the bead from slipping off.


Here you have completely lost the tire integrity. The casing has separated from the bead and allowed the tube to expand out of the tire. Again, the problem might be with tool usage that was too aggressive. It could also be just a failure of the tire due to quality issues. Either way, the tire is not usable nor can you repair it. Time for a new tire.

Heey

Yes, thank you for the info, I will keep it in my mind for the future, it is not often i replace tires, front tires are especially long wearing.

What do you think of the tread wear (as shown in the last pic with the flap), the tire was a good quality tire, it served me well for so long.

cyccommute 

The tire is hardly worn at all. Kind of unfortunate that it failed, it could have lasted for many, many miles.

RCMoeur 

The tire depicted in the photos is done. Even I as someone who tries to get as many miles as practical out of a bicycle tire would retire that one immediately. I see bead issues and cord separation/delamination, which explains the blowout.

The method I use to keep an end of the tire liner from damaging the tube is to wrap it in a short doubled-over piece of cloth tape (any tape other than cellophane will do in a pinch). I do both ends to be safe.That way the tape absorbs the movement and damage instead of the tube.

grumpus

I've sanded a taper in the overlapping parts and rounded the corners, but if it's TPU you might be able to weld the ends together - making it endless would remove the problem (but make it harder to use the rim strip with different size tyres).

Heey

I replaced the front tire with this tire:

(just remove the space in between words post and img in the address)

i.post img.cc/nF7rNRpF/IMG-20240504-075849.jpg

grumpus

That doesn't look much better than the other one - tyres degrade with time, regardless of how worn the tread is, and this one appears to have some bead damage too.

sweeks

This has not been my experience. I've had no flats from punctures while using liners. Inner tubes are inspected every couple of years, and I've never seen any abrasions or wear in the neighborhood of the liner ends. Possibly this is because these are 20" (406) wheels for some reason I can't fathom.

grumpus

I suspect under-inflation may be a significant factor when tube damage occurs.

sweeks

This makes sense! I tend to keep my tire pressure up, so there's less sliding around inside the tire.