FIXING A PUNCTURE
Punctures are a fact of cycling life. For the users of inner tubes they’ll require a repair. This is an easy job and one all cyclists need to know how to achieve with the minimum of fuss.
Our guide below shows you what we believe is the best method fix a puncture. We've included a list of the tools and materials that you will need to complete the job and in some cases where you can buy them. If there are others that you prefer then feel free to let everybody know in the comments.
Tools & Materials
1. When the tyre goes down, before you remove it from the rim, check the outside closely for the likely source of the puncture. Sometimes it's blindingly obvious, like a whacking great nail, both other times small pieces of glass or thorns can be harder to spot. Naturally, spotting them with the tube still in place, will give you a guide as to where to look on the tube. If you grab the tube straight out of the tyre without checking, you've no idea where it might be.
2. If you can't see or feel the object from the outsude of the tyre, remove it from the rim and gently feel around the inside of the tyre carcass with your fingertips. Go lightly and slowly, as the protruding item might be sharp enough to cut you.
3. The culprit may be small, but you have to be sure that you have them all out. We've fixed thorn flat before, removed the one that did the damage, but missed another that was partially through, ready to do it's deflating work a mile down the road.
4. When you find the object causing the puncture push it back out of the tyre carcass. Do this from the inside out, never pull objects fully throug the carcass, you're only making a bigger hole in the tyre. Small sharp or pointy items can be pushed back with the end of a multi-tool or whatever 'harder than a finger' bits you have with you.
5. Add some air to the tube. Small punctures will allow the tube to take some air, long enough to pass the tube through your hands and under a moistened lip. You should feel/hear/sense the air escaping.
6. The holes can be hard to see with low air volume, and nearly invisible when the tube is flat. when you've located it, put your finger on it as a marker and keep it there until you can mark the hole properly.
7. You use the yellow crayon to mark the hole. Most patch kits come with a stub of the waxy stuff. It's not ideal as it's reluctance to show in the butyl, can makes accurate location of the hole tricky.
8. Though, if possible, we prefer to mark the position of the hole with a biro. Any colour will do, the ink sticks to, and shows up well, even on black butyl.
9. We draw a circle around the hole, just a bit bigger than the size of the patch to be used. With the hole in the very centre. We then draw a pair of crosshairs centred on the hole with the ends extending outsdie the circle. This allow you to rough the site of the hole, apply vulcanising solution and let it cure, without losing the eact centre location of the hole.
10. Roughen the butyl around the hole with the small piece of sandpaper included in the patch kit. We have in extremis, roughened it using a handy kerbstone. You're only looking to give the surface a 'key', so don't make it a ragged affair.
11. Apply the vulcanising solution. Don't be shy with it and for the sake of avoiding unstuck patch edges, make the glue zone slightly larger than the patch.
12. Let the vulcanising solution cure. This takes around five minutes, check your particular patch kit brand for the exact timing. Don't be tempted to rush it, however far behind the group you might be getting. One fix is quicker than two.
13. When the vulcanising solution has cured, peel the foil backing from the patch, making sure you don't touch the exposed patch surface with your fingers. leave the plastic layer in place to make positioning the patch on the tube easier.
14. Look for your cross hair guide lines and when centred, press the patch firmly into position. If you've got time, we leave it for a further five minutes to let the chemical bond really take effect.
15. Carefully peel the plastic backing from the patch. They often have a pre-scored line in the plastic, so you can flex and split it and peel off from the centre of the patch outwards, to reduce the chance of pulling the edges of the patch up.
16. Take the small cube of French chalk from the patch kit and grate a little onto the repaired area. This is to stop the tacky vulcanised rubber and solution from sticking to the inside face of the tyre carcass.
17. Give the tube some air. Providing you've spotted all the holes, it'll be going up and staying up. Replace the tyre and tube. Inflate to your favoured pressure and enjoy the rest of your ride.