Introduction
In the past, 23mm was the typical width for most road tires, and some came in a 20mm width or narrower. In the last few years, road bikes have seen an increase in the use of wider tires. Nowadays, the narrowest tire commonly fitted to road bikes is 25mm, and many bikes come with 28mm tires. On some of the latest models, there is clearance for 32mm rubber and even wider tires. Wider tires can provide better grip, increased comfort, and reduced rolling resistance.
This guide will assist you in determining the tire width that suits your riding style and the conditions you ride in.
Bike Tire Sizing Systems
Throughout history, different countries have used their own methods of marking bike sizes, resulting in variations in the numbers used to identify the same size tire. With cycling becoming increasingly popular worldwide, there was a need for a standardized approach to make things easier for everyone.
Traditional sizing systems for tires are based on the outer diameter of an inflated tire, which is measured in inches or millimeters. However, the ISO standard notation for tire sizing uses the diameter of the wheel bead seat in millimeters, followed by the width of the inflated tire in millimeters.
Tire sizes in inches are identified by specifying the width in decimal (such as 26 x 1.75) or fraction (such as 26 x 1 3/4). However, even though two size identifications may seem equal mathematically, they can refer to different tire sizes that are not interchangeable. For instance, 28 x 1 1/2 is not the same size as 28 x 1.50.
Credit from: biketiresize
The tire size can be found on the sidewall of the tire and is indicated by two numbers that generally correspond to the outside or inside diameter and the tire's width. These numbers may be confusing at first, but they are actually quite simple. Additionally, a tire may have one, two, or even three sets of sizing numbers. If one of these sets of numbers on a new tire matches the markings on your old tire, the new tire should fit on your rim.
Common Road Bike Tyre Sizes
Here's an overview of common road bike tyre sizes.
ETRTO | Dimensions |
---|---|
18–622 | 700×18c |
23–622 | 700×23c |
25–622 | 700×25c |
28–622 | 700×28c |
30-622 | 700×30c |
32–622 | 700×32c |
How To Choose
Aerodynamics
There is a common concern that wider tires may be less aerodynamic efficient than narrower ones. However, various studies have shown that a combination of slightly wider tires and wider rims can actually improve aerodynamic performance. This is because wider tires and rims create a smoother transition between the tire and the rim, which results in reduced turbulence and drag. Recent studies have shown that wider tires, such as 28mm or even 30mm, can be faster than narrow ones. This is because a larger contact patch with the road is created by wider tires, which results in less rolling resistance and a smoother ride. Furthermore, wider tires can be run at lower pressures, which can reduce rolling resistance even more and increase comfort.
Credit from: Cyclist
Comfort
Wider tires offer various benefits, including increased comfort. These tires can be run at lower pressures, which allows them to absorb more shock and vibration from the road. As a result, they provide a smoother and more comfortable ride, particularly on rough or uneven roads. In addition, wider tires offer better traction and stability, which leads to improved confidence and control when riding.
Credit from: Cyclist
Terrain Suitability
When it comes to riding on smooth roads, it's best to use 25c tires as they reduce rolling friction during races or interval sessions. For most paved terrain, 28c-30c tires are a good choice. However, if you ride on rough roads or you are a heavier rider, then a 30c or 32c tire may be a better option.
Credit from: Cyclist
Frame Clearance
Always check that brakes, chainstays, and forks have adequate room before sizing up. Most road frames comfortably accept 25c-28c tires. Wider 30c tires may require switching to wider internal rim widths on some frames. The 32c size pushes clearance limits on all but endurance-focused designs. Typically, bike manufacturers specify the maximum tire width for each model in their range and a safe clearance range between the tire and frame. You can usually find this information on the manufacturer's website.