Ken W? writes:
> Using Michelin Pro Race tires while riding got a 1cm cut
> right in the middle of the tread. The cut went clean
> through to the tube. When I got home I tried using some
> super glue to plug the cut. With the cut plugged went out
> riding again. During this ride I developed a slow leak
> emanating from where the cut in the tire is. Needless to
> say the super glue plug didn't hold. Loathing to ditch
> this tire as it doesn't yet have 1000k on it, I proceed to
> patch the cut with an inner tube patch. It seems like it's
> going to work but was wondering if anyone else has had any
> experience doing this.
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.
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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.
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Jobst Brandt
[email protected]
