# Tubes keep exploding and blowing tyre off rim??



## Macilvennon (Jun 22, 2009)

Hi,
I have recently had a serious problem with my rear wheel. I got a puncture out training at the weekend and changed the tube. Then 3 miles up the road the tube completly exploded. It blew the tyre off the rim. The same thing has happened a total of 5 times over the last 2 days after only a few minutes on the bike. The tube is blowing leaving a 4-5cm tear along the inside of the tube (i.e. next the middle of the rim).

I am running Zipp 404 Aluminium Clinchers, Pro 4 Tyres and Continental Race Light tubes. I am putting around 115 PSI in each time which I have had no problems with for the last 2 months.

I have changed the rim tape, have inspected both the tyre and rim and am still having the same problem. I am at a complete loss to understand what is happening?

If anyone has any suggestions they will be very much appreciated.

Cheers, Bobby.


----------



## simonaway427 (Jul 12, 2010)

Perhaps you've damaged the rim during that first flat - something you're not picking up during your visual inspection.


----------



## icemonkey (Sep 6, 2010)

Bad batch of tubes with weak seams or thin walls?


----------



## pwork (Feb 25, 2009)

Bead failed on the tire? Hard to detect on a folding tire, but mount up another tire and see what happens.


----------



## tlg (May 11, 2011)

Are the failures always at the same location?
Do you mount your tires with the logo aligned with the valve stem? Makes it easy to align the failure with the rim, tube, and tire to inspect for damage. Rather than having to inspect the entire circumference.


----------



## stevesbike (Jun 3, 2002)

do install really carefully, inflating tire to about 20 psi and then pushing tire from rim edge to make sure tube isn't caught under tire anywhere. If that is OK and tire still blows off, try

1. is tire tight fitting on rim? Tires that go on too easily can blow off with high psi.
2. try another tire to see if it stays on.
3. Could be a defect with the tire - I had to return a PRO4 due to a defect (bad seam). Not sure about initial production quality.

I won't ride on a clincher that has this problem - that blowout can lead to a really bad crash descending etc.


----------



## Nielly (Sep 21, 2009)

Do you know what caused the initial flat? Something could be logded in the tire casing? Run your finger carefully along the inside of the tire to make sure nothing is poking through.


----------



## Bridgestone (Sep 6, 2007)

Bad Rim tape, broken bead, pinching tube on install, debris still lodged in tire, take your pick .


----------



## cxwrench (Nov 9, 2004)

basic stuff...you should match up the hole in one of you many blown up tubes to that area of the tire, and you'll find your answer in seconds. if it's the same spot on all of the tubes, obviously there is a hole in the tire. if it's in different areas of the tube every time (this is in relationship to the valve) then they're not being installed correctly, the tube is getting pinched between the rim and the tire then blowing the tire off the rim.


----------



## Hiro11 (Dec 18, 2010)

Sounds like a pinched tube to me.


----------



## Macilvennon (Jun 22, 2009)

Thx for the replies. I have compared the blown tubes and they are in a very similair position...about a third around from the valve, although they are not all in the exact same position.

I had not thought of the tyre bead being defective, but will have a look when I get home today. As for a bad batch of tubes, I will try a brand new michelin tube to see what happens.

The strange thing is that the first flat happened for seemingly no reason at all...the tube just went flat after 2 months of use and the tyre did not blow off the rim.Also no sign of anything sticking through the tyre.

It is definetly not a pinched tube...I have changed the tube 4 times. The tyre is quite tight to get on so I'm pretty sure its not a slack tyre causing the problem.

It's just gona take a bit of trial and error to find out whats going on.

Thanks again for the replies.


----------



## velodog (Sep 26, 2007)

Like others have said, you may be pinching the tube between the tire and rim on install.


----------



## tlg (May 11, 2011)

Macilvennon said:


> The same thing has happened a total of 5 times over the last 2 days...
> 
> I have compared the blown tubes and they are in a very similair position...about a third around from the valve, although they are not all in the exact same position.


Five times in the same area is just too frequent to be a coincedence. Was your tire mounted in the exact same position each time? This could explain the slight variation in position.

I suggest a closer look at the tire. Also try switching your front and rear tires. If it's the tire, then you should start getting flats on your front.
If you still get flats on the rear, it's a rim or installation problem.


----------



## JCavilia (Sep 12, 2005)

Hiro11 said:


> Sounds like a pinched tube to me.


This is right. Mac, you are misinterpreting what is happening. The tube didn't explode and blow the tire off the rim. That can't actually happen. A tube that is confined inside an intact (and properly mounted) tire can't explode (it can get a hole and leak, even rapidly, but it can't really explode). 

The events are actually happening in the reverse order. The tube is first escaping from around the tire bead, either because a part of it got pinched under the bead when you installed the tire, or because yoiur tires fit the rims a little loosely and you're not getting the bead perfectly and uniformly seated around the rim. 

Whichever is the intitial cause, eventually a portion of the tube starts to bulge out between the rim and the tire bead, and its expansion pushes the tire further out so more tube can bulge, and then boom, the overstretched portion of tube explodes.

So the solution is care ful installation. Make sure the tube is entirely inside, inflate partially, check bead seating all around on both sides, inflate more, check again, then finally inflate fully and check again. If something is amiss, deflate, adjust tire placement, and inflate again.


----------



## Macilvennon (Jun 22, 2009)

tlg said:


> Five times in the same area is just too frequent to be a coincedence. Was your tire mounted in the exact same position each time? This could explain the slight variation in position.
> 
> I suggest a closer look at the tire. Also try switching your front and rear tires. If it's the tire, then you should start getting flats on your front.
> If you still get flats on the rear, it's a rim or installation problem.


I have mounted the tyre in more or less the same position each time (Logo aligned with the valve), so that might explain why the location varies very slightly if the tyre has a problem. Thanks for the advice, I'll have a good look at the tyre and try another tyre to see what happens.


----------



## Kontact (Apr 1, 2011)

Sounds like a tube caught under the bead - which is even easier to do with lightweight tubes.

Mount the tire and tube, put a little air in the tube to give it shape, then go around the rim pushing the tire back to look at the rim strip. If you see any tube instead of rim strip, that's what's getting caught and blowing the bead off.

If not, then your bead is somehow very, very damaged, or the rim is damaged.


----------



## gordy748 (Feb 11, 2007)

I once noticed a flat tube on my bike before I went riding, so i changed it. To my annoyance I found I'd pinched the tube so the spare burst as I was inflating it. To my consternation this happened three more times before I'd left the flat (and to my then-girlfriend's hilarity).

What Kontact says about putting on a new tire is right-on. Since that day I've always been exceptionally worried (read, careful) about not pinching the inner tube on its way in.


----------



## cxwrench (Nov 9, 2004)

Macilvennon said:


> The strange thing is that the first flat happened for seemingly no reason at all...the tube just went flat after 2 months of use and the tyre did not blow off the rim.Also no sign of anything sticking through the tyre.
> 
> It is definetly not a pinched tube...I have changed the tube 4 times. The tyre is quite tight to get on so I'm pretty sure its not a slack tyre causing the problem.
> 
> ...


if...
the tires is tight, AND
it's exploding like you say it is, AND
there isn't a hole in the tire that would allow the tube to blow out...

you are pinching the tube during the install. i'm 99% sure of it. i see this ALL the time. there is absolutely no need for 'trial & error'. you flat. you check the tube and diagnose the problem. you fix it, correctly. done.


----------



## velodog (Sep 26, 2007)

Macilvennon said:


> The strange thing is that the first flat happened for seemingly no reason at all...the tube just went flat after 2 months of use and the tyre did not blow off the rim.Also no sign of anything sticking through the tyre.
> 
> It is definetly not a pinched tube...I have changed the tube 4 times. The tyre is quite tight to get on so I'm pretty sure its not a slack tyre causing the problem.


Sounds like the 1st one was a flat and you pinched the tube fighting with that tight tire doing the repairs.


----------



## Gimme Shoulder (Feb 10, 2004)

Double check your rim tape. Sometimes in the process of using tire levers you can scuff the edge of the tape such that a spoke hole becomes partially exposed. You may have a moon shaped piece of spoke hole showing. Had this happen once in my early days - exposed a spoke hole with a tire lever on the first flat - the next 4 flats came free of charge during the next 10 miles before I figured out what happened. Always careful with that now.

Another thought...check that the thickened reinforced base of the valve stem is not preventing proper seating of the tire bead near the valve stem. When the tire is pumped up, this would appear like the tire has a bit of a buldge above the valve stem. You can see it easily if you spin the tire. The way to prevent this is before pumping up the tire, push the valve stem up into the tire past the bead, while pushing the tire down into the bead.

Other than those two suggestions, pinching the tube in the bead somewhere, as others have said.


----------



## cxwrench (Nov 9, 2004)

Gimme Shoulder said:


> Double check your rim tape. Sometimes in the process of using tire levers you can scuff the edge of the tape such that a spoke hole becomes partially exposed. You may have a moon shaped piece of spoke hole showing. Had this happen once in my early days - exposed a spoke hole with a tire lever on the first flat - the next 4 flats came free of charge during the next 10 miles before I figured out what happened. Always careful with that now.
> 
> Another thought...check that the thickened reinforced base of the valve stem is not preventing proper seating of the tire bead near the valve stem. When the tire is pumped up, this would appear like the tire has a bit of a buldge above the valve stem. You can see it easily if you spin the tire. The way to prevent this is before pumping up the tire, push the valve stem up into the tire past the bead, while pushing the tire down into the bead.
> 
> Other than those two suggestions, pinching the tube in the bead somewhere, as others have said.


rim tape problems won't cause the tube to explode and blow the tire off the rim. your second suggestion is what all of us have been saying already...pretty sure that's the OP's problem.


----------



## sadisticnoob (Dec 6, 2009)

sounds like a pinch flat. normally punctures are like as if a needle has poked thru the tube

if the puncture happens on the valve side of the tube it normally means that the spokes has poked your inner tube. 

if it is the upper half means its times to change your tire.


----------



## dcgriz (Feb 13, 2011)

Macilvennon said:


> .......the tube is blowing leaving a 4-5cm tear along the inside of the tube (i.e. next the middle of the rim).
> .


as others have already pointed the tube is getting pinched during installation. The 4-5cm tear is a tale-tell sign of what is happening. It has happened to me as well when I rushed through and apparently caught the tube under the tire bead, the tube exploded and pushed the tire out of the rim when pressure reached 110 psi. I had tried to install the tube by removing only one side of the tire off the rim (which I have repeatedly and successfully done in the past at the side of the road, but this time the tube was somehow caught under the bead).
The way to make sure a pinched tube is avoided is to remove the tire from the wheel, blow a bit of air in the tube to give it shape, put the tube in the tire, take the tire-tube and put the tube stem through the rim, starting from right opposite to the stem install the tire-tube using your fingers to press the beads into the rim, finish at the stem.


----------



## Shiftracer (Jan 18, 2008)

*Another option*

If you continue to have issues, try mounting the tire (or tyre) 180 degrees from your normal install. If it comes off at the same place on the tire, I'd suspect a rare but possible occurence of the Kevlar bead failing. If it comes off at the same place on the rim, I'd suspect rim damage, although that would seemingly be visible upon careful inspection.


----------



## cxwrench (Nov 9, 2004)

sadisticnoob said:


> sounds like a pinch flat. normally punctures are like as if a needle has poked thru the tube
> 
> if the puncture happens on the valve side of the tube it normally means that the spokes has poked your inner tube.
> 
> if it is the upper half means its times to change your tire.


the OP's problem definitely DOESN'T sound like a pinch flat. when the tube 'explodes' and pushes the tire off the rim, it is because the tube is caught between the tire and the rim. this happens because the tube installation was done incorrectly.

'if the puncture happend on the valve side of the tube...' yes, it does mean a spoke has poked the tube, but it has done that because the rim tape is damaged. spokes don't randomly poke out and puncture tubes. 

getting a puncture on the tread side doesn't usually mean you need to 'change' or replace your tire. just replacing the tube is fine, unless the tire is damaged.


----------



## mudge (May 15, 2010)

I'm pretty sure going tubeless will solve everything...


----------



## Shiftracer (Jan 18, 2008)

mudge said:


> I'm pretty sure going tubeless will solve everything...


...and cure the common cold.:thumbsup:


----------



## rearviewmirror (Aug 20, 2008)

I've recently had an issue with this, the seam on the underside of the tube was torn about 4 inches and the tire was blown about 1/8th off the rim. I don't particularly like the anxiety this causes. Both time it happened I heard a "ping" sound the BLAMMMM! I'm hoping it was an isolated incident, I put the new tube in very carefully to ensure there isn't any twists or folds. To be honest, in nearly a decade of road cycling I've never had this happen, it's only happened on the Hed Jet 6's, not sure if because of the wider room there is more room for the tube to get misaligned, or just an anomaly all together.


----------



## RobFL (Apr 22, 2012)

I was sick and tired of getting flats each month. I just recently ordered Mr Tuffy tire liners from Amazon and had my LBS install it and so far so good. Some who have used it said they have not had flats for a very, very long time as a result.


----------



## bmwjoe (Jul 15, 2012)

I think the rim was damaged. Look for any marks or bent spots where you are having issues.

On the other hand, this happens to me every now and then when I don't get the tire onto the rim correctly. the beads must seat in the clinchers.


----------



## twaing (Nov 29, 2011)

Look for rim damage. I had the same problem. Rim had a little concave spot. Blammo


----------



## Zen Cyclery (Mar 10, 2009)

RobFL said:


> I was sick and tired of getting flats each month. I just recently ordered Mr Tuffy tire liners from Amazon and had my LBS install it and so far so good. Some who have used it said they have not had flats for a very, very long time as a result.


The one issue with Tuffys is that they are so darn heavy! Have you tried putting Stans sealant in your tubes? I did it to mine and this is my second flat free season (knock on wood).


----------

