Patching a tyre from the inside.

[Globalti]

Does anybody else do this? I inspect my tyres regularly (they are expected to carry me at speed down hills so it's the least I can do for them) and occasionally find small cuts, sometimes deep enough to have affected the carcass. A while ago I experimented with latex inners but I soon discovered that latex being so thin and flexible, it will find the smallest imperfection in the tyre and herniate through it like a teenager blowing bubble gum. Butyl, even lightweight butyl is stiffer so it "bridges" small holes.

So on a couple of occasions I've found puncture holes where the actual thread of the carcass has been damaged and is showing signs of tearing apart at the hole. The tyre is still fine at 100 or 110 psi but I want to take the strain off the torn threads so I glue in a patch from the inside, which bridges the hole. I can't see any reason why this shouldn't work in prolonging the life of an otherwise good tyre, after all if it's accepted practice in the motor trade where tyres reach much higher temperatures and are subject to much greater loads, I don't see why cyclists shouldn't do it.

Tubeless car and motorcycle tyres are repaired with a little hard rubber mushroom, the stem pulled through with a needle and the head glued inside the tyre:

I wouldn't do this with a front tyre; only rear, but so far I've never had a problem. I wonder if a mushroom system like this could work for repairing damaged bike tyres?

 

[jack smith]

The tube will grind on the patch and cut open. Done it a few times when ive been skint and it always ends up wearing a patch shaped hole in the tube

 

[potsy]

Isn't this just a different method of fitting a tyre 'boot'?

 

[Cubist]

I patch holes in tubeless tyres from the inside with vulcanised rubber sheet cut to size, but then there's no inner tube to chafe.

 

[fossyant]

It's a good idea. I'm using a boot on a tiny hole on a new tyre, the hole is tiny, but it could be enough for the tube to bubble through.

 

[ianrauk]

Have used patches on the inner side of tyres when they have been slightly compromised with no problems.

 

[Globalti]

How do you think a smaller version of the car mushroom could work with bike tyres? The car repair process is that you ream out the hole with a very fast-rotating needle file, which finishes it smoothly and creates space for the stem to pass through the wire threads. Then you thoroughly clean and roughen the inside around the new hole with another fast moving grinding tool before applying glue, then removing the annular cover from inside the patch, pulling the stalk through and then pressing the mushroom hard with a small roller to stick it in. You wouldn't need to do this last bit with a tubed tyre. This would save a tyre that has been gashed by a small spike of glass for example.