How to fix a puncture

Cyclescheme, 20.02.2012

How to fix a puncture

So long as you don't rush it, patching a punctured innertube is easy – and the repair can be permanent.

Before you start, this guide assumes that you already know how to change an innertube. Read that first if you don't. It also assumes that you've found – and if necessary removed from the tyre – whatever it was that caused the puncture. Never fix a puncture before thoroughly checking the tyre.

Puncture kits come in two types: traditional, with glue; and self-adhesive. Self-adhesive patches are quicker and more convenient to use at the roadside (ignore steps 5, 6, and 10 below), whereas patches with glue are more likely to provide a permanent repair.


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Rema Tip Top patches are particularly good, as the design makes it less likely that you'll lift the edge of a stuck-down patch. But any kit can provide an effective repair, so long as the hole is patchable. Some are not: slits longer than 2-3mm grow longer over time and can make a patch ineffective. Be prepared to buy a new innertube in that case.

Generally, repair is straightforward. Here's what to do.

  1. Remove the wheel and innertube, then locate the puncture, as per our guide to changing an innertube.

  2. If you can't find the hole in the tube by sound or feel, there is a last resort for tiny pinhole punctures: immerse the inflated tube in water and watch for bubbles. (Dry it after.)

  3. Once you've found the hole, mark it with a big cross using a ballpoint pen. The cross should be centred on the hole, and should be much bigger than the patch you're about to apply.

  4. Thoroughly roughen the innertube around the hole with the puncture kit's sandpaper or metal scuffer. The area roughened should be bigger than the patch you're applying. Roughening the tube will obliterate the centre of your drawn cross but you'll still be able to see the outer edges – like a gun-sight centred on the hole.

  5. Apply one thin film of vulcanising solution (i.e. glue), spreading it over an area larger than the patch with a dry, clean finger.

  6. Leave it alone for at least five minutes. This is critical. The solution has to dry. If it's wet, it won't work. Go and make a cup of tea while you wait.

  7. Peel off the foil backing and apply the patch, centred over the hole. Press it down firmly all over for a minute or so.

  8. Remove the cellophane or paper backing, taking care not to lift the edges of the patch.

  9. Inflate the tube to check that the patch stretches with it. If it comes off or there's a hole under one edge of the patch, remove it and start again at point 3. This time, roughen the tube more thoroughly and let the vulcanising solution dry more.

  10. To prevent any chance of the innertube sticking to the inside of the tyre, it's helpful to dust the glue around the edge of the patch. Chalk dust or talc is fine. If you have neither, just wait a while before refitting the tube.

Refit the repaired innertube as per our guide, or fold up this innertube and use it as your spare.


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