eBike Kit Tyre Sizes | How to measure the 3 tyre sizes

ebike conversion kit wheel sizes

Understanding Tyre Sizes for Ebike Kits: What You Need to Know

If you’re thinking of converting your regular bicycle into an electric bike, one of the first things you’ll need to do is figure out the tyre size. This can be a little confusing, especially if you’re not familiar with bike terminology. In this blog post, we will explain what each tyre’s size means and how it affects your ebike. We’ll also provide some tips on choosing the right tyres for your needs. So, whether you’re just starting out or you’re looking for an upgrade, read on!

1. What is a wheel size, anyway?

Tyre size is simply the diameter of the tyre, often measured in inches. It’s important to note that tyre size doesn’t just refer to the width of the tyre; it also includes the height of the sidewall. This is why you’ll often see two different tyre sizes for the same width – for example, a 26×1.95 tyre is different from a 26×1.75 tyre. The first number (26) refers to the wheel size measured in inches, while the second number (1.95 or 1.75 etc) refers to the width of the tyre.

Now that you know what wheel size is, let’s take a look at how it affects your ebike.

With our kits, all our 26 inch ebike conversion kits share the same wheel. It is simply the 26 inch tyre which differs. You can happily swap different 26″ tyres onto the same wheel.

eBike kits come in 26″, 27.5″ and 700C tyre sizes. The size of your wheel has a big effect on your ebike speed and performance. The larger the wheel size, the faster you’ll be able to go. However, keep in mind that larger tyres also require more power to pedal. If you’re looking for a balanced option, we recommend choosing a 700C wheel with a width of around 35mm. This should give you a good mix of speed and power. If you have a 26 or 27.5 inch bicycle, these deliver great performance too.

Of course, the best way to figure out which tyre size is right for you is to experiment. Try out a few different widths and see how they feel. After all, it’s your ebike – so make sure you choose the tyres that are perfect for you!

tyre and wheel measurement for an ebike
Learn how to measure your tyre size for an ebike kit

2. How to measure your wheel size

If you’re thinking of converting your regular bicycle into an electric bike, the first thing you’ll need to do is figure out the tyre size. This can be a little confusing, especially if you’re not familiar with bike terminology.

To measure your wheel size, simply take a look at the tyre. On the sidewall of the tyre, you’ll see a number that looks something like this: 26×1.95. This number is the tyre size. The first number (26) refers to the wheel size, while the second number (1.95) refers to the width of the tyre.

Notice that road bike tyres are measured in metric units, such as millimetres. Mountain bike tyres often use imperial units, such as inches. For instance, my mountain bike’s wheel size is 27.5 inches in diameter, and it is reported as 27.5 X 1.95 in imperial measurements but my hybrid bike reads 700 X 40C.

Commonly, the majority of adult bikes with typical wheel sizes are equipped with a standard ETRTO 622 wheel with 28, 29 or 700C tyre markings.

How to determine the wheel diameter of your bike in ETRTO.

Task 1: The simplest approach to do so is to start measuring from the centre of the wheel and work your way out toward the inner edge of the tyre, where it meets with the rim.

Task 2: Write down this measurement in millimetres. This is the inner radius of your bike tyre.

Task 3: Take the diameter (R) of the rim and multiply it by 2. The diameter is the result of this calculation. [E.g. 219×2 = 438 mm]

Task 4: Take away 10 mm from your diameter measurement. [E.g. 438-10 = 428 mm] 

Task 5: Find the closest matching size in the bike wheel size guide below, within ±3mm. For example: 438 mm = 441 mm

Calculate the size of your wheels in inches, using your tyre width and rim diameter:

Task 1: Start by measuring from one side of the hole in the middle of the wheel to the outer edge of the tyre. Write that number down. Record the number on the other side of the tyre. If your wheels are the same size on both sides, then add their measurements together. If the two measurements are different, take the larger one and subtract it from the smaller measurement. This will give you your rim diameter.

Task 2: To discover the width, take a tape measure and measure the flat surface across the tire’s tread from one side to the other.

Task 3: To find out what size your tyre is, combine the two measurements of diameter and width. The diameter of a bike tyre is commonly listed before the width.

Bicycle tyre sizes are measured in full inches. If you’re slightly over or under, round up or down to the nearest inch.

3. Tips on checking your bike tyre markings

You’ll need to double-check the measurements on your tyres because not all wheels are created equal. The figures shown in the image above indicate where you can look for this number. This is the simplest and most effective method of determining your wheel size.

For some time, various techniques have been used to measure wheel sizes. ETRTO numbers, a 5-digit number that indicates the precise diameter, are used by some people to measure bike wheels. The first two digits of the ETRTO indicate the tyre width in millimetres. The final three digits represent the inner tyre diameter.

If you have the French measures, they will be shown as a number followed by a “C.” If your tyre has UK tyre markings, an X might appear in-between two numbers, as diameter-X-width.

4. Choosing the best e-bike conversion kit for your wheel size

If you’re looking to convert your regular bike into an electric bike, you’ll need to first determine the size of your wheel.

There are a few things you’ll need to take into consideration when making your purchase, including tyre type and width, as well as rim diameter.

Check out our stocked ebike kits for more information on how to select the best ebike conversion kit for your wheel size.

Now that you know how to measure your bike’s tyre size and what to look for when selecting an ebike conversion kit, you’re one step closer to enjoying the ride.

Happy ebiking!​

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