lurker

I finally convinced my wife that she needed to learn how to fix a flat. So, she picked up a thorn on one of her rides (the thorn stayed in so the leak was very slow and we didn't notice it until we were home).

Anyway, she goes about changing the tube under my watchful eye. We even use a brand new tube. Everything goes just fine and we set the bike back on its stand. Then, about 10 minutes later --- bam. We look around and find the cause of the loud bang was that the freshly changed tire is now flat.

I pulled the tube, and attached the image of what I found. (Hope this works)

The split in the tube is about 6" (15 cm) long. It is on the valve side of the tube and goes along the seam except where it goes around the valve stem.

The tube was pumped up to the recomended tire pressure. There were no thorns or anything on the inside of the wheel. I can't imagine the tube was pinched by the stem.

Could the tube have been defective? Has anyone else had a defective tube? How common are defective tubes?

The wheel is a 700x23. On the tube, it says it is a 700x19/23C. However, on the box it says 700x18/20C. LBS said tube would be fine. Is the tube too small?

roadfix

Dang!.....your file is larger than your blowout. It took a couple minutes to load.
You pinched the tube when you installed the tire. Always check the tire bead before you start pumping to full pressure.

dexmax

I agree, I think it is a pinch..

What I usually do when changing tubes is inflate the tire to about 10-15psi then check the bead. then I deflate it if there are problems...

Anyway, It is ok to use 700x20 on a 700x23 tire..

Grampy™

Use talc/foot/goldbond powder on tube and inside of tire.


Oh yeah....... and take smaller pictures. j/k

aerobat

I think I recognize those fingerprints!

ngateguy

And I thought it was just my computer, yep from personal experiance that is a pinched tube

BikerRyan

Sometimes the tube will get seated underneath the bead of the tire (in between tire bead and rim bed) near the valve in the tube because the tube increases in thickness there. After installing the tube and before inflating go 'round the tire and check to make sure that the tube is inside the body of the tire and not underneath the edge of it anywhere. At the stem it helps to push on the stem to tuck that thick place in the tube up into the body of the tire. Then inflate, checking at half pressure to make sure all is well. Your tube was under the edge of the tire and it finally launched the tire over the rim sidewall 10 minutes after the change and exploded. It happens.

-Ryan

Prosody

Hey, at least you weren't still on the road when that thing blew, but that ought to underscore the importance of taking a little extra time to make sure the tube and tire are sitting right.

lurker

Thanks all. Haven't seen the result of a pinch flat before and was really surprised at how much of the tube was blown out.

I'll also promise to reduce the resolution of my camera before posting more pics. Yes, you can do a pretty good job reducing image size with a jpeg (the image was only 55K), but it is a pain with the picture width/height.

Greg

I have a friend that ruined an entire wash load of his wifes clothes just so she'd never ask him to do laundry again. It looks like your wife took my friend's lead.

I've actually done this, as quoted above, the clincher wasn't quite clinched.

Ajay213

A simple solution, buy sew-ups!

Andrew
Hey! Somebody had to say it!