Road Bike Tire Names, Sizes, and Standards

Easy Road Tire Sizes and Standards Guide

Road bike tires generally differ in the following three areas

1. size
2. type
3. bead type

For example, for the popular “Continental GRAND PRIX 5000 700 x 25C Clincher Foldable” road bike tire, the product name alone tells us the following

1. size: 700 x 25C
2. type: clincher (tubed)
3. bead type: foldable

To find out if the tire can be used on your road bike, you only need to know the size and type of the tire, so first find out the size and type of the tire that is currently installed on your bike, and then choose one with the same standard.

Tire Size (Standard)

While inch size is the established standard for bicycles for the general public in Japan, road bicycles are described in the European standard called the ETRTO standard, instead of inches.

In the ETRTO standard, tire size is expressed as “diameter x thickness. For road bike tires, this is indicated by the combination of the number 700, which is the diameter of the tire (700 mm), and the number 00 C, which indicates the thickness of the tire. The current mainstream tire size is “700 x 25C,” which means “700 mm in diameter and 25 mm in thickness.

Tire size depends on the tire clearance between the frame/fork of the road bike used and the brakes. Note that if you install a tire of a size that exceeds the clearance, it may rub against the brakes or frame, making it impossible to ride or damaging the frame.

For caliper brake type road bikes, the maximum tire size is listed in the brake specifications, so if that is cleared, it will generally fit.

Tire Type

Clincher / Tubed

The type of tire familiar to city cyclists, in which a tube is inserted inside the tire, is called a “clincher tire” or “tubed tire. Sometimes abbreviated as “CL” in wheel product names.

Most tires used on road bikes are clincher tires. They can be used on tubeless ready wheels as well as clincher wheels.

Clincher tires are mounted by fitting the bead of the tire to the rim of the wheel, making them easy to remove, easy to replace the tube when repairing a puncture, and inexpensive.

On the other hand, they also have the disadvantage of being prone to “rimming punctures,” which occur when the tire and inner tube become misaligned, creating friction and puncturing the tube between the wheel rim and tire when the rider rides over a bump.

Tubular

A tubular tire is mounted by placing a tire with an inner tube encased over the rim of the tire. They can only be used on tubular-only wheels. Sometimes abbreviated as “TUB.

In contrast to clinchers, where the inner tube is in contact with the wheel rim, tubular tires have the advantage of being puncture-resistant because the inner tube is completely encased in the tire. Also, since the inner tube is sewn into the tire, friction between the tire and tube is reduced, which is said to result in less power loss when riding.

On the other hand, the fact that the inner tube is sewn into the tire means that the tire is not easy to maintain in the event of a puncture, since in the event of a puncture, the sewn system must be unraveled and the inner tube removed for repair.

Tubeless

Tubeless tires are a new type of tire that does not require a tube to be placed inside the tire. It is sometimes referred to as a “TL (Tube Less)” tire.

The construction is the same as a clincher with the bead fitted to the rim, but it can only be used on tubeless compatible wheels. Since there is no inner tube, the tire has the advantage of high running performance even at low air pressure and does not need to worry about the replacement life of the tube.

Another advantage of tubeless tires is that they have an air retention layer on the inside of the tire, so unlike tubeless-ready tires (discussed below), they do not require sealant and require less effort.

On the other hand, the disadvantage is that when mounting the tire, it is necessary to inflate the tire all at once at high pressure to raise the bead firmly, so it is better to have a special pump for removing and installing the tire, and other operations are different from normal inflation.

Tubeless Ready

A tubeless ready tire is a tire that does not require the same inner tube as a tubeless tire, but does require sealant. They are sometimes referred to as “TLR” (Tube Less Ready) tires.

Unlike tubeless tires, TLR tires do not have an air retention layer, so a special liquid called sealant is used to maintain the internal pressure of the tire, filling the gap between the tire and the rim to prevent air leakage.

Mechanistically, it is similar to a clincher, but it can only be used in combination with tubeless-ready tires and tubeless-ready wheels.

The disadvantage is that the sealant needs to be replaced two or three times a year, which is probably more time-consuming to operate than tubeless tires.

Tire Bead Types

Wire beads

Tires displayed in bicycle shops as a ring are so-called “wire bead” tires, which have a metal wire in the bead. Because they are metal, they cannot be bent, so they are displayed as they are in a loop.

The biggest advantage of wire bead tires is price; most tires priced under $30 per tire are wire beads.

The disadvantages of wire beads are that the tires are heavy because they contain metal wires, and they are inconvenient to carry because they cannot be folded. Also, because of the metal wire, it is inconvenient to replace the tire.

Kevlar beads (Foldable Folding)

Instead of using wires to hold the bead in place, tires with Kevlar beads are braided with Kevlar fibers. Because the fiber allows the tire to be folded, it is also called a “folderable (folding) tire,” and some tires weigh less than 200 g per tire.

The disadvantage is price, which can be two to three times the price of a wire bead tire, with the highest grade costing more than $100 per tire.

Surface Finish

Tread pattern

When you think of a bicycle tire, you may think of a tire with a tread pattern that has grooves on the front surface. When riding on rough roads that are not paved, it is easier to ride with a tread pattern because it engages with the ground.

However, the grooves have the disadvantages of less grip, power loss, and higher rolling resistance due to less ground contact area between the road surface and the tire.

However, there are many higher grade tires for road bikes that are designed to have a tread pattern but lower rolling resistance.

Slick Tires

Slick tires without grooves are used in road racing. The lack of grooves allows for a larger ground contact area with the road surface, providing superior grip and a lighter ride with less rolling resistance.

On the other hand, the lack of grooves has the disadvantage that the tire wears out more quickly because all surfaces of the tire are used to catch the road.

When we think of slick tires, we tend to think, “Well, they don’t have grooves, so aren’t they prone to slipping?” In fact, the “hydroplaning phenomenon,” which is considered to be the cause of slipping on wet road surfaces, is said to occur more frequently at speeds of 80 km or more, so there is no need to worry about it on a road bike ridden by an average rider.

Does the type of valve have anything to do with the tire?

One of the differences between road bikes and regular bicycles is the type of valves.

The most widespread type of tube in Japan is the tube with English valves, while most road bikes have French valves. However, the type of valve is the standard for the tube, not the tire, so the tire side does not require a valve standard.

However, each model of bicycle tire has its own air pressure specifications, and most road bike tires are designed for high pressure, so most of them use tubes with French valves instead of English valves, which cannot be used for high pressure.