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How To Mess Up A Tube Replacement

Posted: 30 August 2021 Tips & Tricks

A bicycle mechanic at Bio-Mechanics Cycles & Repairs removing a tyre from a wheel

Changing a tube is an essential skill that any bike rider should know. (Yes, even if you run tubeless; the best sealant in the world won't help you if you've slashed a massive hole in your sidewall.)

At its heart, tube replacement is a simple procedure -- here's a refresher -- but there are still quite a few ways that it can go wrong. Here are the most common problems, and how to avoid them in the first place.

Mistake #1: Not checking inside the tyre for protrusions

Getting a flat is annoying, but you know what's even more annoying? Fitting a new tube and then immediately getting another puncture from same thing that caused the first one.

Homer Simpson, about to let rip with the loudest profanity Ned Flanders has ever heard
*insert Homer-swearing-birds-flying-off-church gif*

Sharp objects like glass and thorns can easily disappear inside the tyre tread; they're not immediately obvious on the outside, but are still lurking on the inside, waiting to deflate your dreams like tiny assassins. Thorns also have a tendency to break off, just leaving the tip inside. Thanks, you bastards!

The solution: make sure that there's nothing still stuck in the tyre. After checking the outside for glass, nails, bastard thorns, etc., run your hand around the inside of the tyre to check for any pointy leftovers. (Hot tip: wear a glove for this bit.)

Mistake #2: Not noting the position of the valve

Before you remove the old tube, make a note of where the valve is in relation to the tyre. Now locate the site of the puncture. Once you find the hole, use the valve point as a reference and match the hole up to the puncture point in the tyre. Double-check the area -- inside and out -- to make sure nothing's still stuck in there. (See Mistake #1.)

Mistake #3: Not checking the rim tape

If your puncture is on the inside edge of the tube, the issue will be rim-related. Spoke holes that aren't covered properly can lead to punctures, as can any sharp edges on the rim itself or even on a rim tape or tyre liner; some of them are very abrasive, which your tubes will hate.

The solution: make sure the rim tape is completely covering all of the spoke holes, and check the rim for sharp edges. Pay particular attention to the valve hole; pointy bits here can damage your valve, too. When that happens, all the patches in the world ain't gonna help you.

A bicycle tube which someone has attempted to fix with a bandaid. (Spoiler alert: it didn't work.)

Mistake #4: Not inflating the tube before fitting it

Stuffing a completely flat tube into the tyre is a recipe for disaster. Most likely, it will get caught between the tyre bead and the rim. You'll know it's happened when you are temporarily deafened after your tube explodes upon inflation. Hurray! Not only have you potentially scared yourself to death, you also now have to get another tube.

The solution: give the tube some shape with a bit of air first. (Not fully inflated, unless you're really in the mood for a wrestling match.) With a little bit of air, you'll find it much easier to fit. And far less explode-y.

Mistake #5: Not checking the beads

As with Mistake #4, a tube that's caught in the bead is a shortcut to heart attack city (plus more money to spend). A quick visual check before you attach your pump will ensure that your sanity and eardrums remain intact.

The solution: once the second bead of the tyre is on, start opposite the valve and compress the tyre back from both sides of the rim to make sure there's no bits of tube poking out between the tyre and the rim. Check the whole way around until you get back to the valve, then repeat on the other side.

As a bonus, this step can also help get the final part of the bead over the rim if it's a tight fit. You're welcome.

A bicycle tube twisted inside a tyre
Tube origami: an underrated sport

Mistake #6: Not seating the valve

This is the final important step that many people miss. If you don't do it, and there's excess material caught around the valve hole, guess what happens? Yup, it's another tube explosion. How's your blood pressure? Good?

The solution: after you've checked the beads and are ready to go, push the valve stem up into the tyre and pull it down again. This properly seats the valve. Now you may pump with impunity.

Mistake #7: Not using proper tyre levers

Please do not use random objects, such as screwdrivers or spoons. There's not only a high chance of pinching the tube but also of damaging the rim.

The solution: a set of tyre levers will set you back less than $10. Buy some. Don't be a cheapskate.

A bicycle tube bulging out of a wheel in sections, like a string of black rubber sausages
Run for your lives, children!

Mistake #8: Snapping the valve off with your pump

One drawback of many hand pumps is that you have to hold them very steady while you're inflating your tyre. If you wiggle the pump around, it's very easy to either damage the valve or rip it off completely (if you're more of a Hulk Smash kind of pumper).

The solution: either invest in a hand pump with a flexible hose (we're fans of the Lezyne range for this reason) or learn how to properly brace your grip. Stop that wiggling, mister.

Alec Baldwin, riding a bike and carrying a takeaway coffee, looking suitably annoyed that his front tyre has gone flat
Mr Baldwin regrets

Honourable mentions:

  • Running the new tube at half the recommended PSI, almost guaranteeing another flat.
  • Not waiting for the glue to become touch-dry before sticking on a patch.
  • Sticking patches upon patches upon patches.
  • Trying to change the tube while the wheel's still in the frame. (Yup, really.)

So there you have it. If you're going to spend time and money repairing a flat, make sure you're not wasting your efforts. And if it's all too much? Just bring it in to us and we'll sort it out for you.

In loving memory of tubes lost to improper technique

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