Tyre patch/boot

[hubner]

To continue the thread on cuts in a tyre:
https://yacf.co.uk/forum/index.php?topic=102049.0

Last week I had a rear puncture caused by a big nail that went straight in at 90 degrees to the tyre, nail was about 1.5-2mm and about 50mm long. I think it was flipped up by the front wheel  to the exact orientation so that when the rear tyre hit it, it went straight in. When I pulled out the nail, the tyre deflated instantly.

I think if I rode over a nail and tried to make it puncture my rear tyre, the chances of doing it would be one in a thousand tries. Anyhow, at least I could replace the tube straightway without having to look for the cause of puncture. for the rest of the journey (about 5 miles), I didn't pump the tyre back to full pressure to reduce the chances of the hole getting bigger.

This left a 2-3mm "hole"


on the inside, one thread was cut, the ply under the tread prob had more, the dark line is where the cords have been pushed apart by the nail.


The tyre is a Vittoria Open Corsa which I bought in 2004; when I got round to using it a month or two ago, I was surprised to see a date of 1997 stamped on the inside!


To make the patch or "boot", I cut the patch from a lightweigh racing tyre, ideally a lightweight tub or "open tubular" where the tread is a separate rubber strip that is glued onto the casing, because you can peel the tread off. In fact I should make one from my old Vittoria Open Corsa tyres, actually I've already got one cut up but I couldn't find it so had to use an old damaged tub instead:



Dated 1995!


I wanted to save the latex inner tube and it took a long time to cut open all the stitching:



section of tub


top is view of the casing with the tread peeled off, bottm is the underside


Next I use rubber solution to stick the patch. I've used Copydex before and that seems to work also. I also feathered the edges of the patch, and hold the tyre in a U shape, ie the shape when it's on the rim, when I stick the patch on because the tyre is very supple and tends to flatten out. Patch thickness is 0.7mm.


The tyre pumped up showing the hole in the tread, Ideally should be filled with something.
And finally a pic of the label.

[Brucey]

I used to use boots cut from tubs but in recent times I have taken to booting tyres with fabric cut from (of all things) discarded umbrellas, which I think is a better solution.

This fabric is vey thin indeed, so you can use two or three layers which are cut slightly different in size so that the edge of the repair is feathered automatically.

It is also possible to shear a patch cut as a square so that it becomes diamond-shaped instead; this sets the plies at an angle that can be made to match the tyre carcass. [Tyre carcasses usually have the plies set at about 70 degrees to one another.]

The fabric is pretty rotproof and (as an experiment) I have successfully used it to repair a hole ~1/4" diameter in a tyre sidewall.

At present I keep my emergency toolkit wrapped in a piece of this fabric.  Should the need arise, I shall cut a boot from the fabric (using half a Stanley knife blade I keep in the kit) and be on my way!

cheers

[hubner]

Good tip about using umbrella fabric, I never would have thought of it! I've always thought anything except thin tyre casing wouldn't be strong enough to stop the inner bursting through the hole/cut and yet at the same supple enough not to affect the ride.

What glue do you use?

With some previous boots, the tyre started to bulge around the patch repair, eventually the tread started to separate from the tyre, I think I made the patch too small for the size of the cut.

[sojournermike]

Lovely post, and Chapeau for riding Open Corsa's before May.

Mike

[mattc]

This left a 2-3mm "hole"


on the inside, one thread was cut, the ply under the tread prob had more, the dark line is where the cords have been pushed apart by the nail.

Good post. But I'm not sure I would have bothered repairing a hole that small - I'd still be riding it today!

Am I mad??

[Cudzoziemiec]

To continue the thread on cuts in a tyre:
https://yacf.co.uk/forum/index.php?topic=102049.0

Last week I had a rear puncture caused by a big nail that went straight in at 90 degrees to the tyre, nail was about 1.5-2mm and about 50mm long. I think it was flipped up by the front wheel  to the exact orientation so that when the rear tyre hit it, it went straight in. When I pulled out the nail, the tyre deflated instantly.

I think if I rode over a nail and tried to make it puncture my rear tyre, the chances of doing it would be one in a thousand tries.

I had a puncture caused in the same way, except by a bolt rather than a nail, about nine years ago. That was on mtb knobblies though.

As for tyre boots, I've carried one around, made from an old tyre tread, ever since I had a blowout caused by a GP 4 Seasons delaminating inside and out a couple of years ago. For the repair then, I used a section of the blown-out inner tube and to my surprise it held not only throughout the rest of the ride (it happened about half way through a 200) but for another month or so until I finally began to think it was a bit silly riding round on a tyre with a delaminated section. It probably would have held for ages if I'd dared.

[Brucey]

Good tip about using umbrella fabric, I never would have thought of it!

I'm kind of kicking myself because I didn't think of it, not for years and years and years...!

I've always thought anything except thin tyre casing wouldn't be strong enough to stop the inner bursting through the hole/cut and yet at the same supple enough not to affect the ride.

seems to work OK so far, but in fairness none of my repairs has done many thousands of miles yet...

What glue do you use?

cheapest/quickest (so far) has been aerosol spray glue from the pound shop; I guess it dries to something like contact adhesive, but stays wet enough for long enough to soak through each layer. Maybe there is something better I've not tried yet.

cheers

[Samuel D]

Fascinating photos! Good job.

I am just wondering if you should have taken more care to align the cords of the tubular patch to the tyre’s cords. Perhaps then the repaired tyre would retain more of its suppleness?

Separately, do you have any idea how much the latex tube weighs? I think tubular latex tubes are even thinner-walled than clincher ones, presumably because they are better protected from spokes holes and the bead-rim interface (into the crease of which my latex tubes have shown signs of stretching).

[Brucey]

latex tubes from old tubs usually weigh about 60-70g. You can use them in HPs (I used to do this) and they feel great,  but they are somewhat delicate, and if you ride all day on them, you can expect to lose up to about 20psi by the time you get home.

cheers

[citoyen]

Fascinating photos! Good job.

+1

I've never considered repairing a tyre this way, but now I've seen this I might try it at some point. Although like mattc, I'm not sure I would have been unduly worried over a hole that size.

I am just wondering if you should have taken more care to align the cords of the tubular patch to the tyre’s cords. Perhaps then the repaired tyre would retain more of its suppleness?

Now that's what I call attention to detail.

[Brucey]

I am just wondering if you should have taken more care to align the cords of the tubular patch to the tyre’s cords. Perhaps then the repaired tyre would retain more of its suppleness?

Now that's what I call attention to detail.

I don't think the error is huge in this case, but it is pretty much essential to at least be mindful of this when installing a 'boot'; if (say) the boot is installed at right angles to the correct orientation, it won't move with the rest of the tyre as it flexes and it will probably come unstuck.

BTW you can test if you have done a decent job or not by riding the bike on a perfectly smooth surface; if the boot is too stiff, or overdone, you will feel a 'bump-bump-bump' from the boot, and if the tyre carcass is stretchy, you may notice that the tyre is slightly narrower/less high where the boot is too.

cheers

[hubner]

Weight of the latex tube is 44g, including the 2 patches! It's 23.5mm wide, measured with it flat.

But I'm not sure I would have bothered repairing a hole that small

I think the hole/cut is worse than what the photo shows. There's a 3-4mm cut in the casing , that's a weak point and the pressure from the inner tube could eventually make the tyre bulge out in that area.

I am just wondering if you should have taken more care to align the cords of the tubular patch to the tyre’s cords. Perhaps then the repaired tyre would retain more of its suppleness?

Now that's what I call attention to detail.

I don't think the error is huge in this case, but it is pretty much essential to at least be mindful of this when installing a 'boot'; if (say) the boot is installed at right angles to the correct orientation, it won't move with the rest of the tyre as it flexes and it will probably come unstuck.

BTW you can test if you have done a decent job or not by riding the bike on a perfectly smooth surface; if the boot is too stiff, or overdone, you will feel a 'bump-bump-bump' from the boot, and if the tyre carcass is stretchy, you may notice that the tyre is slightly narrower/less high where the boot is too.

cheers

I did intend to align the cords but I was concentrating on holding the tyre in the inflated shape and forgot to keep an eye on the exact alignment, next time I'll remember! So far I've tried it in a corridor (maybe 20m long), the floor has floor tiles and is a bit lumpy. I did feel some slight bumps but I don't know that's from the floor or the boot.

[aidan.f]

My get you home boot /patch  is a length of duct tape wound around the  seat-post, could have other uses, mudguard repairs, sticking plaster?

[andyoxon]

The hole on the inside of my Pasela casing looked pretty much like Hubner's...  I found some suitable 'umbrella-like' shiney nylon in the shed, and cut to size then added repair kit rubber glue to casing & nylon, waited, then pressed together.  Seemed to work well - then added a second smaller nylon patch.  Bit of chalk dust rubbed over (after pic).  Anti-tube nibble patch seems secure, & v. smooth.    The cut in outside of tyre glued with contact adhesive seems good still.

P1340667 by ao, on Flickr

[Samuel D]

Weight of the latex tube is 44g, including the 2 patches!

That’s light alright.

Tom Anhalt recently tested a tubeless tyre for rolling resistance with and without a latex tube. He claims they tested the same (in comments somewhere on the SlowTwitch triathlon forum). This suggests latex tubes have a very high restitution of energy when deformed and that your thin tubular tube would not be faster than a regular clincher tube. I suppose it may feel better.

I’d like confirmation of Anhalt’s finding but no-one with a rolling resistance test rig seems to have tested this obvious thing.

[Brucey]

Weight of the latex tube is 44g, including the 2 patches!

That’s light alright.

Tom Anhalt recently tested a tubeless tyre for rolling resistance with and without a latex tube. He claims they tested the same (in comments somewhere on the SlowTwitch triathlon forum). This suggests latex tubes have a very high restitution of energy when deformed and that your thin tubular tube would not be faster than a regular clincher tube.

(my underlining)

not?   Eh?  Or do you mean that the tubeless tyre was tested with a latex tube and then a butyl tube rather than 'no tube'...?

I’d like confirmation of Anhalt’s finding but no-one with a rolling resistance test rig seems to have tested this obvious thing.

That tube quality can make a difference is surely well-known?  For example  IIRC when current road bike tyres were tested last year, they were sorted into two groups, and either fitted with latex tubes or heavier butyl tubes according to their likely use. This made a difference to the power figures (about 3W IIRC) and I would very much have preferred it if they had retested the 'good' tyres (from those originally tested with butyl tubes) with latex tubes instead.

BTW a complication is that with a tube fitted, some of the losses may be because there is relative movement between the tube and the tyre carcass.  This means there will probably be a difference between a talced tube and a 'dry' one, and between a tube that has been installed for a while (they tend to stick regardless after a time) and one that has just been fitted. The result will also vary with the nature of the tyre internal surface, too.

Without understanding how the tests are carried out exactly, it is perhaps difficult to draw exact comparisons.

cheers

[Samuel D]

This suggests latex tubes have a very high restitution of energy when deformed and that your thin tubular tube would not be faster than a regular clincher tube.

(my underlining)

not?   Eh?  Or do you mean that the tubeless tyre was tested with a latex tube and then a butyl tube rather than 'no tube'...?

I meant Tom Anhalt tested a tubeless tyre (I think it was the super-fast Vittoria Corsa Speed Open TLR) with a latex tube and without a tube (tubeless) and saw no difference in rolling resistance. Unfortunately I can’t find his post now; perhaps it was on his Twitter account. I can never find anything again on Twitter.

Someone with a Twitter account could ask him about this and when he’ll update his Crr spreadsheet with the results.

When I said “regular clincher tube” I meant a store-bought latex tube as opposed to one scavenged from a tubular. That wasn’t clear, so you probably thought I meant a butyl tube.

That tube quality can make a difference is surely well-known?

Also well-known or at least frequently tested is the difference in rolling resistance between latex and butyl tubes. But I’m not aware of tests that show the contribution to rolling resistance of a latex tube in a tyre, even though that’s interesting in this new era of tubeless tyres. Tom Anhalt’s test suggests a latex tube may add near-zero rolling resistance to a tyre. In that case, an unusually thin latex tube scavenged from a tubular becomes less interesting.

[Samuel D]

Third paragraph of this post, though it’s not the one I was thinking of. He talked about this in (very) slightly more detail somewhere else.

I’ll wait for the results to show up on his Bike Blather blog or Crr spreadsheet.

[Brucey]

yesterday afternoon I ran over a small stone only to discover that it was actually a piece of jaggy brown glass, about 1/2" long.

"Phfft-fluppa-fluppa-fluppa" went the front wheel.

"Phu** my c***ing luck" (and worse) went the rider.

I'd seen the wretched thing in the road and didn't think to run round it.

D'uh.

The tyre (a Bontrager with Kevlar) had a cut 10mm long in the tread shoulder, 8mm long through the top ply and about 7mm long through to the inside of the tyre.

  The tyre is near the end of its life anyway; it has done many thousands of miles and there is almost no tread left in the centre.

However I decided to brolly-boot it, (three plies, pound shop spray glue, ten minutes effort) and it has gone back on the bike for now. I shall use it for a few weeks and see how I get on. First indications are encouraging; the cut in the tread is hardly open and the tyre has no obvious deformation in the damaged region.

First puncture for about 11 months, that.  [BTW Tubeless would have been of no benefit, I reckon....]

cheers

[hubner]

This another Vittoria Open Corsa I patched more than 10 years ago. I got a puncture with a deep low angle cut after only the first couple of rides, patched it with a bit of tyre casing but have hardly used the tyre since then until a few months ago when I started to use it for my commute (about 2,500 miles).



The patch has held but the bit of the tread that was cut is now like a loose flap. There's a slight bulging around the cut, I think the patch should have bigger.

The tyre in my OP has to be retired after the tread started to peel off which is annoying as the rest of it is still in good condition.