How to Patch a Tube
I’m thoroughly convinced every parent should teach their child how to patch a bike tube shortly after the training wheels come off. It’s simple, it’s fast, and it’s the key to independence on a bike. After all, flat tires don’t understand the concept of bike-shop hours, spotty cell signals or friends with lives that don’t revolve around getting your chain grease all over their car seats. Learn to patch your own tube, and not only do you save money (and waste) on new ones, but you also gain the freedom to take stress-free solo journeys to scenic, untouched wonderlands far from the reaches of society and technology. And who doesn’t want that every once in a while?
To start, lay your wheel out in front of you and remove one side of the tire from the rim, using your hands or a tire lever. Pro-tip: As you’re pulling the punctured tube out, carefully keep it lined up with that tire so when you find where the tube puncture is located, you can search that area of the tire for what caused it. Be careful with the valve when you’re removing the tube from the tire—if you break off the valve or tear a puncture into its neck, you’ll have to replace the tube entirely.
Things you should carry in a small flat-repair bag:
3-4 tire levers
A patch kit with self-adhesive patches or glueable patches, patch glue and a scrap of sandpaper
A small pump (I can’t recommend the Topeak Mini Morph enough)
A backup tube (optional in case the valve is cashed)
Fill the tube with air, and try to locate the source of the puncture. Remember to keep the tube lined up with the tire if you can. Listen closely for hissing air, feel around the tube and even hold your sensitive lower lip close to the tube (this is actually the only way I can find less-obvious punctures) as you search for the source of deflation. If all else fails, put some water on the tube or hold it under water to look for bubbles. Once you’ve found the root of your troubles, use a pen to mark the hole with a big X.
Line your tube up against the tire again and feel around inside and outside the tire for the glass or debris that caused the leak. Sometimes rocks will be embedded in the outside of your tire in a way that makes the problem less apparent from the inside. Pull out your small, nefarious adversary. If you found two small holes close together on the tube—called a “snakebite” or “pinch flat”—the cause of the puncture is just an underinflated tube. Try to never put your tube back in without solving the mystery of what punctured it—chances are, it’ll immediately go flat again.
Now take the sandpaper in the patch kit and scuff up the area on the tube where you drew your X, making sure to cover larger than a patch-sized area centered on the hole. Really rough it up and give it a good talking-to. Once your tube knows its place, spread a very thin layer of glue over the area. Give it a couple minutes to dry, blowing on it if necessary. When the glue looks dry-ish, carefully remove a patch from its foil backing and press it firmly onto the tube. Hold it down for as long as you dare and either peel the clear plastic tab off the top or just leave it on. It won’t hurt anything.
Put your patched tube back in your tire, inflate it slightly and pop the tire back onto the rim, using your hands if you can so the tube doesn’t get pinched. Now inflate your tube fully. Good as new! Back to exploring the untamed countryside.
Want more DIY bike fixes? We've got:
Expert Tips from Bike Mechanic Instructor, Dylan Robbins.
How to Fix Your Squeaky Brakes
How to Tune a Rear Derailleur
How to Measure and Replace Your Chain