Most Annoying Tube Blow-out Problem

[in.10.city]

I have the most annoying problem with my tube blowing out in the same place over and over again.

This is the rear wheel of the bike I use for my indoor trainer. I have a 700x26 Kenda Kontender tire with AlexRims RP15F rims using 700x18-25. The tire is rated 120 psi. I pump the tire to only 95 psi. The tube blows out about 1 cm from the valve stem on the inside facing the rim and the rip is about 1 cm along the circumference of the tube.

I've had a new rim strip put in and have had the rim and tire replaced. The bike shop hasn't got a clue why. I thought it might be because of the trainer but I never have a chance to even put the wheel back on the bike before it blows again . I also thought that I might be a blazing idiot and could't change a tire correctly but the new wheel was set up by the shop and blew also.

Has anyone had this problem before??

 

[dhk]

I have the most annoying problem with my tube blowing out in the same place over and over again.

This is the rear wheel of the bike I use for my indoor trainer. I have a 700x26 Kenda Kontender tire with AlexRims RP15F rims using 700x18-25. The tire is rated 120 psi. I pump the tire to only 95 psi. The tube blows out about 1 cm from the valve stem on the inside facing the rim and the rip is about 1 cm along the circumference of the tube.

I've had a new rim strip put in and have had the rim and tire replaced. The bike shop hasn't got a clue why. I thought it might be because of the trainer but I never have a chance to even put the wheel back on the bike before it blows again . I also thought that I might be a blazing idiot and could't change a tire correctly but the new wheel was set up by the shop and blew also.

Has anyone had this problem before??

Is the tube big enough for the tire? If the tube says 18-25, it would be too small for a 26 tire.

 

[in.10.city]

Is the tube big enough for the tire? If the tube says 18-25, it would be too small for a 26 tire.

It's a weird size tire I know - 1mm less than a std 700x25. But wouldn't a 28-32 tube be too big??

 

[Hooben]

Sometimes there will be a tiny sharp point right where the valve stem hole is. The sharp point will cause a little rip that will hold air for a little while, them bam it's flat. If you move the stem around too much, then you'll get the flat over, and over. Just feel with your finger around and into the stem hole. Get a small file and smooth all that out. Hope that helps, cause it happened to me.

 

[MattAussie66]

Another problem that I have had in the past is the tyre
slipping around the rim and ripping the valve out. (only on the
back - must be pushing too hard . This didn't happen quickly
usually took a couple of weeks between flats - took a few tubes
before I worked out the tyre bead was too loose - changed
the tyre and all OK.

This was a rather fat michelin (said 23 on the tyre but closer to 28)
maybe similar to your problem?

ttfn
Matthew

 

[in.10.city]

I thought it might be something poking it also, but a different rim does the same thing. And it blows in between the stem and the first spoke (left and right). I'm starting to think that the tire is just a little too big and the tube is just a little too small...

 

[dhk]

I thought it might be something poking it also, but a different rim does the same thing. And it blows in between the stem and the first spoke (left and right). I'm starting to think that the tire is just a little too big and the tube is just a little too small...

That's my guess, based on what you'd already changed, and the fact you said that the tube is splitting open rather than just getting punctured. I'd suspect the tube is too small, poor quality, or old. I'd try a different tube and tire combination.

No telling what the real size of that "26mm" Kontender tire is when it's inflated. Don't know what kind of riding you do, but IMO tires and tubes aren't the place to go cheap on your ride. I'd suggest investing in a good 23 mm tire and a fresh tube of the right size. Also, if you can find Michelin or Conti tubes, believe they are worth an extra dollar or two.

 

[in.10.city]

That's my guess, based on what you'd already changed, and the fact you said that the tube is splitting open rather than just getting punctured. I'd suspect the tube is too small, poor quality, or old. I'd try a different tube and tire combination.

No telling what the real size of that "26mm" Kontender tire is when it's inflated. Don't know what kind of riding you do, but IMO tires and tubes aren't the place to go cheap on your ride. I'd suggest investing in a good 23 mm tire and a fresh tube of the right size. Also, if you can find Michelin or Conti tubes, believe they are worth an extra dollar or two.

I also thought it might be old tubes with hardened rubber but I picked up nice fresh ones and it still happened.

The wheel is on my indoor training bike so I don't want to shell out too much. I'm looking right now to get the Conti Ultra2000 tire in the standard size (700x25) and their tubes... We'll see how that goes...