Tyre repair

[roubaixtuesday]

Punctured a GP5000.

Whatever caused it left a small gash, maybe 5mm long, though only a tiny puncture in the tube (tyre still half pressure overnight).

However, subsequently re-punctured a couple of days later, and it appears the inside of the tyre is sharp enough where punctured to rub a hole in the inner tube over time.

The tyre seems structurally sound, no deformation whatever under pressure at the gash.

Seems a shame to bin it, and it's not a problem I've ever had before.

My inclination is to patch the tyre on the inside with an inner tube patch. Or is that likely also to rub holes in the inner tube? Just sand down the edges perhaps? Or bin it?

Any views, experiences?

 

[wafter]

From the size of the gash there's a chance it'll open up more with use. I've tried sealing them with both vulcanising solution and superglue with no success as they always open up again eventually. It's possible to sew cuts shut to prevent them getting worse, although I can't recommend a suitable needle and thread to achieve this (would like to have a go myself on one of mine).

Patching from the inside with an innertube patch should be fine; be aware that the inside of the tyre will probably have release compound on it, but be mindful if abrading it as you'll potentially expose the ply beneath. I've struggled to patch tyres in a tubeless application this way due to poor adhesion, although if you degrease first it'll probably stick sufficiently to stay in place and prevent damage to the tube.

 

[presta]

Punctured a GP5000.

Whatever caused it left a small gash, maybe 5mm long, though only a tiny puncture in the tube (tyre still half pressure overnight).

However, subsequently re-punctured a couple of days later, and it appears the inside of the tyre is sharp enough where punctured to rub a hole in the inner tube over time.

The tyre seems structurally sound, no deformation whatever under pressure at the gash.

Seems a shame to bin it, and it's not a problem I've ever had before.

My inclination is to patch the tyre on the inside with an inner tube patch. Or is that likely also to rub holes in the inner tube? Just sand down the edges perhaps? Or bin it?

Any views, experiences?

An inner tube patch is no use because it's not the rubber that needs patching, it's the bracing. You need something with tensile strength otherwise there's nothing to stop it stretching just as the tube would if you inflate it whilst it's not constrained by the tyre. I carry a tyre patch from a 1960s car puncture repair kit in my toolkit, but the reason it's still there is that I've never needed to use it. It's like a heavy duty cotton fabric, rubberised on one side, I suppose you could try making one from a suitable bit of fabric. Soak it in rubber solution, leave it to dry, then use it like an ordinary patch.

I've ridden tyres with cuts about that size with no problem, but I've also had others that turn into a rupture within a few hundred miles, too.

 

[13 rider]

I have patched a tubeless tyre before with a regular inner tube patch , never had any issues

 

[oldwheels]

Bin it.
I once had a nightmare journey from Scotch Corner to near Glasgow on a scooter with a similar tyre problem. No spare as the space was used for camping gear and being a Sunday everywhere to buy a new tyre was shut. Tried everything but it still punctured every 10 miles or so.

 

[Ming the Merciless]

Boot the tyre with a 5 euro note. Plasticised card, if thin enough, can work equally well.

 

[presta]

I have patched a tubeless tyre before with a regular inner tube patch , never had any issues

I've ridden tyres with cuts until they wear out without doing anything, but if they are going to go, a tube patch won't have the strength to stop it any more than a tube will have the strength to resist bursting if the tyre splits.

 

[presta]

Boot the tyre with a 5 euro note. Plasticised card, if thin enough, can work equally well.

As a get-you-home measure, but it's not really a repair to last the life of the tyre.

 

[presta]

I carry a tyre patch ... but .... I've never needed to use it.

I did have a tyre split wide open once, but there were just enough threads of bracing left to contain the tube, so I decided to limp to the nearest LBS rather than use up my only patch.

 

[ianrauk]

I usually put a patch on the inside of a tyre if cut is deep enough. The patch won't damage the inner tube.

 

[wonderloaf]

I recently got a similar sized cut in a brand new Schwalbe G-one tyre recently whilst out on only it's second trip, thought there's no way I'm binning a new £35 tyre without at least trying to fix it.
In the end successfully used this tyre repair patch kit:
https://www.ebay.co.uk/itm/133186714396
The patches are very thick so there's virtually no chance of the split opening up and the glue is the vulcanising type which has attached the patch so well to the inside of the tyre I don't think I could remove it now even if I wanted to! I run my tyres tubeless and so far have completed ~1800 miles and no sign of the cut opening up.
The kit has quite a few patches and a large quantity of adhesive so should be good for a few more fixes (if needed)!

 

[Yellow Saddle]

An inner tube patch is no use because it's not the rubber that needs patching, it's the bracing. You need something with tensile strength otherwise there's nothing to stop it stretching just as the tube would if you inflate it whilst it's not constrained by the tyre. I carry a tyre patch from a 1960s car puncture repair kit in my toolkit, but the reason it's still there is that I've never needed to use it. It's like a heavy duty cotton fabric, rubberised on one side, I suppose you could try making one from a suitable bit of fabric. Soak it in rubber solution, leave it to dry, then use it like an ordinary patch.

I've ridden tyres with cuts about that size with no problem, but I've also had others that turn into a rupture within a few hundred miles, too.

Those things you describe are called tyre boots. You can make a very effective one from a plastic milk bottle cut into a nice oval and inserted between the tube and tyre. These new-fangled plastic bank notes also work well in an emergency. They have the added bonus in that you know exactly what your repair costs.

 

[roubaixtuesday]

I'm not worried about the split opening. If it does, I'll bin the tyre. I just want to avoid driving a puncture in another tube.

Sounds like an inner tube patch should do the job.

Thanks all

 

[Cycleops]

Very thin plastic card pre bent to shape.

 

[si_c]

Are you sure there is nothing sharp embedded in the tyre around the cut? If not I'd try taking some very fine sandpaper (240 or higher) and taking the edge off whatever is rough and then apply a boot to the inside.

If that doesn't work I'd just replace the tyre.