Tires, as consumables, are easily worn out. The degree of tire wear is related to factors such as the number of tire revolutions, motorcycle speed, road conditions, load-bearing capacity, riding habits, and maintenance conditions. We understand motorcycle tire knowledge in order to reduce tire wear and also to avoid danger caused by ignorance.

Tire Classification (Many types of tires exist, but this introduction focuses on the controversial and popular types)

Hot Melt Tires: (Of course, there are also regular tires that are neither semi-hot melt nor hot melt. These will not be covered here.) There are many types of tire classifications. The first one introduced here is the commonly mentioned hot melt tire. As the name suggests, hot melt tires have a low melting temperature. After a slightly aggressive ride, the tread will be heated and softened, resulting in a phenomenon of rubber peeling off. After softening, the friction of the rubber will increase significantly, and the grip will be noticeably enhanced.

However, these tires also have their downsides. The most typical is the short lifespan and high consumption. Additionally, road debris such as sand and gravel can penetrate the tire, since the melted rubber is very soft. Tires with debris can affect the grip. These tires are mostly used on clean tracks, and their tread patterns are generally very limited. Hot melt tires without tread patterns are also known as “slick tires”.

Semi-Hot Melt Tires: Considering the limitations of hot melt tires outside of tracks, semi-hot melt tires were introduced. These tires combine the advantages of regular tires and hot melt tires. After the tire temperature rises, they not only have strong grip but also ensure sufficient hardness to prevent road debris such as stones from penetrating the tire. The wear level is also controlled within an acceptable range. Most of the sports tires promoted by manufacturers are semi-hot melt tires, and they are popular among performance enthusiasts in the market.

Radial Tires and Bias-ply Tires: (There are also arched tires, etc., which will not be introduced here)

Radial tires, which are vacuum tires, are worth mentioning. What are vacuum tires? Vacuum tires are a type of low-pressure inflatable tire. These tires use a special construction of the rim’s flange and the edge of the tire to seal air within the tire body. Good vacuum tires are difficult to puncture, and even if they are damaged by foreign objects, the air will not disappear immediately. Moreover, they are easy to repair after a blowout. Vacuum tires have high elasticity and wear resistance, as well as good adhesion and heat dissipation performance, especially the all-steel radial vacuum tires.

Radial tires (radial tire) are very common. The standards for measuring tires are different, so the classifications are different, and many classifications can be interchanged. The radial indicates the structural form of the tire, which mainly distinguishes between bias-ply tires, arched tires, pressure-regulating tires, etc. The international code for radial tires is “R,” commonly known as “steel wire tires.” The R in the common tire specification 140/70R -17 indicates that it is a radial tire. Generally, most cruising motorcycles use bias-ply tires, while most sport motorcycles use radial tires.

Generally, spoke wheel tires require inner tubes, but BMW’s GS series has a very interesting design – spoke rim vacuum tires. The Germans ingeniously solved this problem by not connecting the spokes to the tire but rather to the rim edge. Bias-ply tires have a rounder profile and higher sidewalls, while radial tires have a flatter profile and shorter sidewalls.

If classified based on the presence or absence of inner tubes, tires can be divided into two main categories. The first category is vacuum tires (tubeless tires) introduced earlier. The other category is tires with inner tubes. These tires have certain benefits: the tire air is located inside the inner tube, so precise contact between the tire and the rim is not strictly required. The air pressure is low, and there’s no need to worry about tire deflation or air leakage. This type of tire is commonly used on off-road vehicles and American-style street cars with rims and wire spokes.

Rain Tires and Dry Tires: (There are also wet-dry tires) Rain tires are designed to handle rainy days. These tires were created to effectively drain water on rainy days, as everyone knows that on rainy days, a film of water can form between the tire and the road surface, reducing the tire’s grip to almost zero. Hence, rain tires were introduced, with dense tread patterns that actually serve as drainage channels. The design of these channels is based on vehicle parameters to determine the drainage volume per second, and a common important parameter for rain tires is how many L/S they can drain. Rain tires are further divided into heavy rain tires and light rain tires. Heavy rain tires have wider and deeper grooves, providing greater drainage capacity, which means they also have smaller contact areas with the ground. They are used only in heavier rain. In contrast, dry tires have fewer tread patterns compared to rain tires, and some people also call them dry weather tires. Dry tires and rain tires have different rubber formulas, and their hardness levels are different.

Tire Parameters

Tires have specific specifications, and understanding the specifications of a tire can effectively prevent some hidden issues. A qualified tire will have information such as specifications, maximum load, inflation pressure, standard rim, brand, etc. For example, the tire specification is 110/70R-17 H54. These parameters all have specific meanings:

110 indicates a tire width of 110mm, which we often refer to as the thickness of the tire.

The 70 after the / indicates the aspect ratio (%), which means the height is 70% of the width. The lower the aspect ratio, the flatter the tire. Generally, sports cars have wide and flat tires, such as 180/55R.

R indicates it is a radial tire.

The 17 after the – indicates the tire’s inner diameter is 17 inches (1 inch = 2.54cm).

H indicates a maximum speed of 210 km/h.

54 indicates a maximum load of 212 kg.

The H54 parameter can be referenced to a specific speed and load chart, indicating it is safe within this range.

However, many tires do not have the aspect ratio parameter marked, so don’t worry, this is not an irregular tire. In fact, this represents that the aspect ratio of the tire is 100%, meaning the width is equal to the height. Sometimes, some tire specifications are followed by the ply rating strength, such as 2.75-17-4pr, which indicates that the tire’s sectional width is 2.75 inches, the inner diameter of the tire is 17 inches, and 4pr indicates that the tire’s ply is 4 layers.

Tire Purchase

For motorcycles, the forces on the front and rear wheels are different. For many bikes, especially cruising bikes, the rear wheel is the dominant load-bearing wheel, so the wear on the rear wheel is always greater than that on the front wheel. Generally, the rear wheel is easier to replace. When selecting a tire, you can’t blindly choose. The most important thing is the tire specification. The tire specification must be correct. If it’s incorrect, it can be dangerous, and you might not even be able to install it. However, the fork width of many bikes limits the width of the tire. If it’s too wide, it can’t be installed. Even if it’s barely installed, it can rub against the chain or the fork, causing potential problems. Many people always like wide tires. Here’s a reminder: wide tires are not absolutely good. Many bikes are carefully tuned after they leave the factory. Randomly changing tires and intentionally widening them can affect the overall performance of the vehicle and even have a negative impact on power reduction.

Tread Pattern Selection

The tread pattern is still an important indicator that determines tire performance. The shape of the tread pattern determines its drainage capability and ability to remove other debris, and it also affects the tire’s grip. Therefore, choosing the appropriate tread pattern is very important. There are dozens of tread patterns for the same specification of tire, and generally, bikers should choose the appropriate tread pattern based on their actual situation.

If you often drive on mountain roads, mud roads, snowy roads, icy roads, etc., you should choose tires with wide and deep grooves in the off-road style. Because the grooves are deep and wide, under the rotation of the wheels, the action of centrifugal force helps to drain water and other debris, allowing the tire to better contact the ground.

If you often drive on highways, you should choose tires with hidden and densely packed grooves. These tires have a large contact area with the ground when driving on the highway, ensuring safe driving. If you’re racing on a track, you can choose slick tires (no tread pattern). Slick tires need to be preheated and will significantly improve grip only after reaching the normal working temperature of the tire.

Tire Maintenance

Many bikers only focus on engine maintenance and neglect tire maintenance, but tire maintenance should also be taken seriously, as problems with the tires can be fatal for the rider. Tire maintenance can be discussed from two aspects: road conditions and human factors. Road conditions are often beyond our control. We have no choice but to take the road that lies ahead, such as muddy roads or gravel roads. In this case, we can only be careful or try to detour as much as possible. Human factors include practices such as wheelies, hard braking, burnouts, and drifting around corners. All of these practices are very damaging to the tires.

The rider’s daily driving habits are also crucial. Good driving habits can effectively prolong the life of the tires and greatly help the engine, whether accelerating or stopping. You should avoid sudden stops and starts, and be sure to shift gears frequently on the road. Also, if you find that the wear on the left and right sides of the tire is different, you should pay attention. Uneven wear is one of the fastest ways to wear out a tire and is generally caused by factors such as different scales on the left and right chain wheel adjusters or misalignment of the front and rear wheels.

Tire Life and Replacement

I previously encountered an elderly man at a tire shop, and I noticed that his tires had already started cracking, showing obvious signs of aging. I casually mentioned, “Sir, it’s time to change your tires.” However, his answer surprised me: “There are still tread patterns left, I’ll change them when they are worn out.” To ensure everyone’s safety while riding, I would like to provide some basic information about tire life to beginners.

Two factors need to be considered when replacing tires: the age of the tire and the wear indicator. The age of the tire is calculated from the manufacturing date, and the effective safe period is 3-5 years. If the tire exceeds this age limit, it should be replaced, even if it has never been used. This is because rubber will age and harden over time, and the resulting cracks can pose significant risks.

You can carefully look at the other numbers on the tire, such as the tire marked with 2410, which means it was manufactured in the 24th week of 2010.

The wear indicator mainly refers to the tread pattern. Many tires from the factory have colored lines, which serve as a scale. If the line wears out, it means the tire has just passed the break-in period, and its maximum performance and friction have just begun.

Then look at the middle part of the tire. If there is a tread pattern in the middle and it wears out, replace it as soon as possible because the middle part wears out the fastest. The same applies to tires with tread patterns on the sides but not in the middle; you should also look at the degree of wear on the tread pattern. Tires should be replaced after a certain number of kilometers (the specific number varies depending on the type of tire). For tires with tread patterns, the grooves between the tread patterns should not be less than 2 mm. If the grooves are not very obvious, it will affect the grip, causing side-sliding during turns or even blowouts at high speeds, which is extremely dangerous.

Tire pressure is also crucial. Insufficient tire pressure will increase resistance, while excessive tire pressure will reduce friction. Check the tire pressure regularly and inflate the tires according to the specified pressure, as the amount of pressure directly affects the tire’s lifespan and performance.