Patching a tyre

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Samuel D
Posts: 2752
Joined: 8 Mar 2015, 11:05pm
Location: Paris

Patching a tyre

Postby Samuel D » 14 Aug 2019, 11:49am

I have a Specialized Turbo Cotton ‘open tubular’ clincher tyre with a cut in the tread. The cut isn’t large, opening to about 1.5 mm at 90 PSI, but that’s enough for a latex tube to start bulging into the gap. A butyl tube fares a bit better.

Would a Rema Tip Top patch stick to the inside of the tyre?

If not, any other suggestions for a semi-permanent fix?

9494arnold
Posts: 820
Joined: 21 Jan 2007, 3:13pm

Re: Patching a tyre

Postby 9494arnold » 14 Aug 2019, 12:07pm

Cut a boot out of another tyre (without the wire) and put it under the cut.

reohn2
Posts: 35170
Joined: 26 Jun 2009, 8:21pm

Re: Patching a tyre

Postby reohn2 » 14 Aug 2019, 12:11pm

I reckon a patch of nylon cloth cut from say an old anorak or similar and glued to the inside of the tyre with rubber solution,would sort that problem.
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mattheus
Posts: 566
Joined: 29 Dec 2008, 12:57pm

Re: Patching a tyre

Postby mattheus » 14 Aug 2019, 12:17pm

9494arnold wrote:Cut a boot out of another tyre (without the wire) and put it under the cut.


That's probably the most common approach.

It's quite a common topic. 5 pages here:

viewtopic.php?f=5&t=103308&start=15&hilit=umbrella+patch

rjb
Posts: 3276
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Patching a tyre

Postby rjb » 14 Aug 2019, 12:23pm

I carry a patch of denim recycled from a pair of jeans for this purpose. In the past I used whatever I had to hand. I previously tried Duct tape, old tyre carcass, even toothpaste tube. All worked ok until the tyre needed replacing. I would put the tyre on the back just in case it fails as you stand a better chance of controlling a blow out. :wink:
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

Samuel D
Posts: 2752
Joined: 8 Mar 2015, 11:05pm
Location: Paris

Re: Patching a tyre

Postby Samuel D » 14 Aug 2019, 12:27pm

rjb wrote:I carry a patch of denim recycled from a pair of jeans for this purpose.

Glued in place? If so, with what adhesive?

Tyre boots from old tyres, etc., would not be satisfactory in this light 24 mm tyre. They would inevitably cause a puncture while ruining the feel of the tyre. The bump might not even be safe on descents.

A friend used a Park Tool TB-2 tyre boot to patch a large sidewall gash on a long ride a few weeks ago. The edge of even this thin boot punctured the inner tube three times on the way home.

Mike Sales
Posts: 2817
Joined: 7 Mar 2009, 3:31pm

Re: Patching a tyre

Postby Mike Sales » 14 Aug 2019, 12:48pm

Samuel D wrote:Glued in place? If so, with what adhesive?

Tyre boots from old tyres, etc., would not be satisfactory in this light 24 mm tyre. They would inevitably cause a puncture while ruining the feel of the tyre. The bump might not even be safe on descents.

A friend used a Park Tool TB-2 tyre boot to patch a large sidewall gash on a long ride a few weeks ago. The edge of even this thin boot punctured the inner tube three times on the way home.


I once used a piece of plastic torn from a discarded bottle. It got me home, no glue, no punctures. Repaired at leisure.

rjb
Posts: 3276
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Patching a tyre

Postby rjb » 14 Aug 2019, 1:24pm

Samuel D wrote:
rjb wrote:I carry a patch of denim recycled from a pair of jeans for this purpose.

Glued in place? If so, with what adhesive?


No glue needed the internal pressure from your inner tube keeps it in place. If you use a big patch you can loop it over the inner tube and over the rim so the tyre bead keeps it in place. Then trim off the excess after you put the tyre back on. If you have nothing to hand having had to employ this method out on the road then centrifugal force keeps it away from interference with brake blocks, providing you made your patch a sensible size to start with. :wink:
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

fastpedaller
Posts: 2003
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Patching a tyre

Postby fastpedaller » 14 Aug 2019, 2:21pm

Use a 5 pound note - it will be cheaper than a new tyre :wink:

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NATURAL ANKLING
Posts: 10347
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: Patching a tyre

Postby NATURAL ANKLING » 14 Aug 2019, 2:33pm

Hi,
Small inner tube path is what I normally use.
Old style puncture outfits used to have a piece of canvas.
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mig
Posts: 2013
Joined: 19 Oct 2011, 9:39pm

Re: Patching a tyre

Postby mig » 14 Aug 2019, 2:37pm

umbrella fabric and tube pressure innit?

Jamesh
Posts: 500
Joined: 2 Jan 2017, 5:56pm

Re: Patching a tyre

Postby Jamesh » 14 Aug 2019, 3:14pm

Halfords do a piece of rubber 4x2" which is ideal for such a situation. Cur to size and stick in.

Cheers James

mercalia
Posts: 10777
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Patching a tyre

Postby mercalia » 14 Aug 2019, 6:18pm

well expect bumpty bump due to the bulge?

Valbrona
Posts: 2192
Joined: 7 Feb 2011, 4:49pm

Re: Patching a tyre

Postby Valbrona » 14 Aug 2019, 6:52pm

For Christ's sake ... chuck it away.
I should coco.

Brucey
Posts: 34709
Joined: 4 Jan 2012, 6:25pm

Re: Patching a tyre

Postby Brucey » 14 Aug 2019, 7:17pm

if you are using turbo cottons then you are not going to want to use tractor inner tubes. Very many of the get you home schemes will only work for a short duration and/or with horrible thick inner tubes.

I think there are two reasonable choices here

a) a rubber patch; this will help stop the tube from getting nipped but it won't stop the damage from spreading in the tyre.
b) using a fabric of some kind.

There is nothing to stop you from using fabric and a rubber patch together of course

The reason I like using fabric from an old umbrella is threefold:
1) it seems pretty rotproof
2) it is thin so you can used several layers (cut to different sizes so the edge of the reinforced area is feathered not stepped)
4) the fabric can easily be distorted so the angle between the warp and the weft more closely matches (and is aligned to) the fabric in the tyre.

So for example the fabric can be cut out in a square, but sheared into a diamond shape before it is fitted as a boot. This gives it the best chance of moving with the tyre; other fabrics (esp those which are not properly aligned with the cords in the carcass) cannot move with the rest of the tyre.

IME the most stressed place to get a hole is not in the middle of the tread but slightly off-centre, i.e. so that the damage is at the edge of the contact patch; the tyre's cords see he highest stresses at different times, i.e. there is a high shear stress in one direction, a more balanced stress, and then a high shear stress in the other direction in sequence every time the wheel rolls over the repaired area.

Three or four layers of typical brolly fabric work well. I have used a spray (contact type) adhesive to mount them, and (IME) the most likely outcome is that the layers stick to one another better than they stick to the carcass but that is with a rubberised carcass; your glue/ turbo cottons may be different to that. Larger booted areas can be trapped at one or both edges by the tyre bead and trimmed in situ accordingly.

cheers
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