Tricky tubular puncture (hole at valve, can't find hole)

[fiks]

Hello all,

I wonder if anyone's tried to repair a tubular that's punctured next to the valve? I suppose it would involve sewing around the valve hole, and the tricky part is how to avoid puncturing the inner tube with the needle. One way I think is to use a very long thread and keep the stitching very loose as you're sewing, so that you can keep the casing open and see where the needle goes. And then pull it tight afterwards.

Another problem is when you can't find the hole. Probably because the hole is very small and/or the the tub casing is not airtight, so when you put the tub under water, loads of bubbles comes out from several places.

I found this:
http://forums.roadbikereview.com/cycloc ... 93230.html

which shows one way to deal with it. They've unstitched around the valve hole and "rotate" the inner tube around inside the casing, so the whole inner can be exposed whilst it's still inside.

 

[foz]

you could always try caffelatex or similar

 

[cchris2lou]

try injecting some latex first , inflate and give it a good shake .
doesnt always work but when it does save a lot of time .

 

[fiks]

Re:

I should have mentioned I'm talking about about a proper repair, ie patching the inner tube. I am not going to squirt some nasty gunk inside my nice tubs!

 

[t47b]

Re:

Have you read good old Sheldon...

http://sheldonbrown.com/brandt/tubular-repair.html

He recommends using a triangular needle ( I then had to google what that was )

 

[bugloss]

The hole may not be at the valve, as sometimes its the easiest place for the air to run too when you pump it up when it's not on the rim.

Before you undo it put 140psi in it and stick it under water, this may make the air come out of the puncture hole in the casing rather than have it travel down inside the case to the valve hole.

Before someone suggests it's going to explode, it won't so don't worry and pump it up hard.

 

[fiks]

Re:

On one tub, there is a hole in the middle of the tread right at where the valve is. And that is where bubbles are coming out and not anywhere else so my guess is that's the puncture hole.

On another tub, there is a gap between the valve and the casing so bubbles are coming out of there.

Both are Vittoria CX.

 

[mattr]

If the puncture is next to the valve, the tube might be unrepairable anyway........

Might be time to get a new tube in there.

 

[bugloss]

Re:

Just a thought, have you got the valve screwed on tight ?

It sounds like you found the hole in one, the other may be a bit more difficult to find. Vittorias are a bit tricky to open up as the tape that covers the thread is quite thin and stuck on well.

I ride on Pave Evo CG tubs and I run them with 100ml of Continental latex in them, as there is a lot of flint on the roads here , but I ride on clinchers when I'm in the UK because the roads are so crappy.

The latex won't damage your inner tubes as it remains liquid, but it gums up the valves a bit.

How many miles have they done?