off of the bike. If your bike doesn’t have
quick-release hubs, this means you’ll also
have to carry that size wrench with you to
remove the wheel, which can be heavy and
take more time. If it’s the tire on a bike with
a hub drive, you’ll also likely have to disconnect the quick-disconnect on the wire leading to the hub. Check your owner’s manual
about orientation of connectors, axles, etc.
in this case. There are times it can make a
difference (e.g., a BionX wheel has a slot that
must face straight down when you reinstall
the wheel so the system can calibrate correctly).
FINDING THE LEAK
If you can ;nd the leak, often you’ll be
able to ;nd the thorn or puncture hole. If you
know where the leak is to start, patching
will be easier. If you don’t know where it is,
sometimes you can pump up the tire and
spin it slowly to listen for the leak. If you still
can’t ;nd it, you’ll have to take the tube off,
which means taking the tire off and taking
the tube out.
Once you have the wheel off, fully de;ate
the tire using the valve. Then take the tire
bead off the rim. This can be done with ;ngers, which is safest, but if you need extra
leverage, you can use a tire lever. A set of
tire levers, usually the plastic ones are the-best and lightest, is another thing to consider
carrying with you.
Insert one of the levers under the bead, then
pry it back and hook the other end on a spoke
to hold it in place. Then, put another lever in
a few spokes down the line and pry it back.
Taking care not to nick the tube, slide this lever
around the rim to pull the bead over the rim
all the way around. Then pull the valve out of
the valve opening in the rim. With Schrader
valves, this can be done easily by just pushing
it through. With Presta valves, there’s usually
a nut threaded down on the valve, and you’ll
have to unscrew that and set it aside, then you
can push it through the hole.
Remove the tube and inspect it. If it’s a
really small hole that you can’t see, pump
some air into the tube. A cursory check can
be done running your hand over the tube,
but some leaks are small enough that your
hand may not feel it. Hold the tube up by
your face and hold the tube near your lips
(not touching) and rotate the tube around
until you feel it. Your lips have more nerve
endings than your hands and will feel the air
escaping from the tube easily.
An alternate to that is submerging the
tube, a part at a time, in a sink ;lled with
water. You’ll see the bubbles escaping where
the leak is. You’ll then have to fully dry the
tube before patching it.
Before you do anything else, mark the
hole with a marker or ball-point pen. This will
make ;nding it again much easier, even after
you rough up the surface.
An alternate to the small pump is the CO2
in;ator. You use CO2 cartridges to in;ate
the tube quickly and easily. You will have
to carry extra cartridges too.
Hook the other end on a spoke; that’s
what that little indentation is for.
A set of tire levers is great for times your
;ngers won’t work. This set of plastic
ones weighs almost nothing, and the
two parts ;t together to take up minimal
space in a bag.
If you do get a ;at from a leak
caused by a thorn or similar, try
to ;nd the leak without taking the
wheel off. If you can, pry the bead
off the rim with your ;ngers. You’ll
never nick a tube this way.
Use a second lever to pry another spot a
few spokes away, and then you can pull
the bead off the rim in one motion.
To pry the bead off the rim, insert the
rounded/hooked part of the lever under
the bead and rotate outwards.
When you do ;nd the puncture,
mark it with a ball-point pen or
Sharpie. This will make it easier to
;nd the hole again after the next