Using the right size of the tire is essential for comfortable riding. After understanding the bike tire size, you can determine whether a bicycle suits you.
But How to Measure Bike Tire Size? The measurement of bicycle tires consists of two components-
- A larger number indicates a tire diameter,
- A smaller number indicates a tire width.
Generally, you can measure your tire in standard and ISO methods. For more information on tire measurement, please see the article.
Also, make sure to check out my post on How To Make Your Bike Faster, Quieter & Smoother?
What Does The Tire Number Mean?
The first number on your tire is its diameter.In road, gravel, fixie, and other types of bicycles, 700mm tires are commonly seen as the first number. The 650mm size is also common, found on smaller adult bikes.
The second number represents the measured width of the tire. Tire widths for metric-based bikes range from 23mm to 48mm and are even wider as gravel tires become more common.
The metric sizing may also be listed as 700c or 650b. A different letter represented a different diameter for tire bead seats in the old sizing standard. ISO sizing for tires is also available, which measures the diameter of the tire bead seat. For example, the ISO size 622 is equivalent to the 700-size tire.
Bike Tire Size Chart
| Tire Size | Width | Type |
| 29” (ISO 622) | 2.2”-3” | Mountain |
| 700C (ISO 622) | 23mm-45mm | Road/gravel |
| 27.5” (ISO 584) | 2.1”-3”3.7”-5” | MountainFat bike |
| 650b (ISO 584) | 2.2”-3”23mm-47mm | Gravel Touring |
| 26” (ISO 559) | 1.6”-3”3.7”-5” | MountainFat bike |
Ways To Measure Your Tire
You can measure tires in two ways. Most tires are measured using the standard and ISO methods.
- The Standard Method:
Use the kickstand to keep the bike upright, or lean it against a wall. Putting the bicycle upright allows you to measure its wheel without tipping over. Using a retractable metal tape measure is more durable than a plastic one if you are measuring the bike yourself.
Basically, it is the diameter of half the wheel’s radius. To calculate a tire’s diameter, multiply its length by two. Except for BMX cycles and mountain bikes, adult bicycle wheels usually measure 26 to 29 inches in diameter.
To determine the flat area of the tire, measure from one side of the tread to the other. The breadth of a tire is its distance. There are a number of uses for right size tires.
Rougher terrain requires a wider tread, while smoother, faster rides require a narrower track. First, place the diameter, then the breadth. It is important to keep in mind that traditional or standard sizes are based on their diameter first, followed by their width.
- The ISO Method:
Your bike’s tires should be measured according to the ISO standard. Millimeters are the standard measurement system for bicycle tires used by the International Organization for Standardization (ISO).
ISO sizing is the most reliable method for measuring tires at home. In this way, you will be able to get the most precise measurement possible.For easy inspection, a tire’s sidewall should also display its size. Place the bike on its kickstand or against a wall.
Please measure only the distance between the center of the wheel and the inner edge of the tire in millimeters. Two times the figure will give you the diameter. It includes the tire width and the bead seat diameter (BSD).
How To Measure Bike Tire Size?
It is quite easy to measure a tire. By following some simple steps, you can measure your bike tire size:
Step 1
Place the kickstand on the bike, or lean it against a sturdy wall.
Step 2
Measure the outer edge of the bicycle tire with a tape measure held against the center of the wheel. By traditional sizing, double the inches to find the tire diameter. You can determine the ISO diameter by measuring from the center of the wheel to only the inner edge of the tire and doubling it.
Step 3
You can measure the flat surface of a tire’s tread from one side to the other. This number indicates the width of a tire. Traditionally, tires are measured in inches, but ISO measures them in millimeters.
Step 4
Tire size is determined by combining tire diameter and tire width measurements. First, measure the tire diameter, then its width. The width is placed first in ISO sizes, followed by the diameter.
Why Do You Need To Know The Right Tire Size?
On a sidewall or spec sheet, tire size is more than a number. You need it as part of your bike setup. It is important to know the diameter and width of your bike’s tire if you want it to handle, roll, and grip well.
If your tires need to be replaced or want to test out a different size, you should know this information. Rolling over obstacles will be easier and faster with a larger tire and wheel diameter.
However, some may prefer smaller wheels due to their height or maneuverability. A narrow tire rolls faster and is lighter, while a wider tire is more stable and offers more traction.
How Do I Know My Bike Tire Size?
There are lots of sizes of bike tires, but you should be able to determine the size of yours easily. When you’re looking for a replacement tire, check the sidewalls of your current tires (both sides).
It will say something like “700x25mm” or “29×2.30”-that’s your tire size. There is also a recommended psi range and a tire model and manufacturer.
Generally, you don’t need a bike tire size measurement since the tire size is printed on it.
Frequently Asked Questions [FAQs]
When Should I Replace Bike Tires?
A bike tire needs to be replaced when the tread pattern has worn down to the point of losing grip. Additionally, riders should get new tires if they have cuts, slashes, or cracked rubber. These rubber can cause punctures over time due to normal use.
Do Bike Tires Have A Direction?
There is a specific direction in which bike tires’ tread patterns work best, and the best orientation for them is in that direction. Even road bikes with extremely low-profile or slick tread indicate how to install them on the sidewall. When mountain bike tires are pointed in the right direction, they provide maximum traction.
Final Words
So, measuring tire size is a simple task. Every biker should learn how to measure a bike tire. You need this information when replacing the tire on your bike.
It is printed on the tire but can become unreadable over time. Measure your bicycle tire to determine its size.
Also, you have to check out my post on the 15 Essential Bike Tools You’ll Always Want To Have On Hand.
