Repairing A Flat Inner Tube - MINSK Repair Manual

Repairing a Flat Inner Tube
There are so many mechanics in Vietnam that flat tyres are normally not a
problem once you have paid VND50,000 for the service of getting them fixed.
However, once you are off deep in the mountains then it is very possible that
there will be no one to help you. Therefor, when on a mission into the wilderness,
you must take a pump, a puncture repair kit and a set of three tyre removing tools.
Remember that you do not need to remove the wheel from the bike to get to the
inner tube, so repairing a flat tyre by yourself is no great drama.
You can make life easier by replacing your old inner tubes with new ones
before you head out. Also ensure that there is a protective rubber loop wrapped
around the wheel rim to stop the spokes from rubbing against the inner tube.
Without one of these on each wheel you will have flats all the time.
If you notice your tyre is flat or is getting flat then the first thing to check is
whether the valve is faulty. In this way you save yourself from opening up the tyre
when all you needed to do was test the valve. Wipe some spit on the valve and see
if a bubble forms. If you are no where near a mechanic then let the air out and use
the top end of a black plastic valve cap to tighten the valve device inside. The cap
can be used like a screwdriver. If the valve still leaks after you pump the tyre back
up again then cover the valve with the black plastic cap and hope that it is tight
enough to limit the air leakage. At the first sign of a mechanic get the valve
replaced. Luckily the valve is standard for all inner-tubes regardless of the bike so
most guys will have one.
When you get a puncture, the first thing you will notice is a wobbling or a
bumping sensation coming from the wheels. Immediately look ahead for a large
rock, ditch or road sign that can be used to prop the bike up. If you do not have a
centre stand then place a large enough rock under the engine near the kick stand so
that the wheel with the flat tyre is above the ground. Sometimes you can use the
cement kilometre stones or posts on the side of the road. If not, just lie it down on
the ground. Then feel around the outside of the tyre slowly and carefully with your
hands and try to spot the protruding thorn or nail. If you find it then pull it out and
remember its position with respect to the valve. Ninety per cent of the time you
can find the nail.
Then remove all the remaining air and loosen the tyre from the rim by hitting
and pushing it. This is often difficult as hot weather can fuse the tyre to the rim. If
you don't do this then removing the tyre will be all but impossible.
Once the tyre is loosened from both sides of the rim, use the tyre
removing tools to lever the edge of the tyre on one side over the metal
rim of the wheel in the same way as fixing the wheel of your bicycle
when you were a kid. You must have three of these tools to do this.
Once you have done this, undo the nut around the valve and pull
the inner-tube completely from out of inside the tyre. Pump it up a bit,
wet it where you estimate the hole to be and look for bubbles to
confirm the exact spot. Stick a piece of grass in the hole so you do not
©Digby Greenhalgh 2000
Minsk Repair Manual
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