How to Patch a Bicycle Tube

by Raymond Parker on April 30, 2011

in Technical

A home recipe for polybutl repair

If you followed my advice on the Fixing a Flat page to save your punctured tubes to patch at home, you might have collected a few. Here’s how to patch them:

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Find the puncture

First, inflate the tubes and examine them for punctures. Hold tubes up to your cheek to see if you can feel air escaping. If you have difficulty, fill a sink or bowl with water and submerse the tube.

That should quickly tell you where any holes are located. Make sure there is only one hole; check the whole tube. If the puncture was caused by a pinch flat, there will usually be two holes (snake bite) close together.

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Circle the spot

Once you’ve located punctures, circle them with a felt marker. It’s easy to loose track of a small hole.

Next, rough up the area to be patched with emory cloth (usually included in a patch kit). Make sure to flatten out mold ridges on the tube, if they intersect the area to be covered by the tube.

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Sand the tube

Remark with your pen if necessary.

Choose an appropriate size patch from the patch kit.

Apply a small amount of glue to the area to be covered by the patch. (Safety: Make sure you have adequate ventilation)

Allow it to dry for a minute.

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Apply glue to tube

Peel the backing from the patch and apply the patch firmly to the tube, taking care to push down the thin, tapered edges.

If any section of the edge has not adhered, add another small spot of glue and work it in, then apply pressure until it sticks.

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Apply patch

Allow the tube to dry for a few minutes, carefully peel the celophane cover from the patch, then inflate to test the bond. It is adviseable to submerse the tube in water again. Careful observation will reveal even the slowest leak—no worries about replacing a tube on the roadside only to have it deflate a short time later!

Remember to replace dust caps (if only to protect tubes fron valve abrasion during storage and transport).

You can now wrap tubes and secure with elastic bands. I recommend storing them in ziplock bags with a puff of talcum powder to keep them from sticking. Be sure to mark the bags with the tube size, particularly if you use different tubes for different size tires.

Wasn’t that easy? Your job is done for another year!

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