How to Measure a Motorcycle Tire Size Correctly

A common question among bikers is how to measure a motorcycle tire tire size correctly. You may be tempted to believe that the width of your tires determines the size, but this isn’t true. The height and width of a tire are measured in inches and typically don’t match up with each other when it comes down to measuring them on a bicycle. It’s important for riders to learn how to measure their tire sizes so they can buy compatible parts or change their own tires out if needed.

It’s important to have the right size because if it’s too small, it’ll be difficult for you to ride. If it’s too big, then your bike will wobble and feel unstable. You can use this article to learn how to measure bike tires correctly.

The surprising thing is, many of us ignore the aspect of sizing our motorbike tires. That’s why I crafted this simple but useful piece on how to measure bike tires.

Tips About How to Measure Motorcycle Tire Tires

Why Should You Learn to Measure Your Motorbike Tires?

Allow me to explain – Most of the time, when any need for upgrade or replacement arises, riders are happy with whatever bike tire that will come along or leave it up to the hand of the local bike accessories shop.

However, a smart bike rider might ask himself, “This should probably be an easy task.” In addition to that, if you want to buy the tires online, you should know your requirements like – the size of your bike tire, what type of tire you want to go with tubular tire ? Or you may want to buy a tubeless bike tire or motorbike tire etc. In today’s world, every tire has its size marked outside, but these numbers gradually fades.

Before jumping into measuring, it would be nice to know some basics on tire size & what do the numbers mean, which are printed on tires.

Motorbike Tire Size:

The conventional sizing system was based on the measurement of the diameter. It was not a good quality sizing system. The development of tires & rims, nullified this type of sizing system. Meanwhile, companies developed their sizing structure. This phenomenon made it extraordinarily hard to buy a tire. To solve this problem on sizing, ISO introduced a standardized sizing system.

Explanation of the Numbers:

Almost every tire has the size printed on it. But it can wear off easily. The larger number stands for the tire diameter, while the smaller number tells you the tire width. Usually,these measurements are in inches, but millimeters can also be used.

Additionally, these tires can come with various sizes depending on types. Some common measurement for the diameter is 26, 27, 27.5, 29 (all are in inches), etc. Bicycle wheels can cope up with a range of different widths, so it’s not necessary to match the exact width with the old one during the replacement.

How are Motorcycle Tires Measured: Step by Step

how to measure bike tire size correctly

Method 1: Using the Standard Method

Step 1-keep the Bike in an Upright Position:

Stand your bike upright or lean it against a wall. This position of the bike allows you to measure smoothly. If you are doing it alone, I would recommend you to use a retractable metal tape rather than a plastic tape as it’s stronger and will leave you with a free hand.

Step 2 – Measuring the Diameter:

Put down the tape against the center of the wheel. From there, expand the tape in a straight fashion towards the edge of the outer tire. Now double the length that you have just measured and you have the diameter. Pretty easy, right?

However, in most cases, tire diameters are whole numbers. So, if your measurement emerges to something like 26.8, then take it as 27 inches.

Step 3 – Measuring the Width:

It is easier than measuring the dia. Place the tape on the ground across the tire’s tread going from one side to the other side in a straight direction. The width may vary to a great extent depending on the intended use of the tires. For example, bikes that are made for rough terrain have tires with a wider width, while bikes with tires of narrow width promise a fast & smooth ride.

Step 4 – Incorporating the Measurement:

Generally, the standard procedure is – place the diameter first, then the width. For example, if you find the diameter as 27 inches and the width as 2.4 inches, the printed measurement would be 27 X 2.4.

Method 2: Measuring the Circumference

how to measure bike tire size correctly

This measurement is useful, especially if you need to calibrate your bikes speedometer or GPS. If you buy a new cyclometer or want to calibrate the one you already have, you will need the wheel’s circumference.

You can measure the circumference of a motorbike tire in two ways, it depends on whether you know the dimensions of the diameter or not. As you are smart enough to measure the diameter by now, just multiply the diameter by Pi. As we all know, Pi is equal to 3.14. So, if the diameter is 27 inches, you multiply 27 by 3.14.

In case you don’t know the tire diameter, you can measure the circumference by using a string. At first, evenly wrap a string around the surface of the tire. Where the string returns to its straight point, make a mark or cut the string on the spot. This distance from one end to the marked/cut point – is the circumference of the bike and motorcycle tire. Learn more about motorbike tires.

Method 3: Using the ISO Method

Step 1 – Check the ISO measure system printed on wheels.

The International Organization for Standardization has been an international body that sets out rules and standards. For instance, the ISO system uses millimeters to measure your bike wheel size in order to help you know what will fit on it. If you don’t have a measuring tape with metric units, just be aware there are 25.4 millimeters per inch and use this simple calculation: 1 inch x 25.4 =25 cm so multiply inches by 25cm which equals about 100mm or 1 meter of diameter (length).

  • ISO size is the most convenient option is available at home and will give you accurate measurements while saving time!
  • Tire sizes are listed on the sidewall of a tire by ISO measurements. The size can be checked easily, so you know what’s going to fit your bike best!

Step 2 – Keep the bike on kickstand for start measuring.

The circumference of a bike tire is usually measured in millimeters from the center of the wheel to only the inner edge. Multiply this figure by 2, and you’ll know its diameter! Most adult bikes have tires that measure between 650-700mm round with ISO systems.

Step 3 – Tire width measure in millimeters.

The process is actually quite simple, as long as you remember to do it right. You can use the same technique listed above, across from one side of a tire to another for any bicycle wheel size difference that isn’t too drastic.

Step 4 – List up the width & diameter.

You may be wondering how you are supposed to know the dimensions of a tire when shopping for one. Well, an ISO sizing system is works by listing width first followed by diameter – so 39 x 700 would mean that it has treads measuring 39 millimeters wide with a wheel size of 700mm from outer edge to radius which equals 622 mm on the BSD scale.

To Sum Up

Conclusion paragraph: As you can see, there are a few different ways to measure the size of your bicycle tire. Don’t let this information overwhelm you! For most people, it will be enough to know that they need to determine their wheel size in order to find the right bike tire for their needs.

In fact, measuring a bicycle wheel is part of basic maintenance and should not intimidate or confuse anyone who has ever put air into an inflatable toy before. We would love nothing more than help you to successfully purchase tires for bicycles so you can stay safe on the road.

I hope this article will benefit you while purchasing tires online or offline.

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