How much longer will this tire hold air?

[Roland]

I noticed this on my ride yesterday, and made it home without getting a flat. I'm curious to know how much longer I could ride it before it pops.

[Lister Farrar]

Those aren't Sigourney Weaver tires are they? Are you sure it's not an alien?

With one of these, weeks or months. I've used them on cuts as bad as that for quite a while. Eventually they break up because they don't have the bias plys of fibres to allow flex.

http://www.parktool.com/products/detail ... &item=TB-2

This guy claims you can repair with a section of tubular casing. Haven't tried it yet, but plan to with other frustratingly new, cut tires.

http://groups.google.ca/group/rec.bicyc ... 051eba09ff

With a casing cut, even if it isn't large enough to let the tube burst
out, will nibble at the tube at the cut and cause a leak. Such a cut
as you describe needs structural help and that requires a fabric inlay
commonly known as a boot. These used to be offered for car tires
tubeless tires were not yet invented. The feature of a boot is that
it must flex with the casing and have enough strength to not slip out
of place.

The following item from the FAQ explains how to do this for a tubular
tire (one with the tube sewn into the hose-like casing) but the method
is the same. I carry a rectangular piece of thin tire casing for that
purpose. Because I don't consider this a long term repair for a
clincher, I don't glue it in and finish the ride.
----------------------------------------------------------------------
Casing Repair
Repairing tubular tires requires latex emulsion. You can get it from
carpet layers, who usually have it in bulk. You must have a container
and beg for a serving. If you are repairing a tubular you probably
ride them, and therefore, will have dead ones lying around. The best
tubulars generally furnish the best repair material.

Most cuts of more than a few cords, like a glass cut, require a
structural boot. With thin latex tubes, uncovered casing cuts will
soon nibble through the tube and cause another flat. For boot
material, pull the tread off a silk sprint tire, unstitch it and cut
off the bead at the edge of the fold. Now you have a long ribbon of
fine boot material. Cut off a 10cm long piece and trim it to a width
that just fits inside the casing of the tire to be booted from inside
edge of the bead (the folded part) to the other edge.

The boot must be trimmed using a razor blade to a thin feathered edge
so that the tube is not exposed to a step at the boot's edge,
otherwise this will wear pinholes in a thin latex tube. Apply latex
to the cleaner side of the boot and the area inside the tire,
preferably so the boot cords are 90 degrees from the facing tire
cords.

Insert the boot and press it into place, preferably in the natural
curve of the tire. This makes the the boot the principal structural
support when the tire is again inflated, after the boot cures. If the
casing is flat when the boot is glued, it will stretch the casing more
than the boot upon inflation. After the boot dries, and this goes
rapidly, sew the tire.
----------------------------------------------------------------------

Jobst Brandt
jobst.bra...@stanfordalumni.org

When I do, and If it works, I'll be glad to share pieces of tubular tire casing as boots.

[wonger]

I put a piece of duct tape on one of those about three months ago (on the inside!) and it's still going...

[JohnT]

I hope you're kidding Lister. I'm all for holding on to old stuff - my 9-speed Ultegra is 10 years old. But that tire ain't repairable. I'd give it 10 more minutes Roland.

JT

[JohnT]

Anyone with duct tape, glue, fishing line, etc. holding their bike together should identify themselves with a white patch, or better yet, a skull and cross-bones patch. Or maybe we should have an A+, A, B and cross-your-fingers ride.

JT

[EricS]

The park tool boots are great.

Earlier this week my 12 year old daughter crashed on the observatory hill (going uphill, she's fine) and another girl rode over her rear wheel. This caused a split in the tire just like Roland's. She used a granola bar wrapper as a boot, and it held for about a week before we got around to changing the tire.

As an experiment, I suggest Roland carries a spare tire with him, and rides at the back of all group rides until that baby blows.

[Lister Farrar]

Anyone with duct tape, glue, fishing line, etc. holding their bike together should identify themselves with a white patch, or better yet, a skull and cross-bones patch. Or maybe we should have an A+, A, B and cross-your-fingers ride.

JT

I will as soon as anyone with carbon forks does. Funny how there's a site for busted carbon, http://www.bustedcarbon.com/ but none I could find in 10 minutes of googling "bicycle tire tragedies", "exploding bicycle tire boots", etc. One of our club members has successfully sued for a carbon fork failing and putting it's owner on his face.
(For the record, I don't think carbon forks are especially dangerous, if inspected carefully, but there's some suggestion they are worse than patched tires.)

[Lister Farrar]

This guy claims you can repair with a section of tubular casing. Haven't tried it yet, but plan to with other frustratingly new, cut tires.

http://groups.google.ca/group/rec.bicyc ... 051eba09ff

With a casing cut, even if it isn't large enough to let the tube burst
out, will nibble at the tube at the cut and cause a leak. Such a cut
as you describe needs structural help and that requires a fabric inlay
commonly known as a boot. These used to be offered for car tires
tubeless tires were not yet invented. The feature of a boot is that
it must flex with the casing and have enough strength to not slip out
of place.

The following item from the FAQ explains how to do this for a tubular
tire (one with the tube sewn into the hose-like casing) but the method
is the same. I carry a rectangular piece of thin tire casing for that
purpose. Because I don't consider this a long term repair for a
clincher, I don't glue it in and finish the ride.
----------------------------------------------------------------------
Casing Repair
Repairing tubular tires requires latex emulsion. You can get it from
carpet layers, who usually have it in bulk. You must have a container
and beg for a serving. If you are repairing a tubular you probably
ride them, and therefore, will have dead ones lying around. The best
tubulars generally furnish the best repair material.

Most cuts of more than a few cords, like a glass cut, require a
structural boot. With thin latex tubes, uncovered casing cuts will
soon nibble through the tube and cause another flat. For boot
material, pull the tread off a silk sprint tire, unstitch it and cut
off the bead at the edge of the fold. Now you have a long ribbon of
fine boot material. Cut off a 10cm long piece and trim it to a width
that just fits inside the casing of the tire to be booted from inside
edge of the bead (the folded part) to the other edge.

The boot must be trimmed using a razor blade to a thin feathered edge
so that the tube is not exposed to a step at the boot's edge,
otherwise this will wear pinholes in a thin latex tube. Apply latex
to the cleaner side of the boot and the area inside the tire,
preferably so the boot cords are 90 degrees from the facing tire
cords.

Insert the boot and press it into place, preferably in the natural
curve of the tire. This makes the the boot the principal structural
support when the tire is again inflated, after the boot cures. If the
casing is flat when the boot is glued, it will stretch the casing more
than the boot upon inflation. After the boot dries, and this goes
rapidly, sew the tire.
----------------------------------------------------------------------

Jobst Brandt
jobst.bra...@stanfordalumni.org

When I do, and If it works, I'll be glad to share pieces of tubular tire casing as boots.

FYI, I patched a newish CST tire in the fall with a boot (section of casing) from an old tubular. Been riding it all fall. The sidewall cut was about 5mm, bulging badly. Boot is unnoticeable (ie no bump), and the bulge dissappeared.

Sorry, John, I should have warned you a skull and cross bones on my fender. Will try to find one.

If anyone has newish tires in that state, I can show you what I did, give you a boot, or take them off your hands.

[Kevin F]

Hi Lister,

I'll take a boot! I have 2-3 mm cut in my one ride old $75 conti gp 4000s that didn't play nice with a tire patch, duct tape or electrical tape on the inside. For the record ... I only inflated it and left it over night to find it popped out or bulged to the point I deemed unsafe to ride. then I borrowed a tire from my Dad's bike ... He had a wee accident when his carbon fork failed..... He wasn't using the tire for a while

Kevin