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Fixing a flat

This article is about how to fix a puncture on a bicycle tire

  • What tools are needed?

  • A pump.

A puncture repair kit containing:

  • Tyre levers (at least two, preferably three)
  • Rubber patches
  • Rubber vulcanising solution (glue that sticks rubber together)
  • A crayon

You might also need:

  • An ajustable spanner (preferably two) (US: wrench)

How to do it

Step 1. If you have a puncture, first you need to remove the wheel from the frame; on some bikes you need to detach the brakes to do this. If your bike has Quick release wheels[?], the wheel can be removed by loosening and unscrewing the quick-release bolts. If you wheel is attached to the frame by ordinary nuts they will have to be undone with a spanner.

If you have to take off the back wheel it is usually a bit more complicated, because you need to get the wheel past the chain. If your bike has multiple gears Derailleur gears, change into the very top gear to make it easier to get the wheel off past the chain. It is best to put the bike upside down when removing wheels, although it is possible to do it with the bike upright.

Step 2. When you have got the wheel off you need to lever open a gap in the outer tyre and remove the innertube. This is usually quite tricky because it means you have to squeeze the tyre out past the wheel rim, and this needs the tyre levers.

First, push the outer tyre as far in towards the wheel as possible. Do this by squeezing the edges of the tyre inwards and forwards and continue to do this right around the tyre. This is necessary because it reduces the diameter of the tyre and makes it easier to remove.

Then insert a tyre lever between the wheel rim and the tyre, and lever the edge of the tyre up over the rim. The tyre lever usually has a little hook at its non-levering end; use this to hook to a spoke and hold the tyre in place.

Now get another tyre lever and a bit further up the tyre, lever another bit of tyre past the rim. This can sometimes be quite difficult and often requires a lot of force.

After you have a fairly large section of tyre up over the rim, get a third tyre lever and start to lever the rest of the tyre over the rim, working your way around until the whole of one side of the tyre is over the rim.

Now you will be able to remove the innertube: carefully push the tyre valve through the hole in the wheel where it sits and with your fingers (dont use anything sharp) gently ease the innertube out from between the wheel and the outer tyre,

Step 3. Now that you have the innertube out you need to locate the puncture. The usual method of doing this is to pump up the innertube and put your ear to it: if you hear a hissing noise locate it and then use the crayon supplied with your puncture repair kit to mark the location of the puncture. If this dosn't work get a bowl of water and pump up the inner tube. Put it under water and then watch for bubbles, which indicate a puncture.

Step 4. After you have located the puncture, you need to patch it. To do this apply a film (not too thick) of rubber vulcanising solution, supplied with your puncture repair kit, several centimetres around the puncture.

Wait for several minutes until the solution becomes dry and tacky. Now get a patch, peel off the plastic coating on its back, and stick it squarely over the puncture. Hold it down and press it firmly for a minute or so until it is firmly stuck. It is usually a good idea to pump up the inner tube to check that it has stuck properly and seals the puncture.

Step 5. Now you need to get the innertube back into the outer tyre and refit the outer tyre. Before you do this, feel with your fingers the inside edge of the outer tyre to make sure that no sharp objects are still pointing through.

Now carefully with your fingers ease the innertube back into the gap between the wheel rim and the outer tyre, making sure that it is the right way around and isn't twisted. You have to get the tyre valve back into the hole in the wheel where it sits, as well.

Now you need to lever the outer tyre back over the wheel rim with the tyre levers, which is usually easier than getting it off. You usually just need to gradually lever the tyre edge over the rim until the whole tyre is over it. While you are doing this try to make sure you don't get the innertube caught between the outer tyre and the rim.

You then need to reattach the wheel to the frame and make sure it is firmly attached, and pump the wheel up.



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