Exploding ebike tire?

E-HP

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I went on a short errand on my ebike around noon. The bike ran well. A few hours later, while sitting at my desk, I heard and felt a big boom. It was loud and I could swear I felt the house shake a little. My wife came running downstairs and we were certain that something had crashed in our house. I went out an inspected the perimeter and found nothing. The we checked all the rooms to see if something big like a bookcase had fallen over. Nothing.

That's when I went to the garage to ckeck. What I found was that my rear (plus sized 24x3.0) tire tube had exploded. The tire was completely flat and almost coming off the rim. The tire had been at max pressure of 35psi, but that doesn't seem like enough to cause the type of explosion that we felt in the house. Very weird.

The funny thing is, I had just decided to scrap that tire because it's way to noisy on pavement, so I was going to save it for rides where I might be going on soft soil or sand, but not for ever day. I was just clicking the order button when the explosion happened, so maybe the tire knew it's days were numbered. Anyone ever had this happen or that can offer an explanation on why it exploded with seemingly so much force?
 
One time I was pumping up a tire to about 75 psi and the rim was so old and worn out (that bike had probably 20,000 miles on that rim over 20 years time) that the RIM let go and the whole tube and rim caused an explosion that was loud enough that my hearing had a ring for an hour.

Another factor is having a mismatch between tire and rim as far as size.

Some rims run a little smaller in diameter and that can allow the bead to slip out.

And sometimes it's just a weak tire with a bead too loose.
 
SafeDiscDancing said:
One time I was pumping up a tire to about 75 psi and the rim was so old and worn out (that bike had probably 20,000 miles on that rim over 20 years time) that the RIM let go and the whole tube and rim caused an explosion that was loud enough that my hearing had a ring for an hour.

Another factor is having a mismatch between tire and rim as far as size.

Some rims run a little smaller in diameter and that can allow the bead to slip out.

And sometimes it's just a weak tire with a bead too loose.

I'll do a full post-mortem in the next couple of days, but it seems odd for the bead to break loose while the bike is sitting in the garage, vs while riding, but maybe I'll find some clues. I'm expecting the tube to be toast based on how it exploded, so I've already ordered a replacement. Maybe I got something like a pinch flat when I was riding, and/or the tube worked it's way in between the rim and tire. I didn't hit any big bumps, and the rim tape is new. :cry:

I remember when I was a kid, seeing/hearing a car tire blowout (when cars had tubes). That was a big deal, and that was only 32 psi, so it might just be the air volume involved that creates that bigger pressure wave even if the tire pressure is low.

One last thought. When I was out riding, I did three 0-20 mph full throttle runs, so the tire was under a lot of stress and flexing, with the tire was peeling out on dry pavement. Maybe that did something, although the tube itself seemed to stay put, since the valve stem looked normal. But the tire could have slipped or spun on the rim maybe when it hooked up. Sort of a burn out from the inside. I noticed the tire doesn't seem to have a wire bead and went on pretty easy. The new tires will be 24 x 2.8 and wire bead.
 
All of these were years ago, but two times this happened to me, it was the valve stem. For one I'd actually seen the stem's "aneurism" swollen at it's base (presumably also inside the tire, eventually cutting it at the rim valve hole, since that's wehre the rupture was). I don't remember the specifics of the other failure.

The other time I think it burst along one of the seam lines of the tube itself.


I dont' count the time Hachi was eating the tire and wheel and it blew up in her mouth. ;) (which did not deter her from crushing the rim and thoroughly destroying the wheel).
 
amberwolf said:
I dont' count the time Hachi was eating the tire and wheel and it blew up in her mouth. ;) (which did not deter her from crushing the rim and thoroughly destroying the wheel).

Ever eat a tire? Tastes like chicken :lol:
 
Hachi preferred metal and wood over food for her first couple of years or so. :roll: Somewhere in my threads there are pictures of her with shiny metalized teeth from chewing on aluminum things (cranks, wheels, deskchair bases etc). There's also pics of her with her mother Nana eating small trees she pulled out of the ground completely including roots).

I think at least one of the exploding tubes I had is documented in the DayGlo Avenger thread; it might be in the CrazyBike2 thread.
 
A neighbor was killed by the explosion of a farm tractor tire when I was a kid. I was just outside the garage playing with the dog when it happened. Freaking thunder I will remember all my life. A giant cloud of dust and debris blew off the garage door. I fell on my back, shocked with buzzing ears and bleeding nose. My grandfather took me home before I could look inside.
 
MadRhino said:
A neighbor was killed by the explosion of a farm tractor tire when I was a kid. I was just outside the garage playing with the dog when it happened. Freaking thunder I will remember all my life. A giant cloud of dust and debris blew off the garage door. I fell on my back, shocked with buzzing ears and bleeding nose. My grandfather took me home before I could look inside.

We played with a couple of tractor tire tubes when I was a kid. Probably could have gotten killed riding inside of one, rolling down the hill, but we'd do it over and over. Lay it on it's side and it's like a trampoline. Maybe it's the fact that it's encased in the tire that makes even those low pressures deadly. Grandpa made the right call. There's already enough there to make a lasting impression for a kid, no sense adding trauma.
 
I've experienced a few times tire/tube exploding off the rim. Both were after I had inflated the tire to near max. recommended inflation level, on a hot summer day. Getting ready for a ride. Tire was getting full noonday sun, and !BLAM! Loud and percussive, as you say. Everybody hit the deck! lol

Learned my lessons. Don't inflate tire to near max. when going from cool out into the sunny hot day. Especially with older tires.
 
Definitely strange! Just be thankful you weren’t riding the bike when this happen, especially going around a turn!

Do you have some pics? I’m trying to wrap my head around of where the explosion happened. Maybe there was a weak part in the rubber of the tire or something and it blew out.
 
E-HP said:
MadRhino said:
A neighbor was killed by the explosion of a farm tractor tire when I was a kid. I was just outside the garage playing with the dog when it happened. Freaking thunder I will remember all my life. A giant cloud of dust and debris blew off the garage door. I fell on my back, shocked with buzzing ears and bleeding nose. My grandfather took me home before I could look inside.

We played with a couple of tractor tire tubes when I was a kid. Probably could have gotten killed riding inside of one, rolling down the hill, but we'd do it over and over. Lay it on it's side and it's like a trampoline. Maybe it's the fact that it's encased in the tire that makes even those low pressures deadly. Grandpa made the right call. There's already enough there to make a lasting impression for a kid, no sense adding trauma.

All I know is the tire had 100 lbs of calcium salt inside, that is/was common practice as far as I know. I never changed a tractor tire in my life, always gave this job to professionals. Of course, tubes alone are not dangerous. They blow like a balloon and fly away, if they ever do. Most of the time they just leak and deflate.

I found a vid about the danger of tractor tires:

[youtube]uQbKCd3ezrA[/youtube]
 
In the old days there were multi piece semi rims called split rims that were so called outlawed decades ago 6:26 explains the design https://youtu.be/BuFaNv9y29c?t=25 you can also get regular rims that lock the bead for 4x4's which are not d.o.t. rated. I have had one tube pop inside the house while replacing tube and the bicycles tire bead was not set so the tube found the opening and proceeded to pop the tube as it was hidden on the other side after that is when I started to always make sure the bead is set while airing up.
 
Good find MadRhino... Best work safety accident info since I read about bench grinding wheels being covered in metal which can cause them to explode into a worker at 5000rpm... They are one of the most fatal workshop equipments.

If it exploded at rest, i'd say it's not possible: must have been a mouse, they love rubbery things.

I had a tyre burst while hillclimbing, going 800km through France, and another on a hot day in a car park.
 
zzoing said:
If it exploded at rest, i'd say it's not possible: must have been a mouse, they love rubbery things.

The tire must taste like cheese for those mice to gnaw through it in an hour LOL :lol:

I'll be taking the wheel off today, and will report the findings of the autopsy.
 
I'm going to call this a catastrophic failure, and not tube related. At least I know it was wire beaded. Not done inspecting, but I can see the wire bead is rusty, so not sure if that contributed or not, yet. Still need to remove the tire to looks for other signs of how the rupture started, but here's how it ended. Sort of explains why it was so loud:
Cat Failure.jpg

I thought I was going to just swap the tube and start testing my temp sensor. I have two off road, super knobby tires so I could mount one of those (I bought them as an option for trail rides), but I have better tires for my normal riding arriving tomorrow, so I may wait. I was right at the 35psi max, but maybe it was more after my ride after the tire heated up a bit. :shock:
 
Based on that photo, my early failure analysis from afar says tire defect. For the wire beads to come out of the tire casing so easily at 35 PSI there had to be a pre-weakness there. That wire doesn't come out of there that easily, especially several at once like that.
 
Strange the way your tire broke I buy and find a lot of used tires you sure it was seated properly?
 
The tire was perfect when it arrived, and I was thinking it looked better than any tire I've gotten that was shipped to me. It hadn't been folded, the rubber was supple, and no signs of anything wrong, until this. I actually had reseated the tire last week to make sure it was uniformly seated, used a little soapy water so it would seat smoothly, and let it dry for a couple of days. Two days before I rode it up to 45mph before shutting it down, so luckily this didn't happen at speed. I may find out more when I take it off the rim, but too lazy to do that until tomorrow when I change it out for a new tire and tube.
 
The metal bead broke.

That's not supposed to ever happen so this was clearly defective.

Usually a blowout is a failure of the tire casing so this is a rare event.

I'd say replace the tire and move forward assuming this was the odd defect.

Unless you start hearing this defect is all over the place. When a manufacturing process screws up you see it in massive numbers of defects. You should search and see if others are experiencing this.

But again... it's probably a rare event.

Maybe try a different brand?
 
E-HP said:
The tire was perfect when it arrived, and I was thinking it looked better than any tire I've gotten that was shipped to me. It hadn't been folded, the rubber was supple, and no signs of anything wrong, until this.
Look at how this is actually quite interesting. The outer characteristics all looked stellar yet the bead wires were rusted. At least in the photo it appears to have major pitting. Also it's rare to see the wires like that without at least chunks here and there of stubbornly attached rubber (the 2 or 3 courses closest to the rim are bare and exposed).

Either they used rusted wire to manufacture the tire or the tire had less than average vulcanizing around the bead wires and was exposed to heavy rust-inducing conditions during its short life. I have seen rusty wire in otherwise intact tires before but they were really old.
 
calab said:
In the old days there were multi piece semi rims called split rims that were so called outlawed decades ago 6:26 explains the design https://youtu.be/BuFaNv9y29c?t=25 you can also get regular rims that lock the bead for 4x4's which are not d.o.t. rated. I have had one tube pop inside the house while replacing tube and the bicycles tire bead was not set so the tube found the opening and proceeded to pop the tube as it was hidden on the other side after that is when I started to always make sure the bead is set while airing up.
When I was in the Air Farce we had steel cages to put those things in when they required service. Was not aware that they had outlawed them.
 
Old schoolers also used chains which is what handy people do when taking out vehicle suspension coil springs. Has anyone burst a tire instantly when hit an rock, edge or curb.

LewTwo said:
calab said:
In the old days there were multi piece semi rims called split rims that were so called outlawed decades ago 6:26 explains the design https://youtu.be/BuFaNv9y29c?t=25 you can also get regular rims that lock the bead for 4x4's which are not d.o.t. rated. I have had one tube pop inside the house while replacing tube and the bicycles tire bead was not set so the tube found the opening and proceeded to pop the tube as it was hidden on the other side after that is when I started to always make sure the bead is set while airing up.
When I was in the Air Farce we had steel cages to put those things in when they required service. Was not aware that they had outlawed them.
 
Final analysis is a clearly defective tire. The discoloration from the rusting wire bead of the tire was showing about 20% around the circumference of that side of the tire. Over that portion, you could see that the wire bead hadn't been embedded in the rubber, but only had a very thin layer of fabric casing covering it (red arrow), and in some places the wire was exposed (blue arrow). The thin layer of fabric casing wasn't enough to keep the bead in place with any sort of pressure applied, and certainly not 35 psi, so the wire ripped away from the tire. The tube squeezed out of the opening and ruptured. You can see the rust discoloration on the tube from it squeezing past the exposed wire bead.

Autopsy.jpg
 
That damage is characteristic of what occurs when the tire scrapes over the edge of the rim and blows off. It could have been there before your incident, but wasn't necessarily.
 
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