Why Does My Inner Tube Seem Too Big?

Bikers, do you know that as simple and humble the inner tube of your tire looks, it is one of the most important parts of your bike?

A lot of bikers have expressed their concerns about their inner tube looking too big than normal. Well, here is why.


If you are one of the bikers who are worried about the size of the inner tube in your bicycle then this is for you.

Your inner tubes are bound to look bigger if you install the tubes without inflating them, buy wrong sized tubes or wrong tire sizes.

Basically, if you put the tubes in the tires without any air in it, then it will appear to be too big.

This is because the tube just does not have the shape to sit in a tire yet and if you put it in, well, you will have it drooling out.

What to do? Add little air to the tube to give it shape and try again!

Major reasons why your inner tubes may seem too big (Explained)

For more clarity, we will be discussing the major reasons behind your inner tube looking big.

Before we extensively talk about these reasons, let us highlight them first; Not inflating the tubes, buying a wrong-sized tube, wrong tire size.

Not inflating the tubes

As discussed above, your inner tubes will appear to be bigger than normal if you try to install them in the tires without first inflating them.

Many bike riders like to put the flaccid inner tubes in their tires before they inflate but they end up getting frustrated due to the fact that the inner tube seems like it is bigger than the tire.

Actually, the inner tube is not bigger than the tire, rather it is not in the right shape to fit into any tire (whether bigger tire or smaller tire), because there is not a single whiff of air in it.

So, before you cry foul about your inner tube being bigger than your tires, try to fill it with little air so the inner tube can get in shape before putting it in the tire.

Buying the wrong-sized tubes

As dumb as it might read to you, some bikers actually do not purchase the right inner tubes for their tires.

They either get one that is too big or too small. Most of the time, many of them end up buying one that is bigger than the size of their tires.

Obviously, your inner tube would appear too big because it is in fact, too big! Your inner tube should be the length of the circumference of the mid-height point of your tire.

If you fail to use the correct-sized tubes, particularly bigger ones, you will have a problem with your tires.

Bigger inner tubes tend to fold over themselves because you literally have to stuff them into the tire. This folding can lead to intense rubbing and friction that will damage the tube faster and cause it to fail.

Actually, your inner tubes do not have to be exactly matched with your tires. This is because inner tubes are made of butyl rubber which can stretch.

Your inner tubes can be used for different sizes of tires but it is advised that you match them close to the tires as much as you can. If you get a properly sized inner tube for your tires, it will go a long way in helping you avoid flats.

Wrong Tyre Size

This is similar to buying a wrong-sized inner tube but in this case, the fault is not from you.

Every tire has its size and inner tubes are created to fit into that particular size. However, we have come to notice that the sizing written on many tires is not actually the size at all.

It is unfortunate that some manufacturers give a false disclosure about the width of their tires, and this is sometimes done because they want you to think that their tires are lighter in weight when compared to other competitors.

Another way a tire can be wrongly sized is when, for example, a tire is 25mm.

Truly, the tire may actually be 25mm on the outside but because the tire has chunky treads and really thick sidewalls, the insides of the tires will no longer be 25mm.

The sharing of false information about the actual size of the tires has led many bike owners and riders to purchase wrong-sized tubes thus making them have the dilemma of an excess inner tube.

These three (3) reasons explained above are the major reasons for your inner tube looking like it is too big for your tires.

How do I know what size of inner tube to get?

Now that we know why our inner tube may seem like it is too big for our tires, how then do we know the right inner tube to get? What are the things to look out for?

To correctly ascertain the right size of inner tube to get for your bike, you would need to take a look at the sidewall of your tire.

On the sidewall of your tire, you will find that the manufacturers have printed the exact dimensions of the tire and it is what you need to know the right size of inner tube to get.

Look out for numbers like; 700x23c (if you use a road bike) or 26×1.75 (if you use a mountain bike).

Ideally, you should find these dimensions written on the sidewalls of your tires, but what if you do not find them? How do you still manage to know the right size of inner tubes to get?

The dimensions written (or supposed to be written) on the sidewalls of your tires represent two things; the diameter of your wheels, and the width of your tire.

The first number is the diameter of your wheel and the one that comes after is the width of your tire.

So, when you see something like “26×1.75”, the “26” represents the diameter of your wheels, while the one that comes after the “x”, in this case, “1.75” represents the width of your tires.

Let me explain how this two help in determining the size of inner tubes to get.

Checking the diameter of your wheels

Different types of bikes have different wheel diameters. The wheel diameter for a road bike is different from that of a mountain bike.

The wheel diameter can be 12″ and could also be as high as 29″. Knowing the correct wheel diameter of your bike can help you in choosing the perfect inner tube to get.

Checking the tire width

Just like the wheel diameter, the width of your tires may also vary depending on the type of bicycle.

If you use a road bike, your tires may have a skinny width of 19mm or they could be as huge as 4inch for those using mountain bikes.

Knowing the type of bike you possess and the width of the tires could be the guide you need in buying that perfect-sized inner tube.

After figuring out the correct dimensions either by finding it on the sidewalls of your tire or figuring it out yourself, you can then go ahead to get the inner tube that fits.

It is important for you to know that sometimes you may not get the inner tubes of the exact size or dimension but you will surely find something close.

If you do not get an inner tube of the same dimension, please go for the one that has the same wheel diameter measurements, even if the tire width measurement differs.

This is because inner tubes are made with butyl rubbers and can stretch. Inner tubes basically come in a range of widths. Let us take, for instance, an inner tube with dimensions 26×2.125.

This kind of inner tube only fits a 26-inch wheel diameter tire but it can fit a tire with a width of 1.75 to 2.125 inches.

In some tires, you will find the dimensions written like 700c x 18mm, do not get confused when you see that because some tire dimensions are measured in millimeters.

It is the same thing and the structure (diameter x width) is the same too. The letters after the wheel diameter (mostly a, b, and c) are taken from an old French system that uses letters to measure inner wheel rim diameters.

This French system seems to be similar to what is used to measure bras!

Can I use a smaller inner tube?

You know, it is one thing to have the correct dimensions of your tires and another thing to find inner tubes of the exact same dimensions.

Many bikers, sometimes, find it hard to get inner tubes of the same dimensions so they are confused about if they can use a smaller inner tube.

Yes, you can make use of a smaller tube. Inner tubes are made of butyl rubbers that stretch so you have no worries when you use an inner tube that has a smaller dimension.

However, the only dimension that can be small is the tire width dimension. Do not use an inner tube that has a smaller wheel diameter measurement.

An inner tube that is some millimeters or inches smaller can be used but only if it matches the wheel diameter. An inner tube that measures 700×25 can work perfectly in a 700×32 tire.

Please, apply some discretion when using smaller inner tubes. The 700×25 inner tube that is okay for a 700×32 tire will struggle to work in a 700×45 tire.

Ensure that the dimensions of the tire and the dimensions of the inner tube are not too far apart.

Inner tubes that are too small are easily prone to punctures and tire failures.

How do I know if my bike tubes are too big?

Why Does My Inner Tube Seem Too Big

It can be really frustrating for many bikers when they do not get an inner tube with the exact dimensions they are looking for.

Some of them, oftentimes, opt for inner tubes that have dimensions that are slightly wider than the one they are looking for.

The mistake many of them make, however, is that they end up buying inner tubes that are way too big.

In case you do not know if your bike tube is too big, here are some tips:

  • When there are folds and wrinkles in your tires
  • Heavy tires
  • Pinching between tire and rim
  • Poor handling

When there are folds and wrinkles in your tires

A tire carrying an inner tube that is too big will have folds and wrinkles and such a bike will only give rough rides.

Inner tubes that are too large will double over themselves and such tire would feel like it is uneven when it is being ridden.

A side effect of this is that your tires will get flat easily.

Heavy tires

Another way to know that you are using an inner tube that is too big is how heavy your tires will be.

Wider and bigger inner tubes will retain much more air and thus your bike would require more effort to move.

Pinching between tire and rim

You would know that you have an inner tube that is too big when it gets pinched in between the tire and rim.

This is really bad because of the damage it can cause to the inner tube.

Poor handling

If your bike tube is bigger than it should be, you will experience difficulty in the handling of the bike.

Going by the signs we have mentioned earlier, when your inner tube folds over itself, the ride would feel uneven and handling would be so much more difficult.

Also, having heavy tires would put much stress on your engines and the ride is much more difficult.

If you notice this, then you should check your inner tubes to be sure they are not bigger than normal.

Should a bike tube be loose?

Which works best for your bike – a loose inner tube or a fitted one?

In ideal situations, your inner tube should not be loose. Your inner tube is meant to fit perfectly in your tire.

If you have a wide rim diameter, then you should use a wide inner tube. If you have a narrow rim diameter, then you should use a narrow inner tube.

If your inner tubes were fitted perfectly but later became loose, then understand that there is a problem. Tubes should only expand when you add more air into them.

The best part is that inner tubes are elastic and are made to fit a wide range of tire widths.

This means that you are most likely to get an inner tube that is fitted than one that is loose. If it is loose then it is most likely bad and should be replaced.

In conclusion, we have used this article to highlight why your inner tube may look too big and what to do to make it better. Also, we mentioned tips on how to get the right-sized inner tubes.

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2 thoughts on “Why Does My Inner Tube Seem Too Big?”

  1. I have the correct size tire although beefier due to its puncture resistant: 26″x1.75″ the tube says 26″x1.75 to 2.125″ but it folds over by 3″ in the tire when lightly inflated. It also looks to be able to fit a 27″ or even 28″ rim when lightly inflated (tube is evenly rounded and holds an “o” shape). Could this made in China tube (Bike Shop from Bell Sports sold at Walmart) be mis-sized?

    • I doubt it is mis-sized. However, due to the materials the tube is made from and the conditions under which it’s stored or used, it can have a slight difference in the labeled sized. This difference should be minute and negligible as well.
      You may want to inflate with the lowest psi possible.


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