All manufacturers extend a lot of research, time, and money into ensuring that every motorcycle rolling out of their factory boasts a fine set of tyres. The decision to pick a specific set of tyres for a motorcycle is arrived upon based on the use case of the vehicle, along with years of experience and data. Sometimes, however, a rider’s specific requirements or the prevailing riding conditions may be different from what the bike manufacturer designed the model for. In such cases, a replacement tyre preferred by the rider may differ in character from what came in as a stock fitment. Whenever such a situation arises, a motorcycle owner would do well to understand all the basics about a tyre to ensure that the replacement tyre matches his requirements well. Easy as it might sound at first, it can be a daunting task to really understand your needs and make the right choice. It is also a matter of safety, as choosing the wrong tyre for your specific riding requirements might end up doing more harm than good, even if it’s the most expensive tyre set that you bought. There are a lot of technical terms and variables that you need to keep in mind as you decide to replace your motorcycle tyre with a choice other than the one recommended by the manufacturer. To make it simple, in this article, we will try to explain what all components a tyre is made of the different varieties available, and other basics you need to acquaint yourself with before you pick the replacement rubber. Let’s get going with this.
When to change the tyres
Tyres are one of the most important components of any road going vehicle. They are the only part in contact with the road when you are riding. Think of tyres as shoes for your motorcycles. Just like your shoes wear out over time with use, so do the tyres. Even if you don’t wish to change the make and model, here are some of the reasons why you would want to replace your two-wheeler’s tyres.
● Tread wear: Look at the tread on your vehicle’s tyres. Over time, with use, the tread depth will reduce and that indicates that the tyre is wearing off. Different varieties of tyres would wear out to different tread depths before they need replacement. Some tyres also have an indicator on them and once the tread wear goes beyond that mark, it is time to look for a new set.
● Bulges: Sometimes a tyre would develop a bulge. This could be because of high temperature, improper tyre pressure, bad roads, or poor tyre quality. If you see the slightest of bulges on any of your vehicle’s tyres, it is time to replace them immediately, even if the tread is in good condition. The bulge carries the risk of cracking or bursting, and that could lead to a very bad mishap.
● Cracks: If you do not use your motorcycle often and it has been stationary in extreme weather conditions, it can develop cracks. These cracks can cause the tyre to burst. Cracks are irreparable and a replacement will be necessary to fix the issue.
● Damaged sidewall: Another irreparable damage. If the sidewall has the slightest of the cuts, it is impossible to repair it, especially on tubeless tyres. Either way, it will be safer to change the tyre if any side wall damage is observed.
Now that you know when to get the tyres of your two-wheeler replaced, let’s look at what kind of tyre you should get for your motorcycle. To make things simpler, let’s understand the basic construction of a tyre first.
Basic Tyre Construction
Tyres are not made only of rubber. Underneath that visible layer of grippy rubber, you have various components holding it all together. While different types of tyres may vary marginally in construction and materials, the basic construction of a tyre is consistent.
Tread: You see different shapes and knobs on tyres? That’s the tread. The ridge-like pattern that you see on the rubber that meets the road isn’t just meant for aesthetic purposes - these varied tread patterns offer enhanced grip and control in different riding conditions. Each tyre model has its own unique tread pattern, and a manufacturer-recommended minimum tread depth. The tread depth of an in-use tyre is the first indicator of its health and road worthiness.
Carcass: No, it’s not some dead body hidden in the tyre. However, you can refer to it as the skeleton of the tyre. Like the human skeleton gives structure to the human body, the carcass gives structure to the tyre. The carcass is mostly made up of materials like steel, nylon fibre, polyester, fibreglass, etc. These materials give the tyres their structural strength. The pattern and formation of the carcass depends on the type of tyre.
Bead: The bead refers to the part of the tyre that tucks under the rim of the wheel. It has a steel wire construction to give it structural strength. The bead tightly fits into the rim so that there is no chance of air escaping, especially in tubeless tyres. It also keeps the tyre from slipping from the rim when the wheel is in motion.
Sidewall: The sidewall, as the name suggests is the side of the tyre. It lies between the tread and the bead. The sidewalls can be of different widths depending on the purpose of the tyre. The sidewall gives the tyre its handling cred. The tightness of the sidewall also impacts the ride quality.
Reading the tyre markings
Each tyre comes with markings, which are mostly alpha-numeric, and pack in a lot of information about the tyre in just a few alphabets and numbers. Therefore, it is good to know how to read these tyre markings. Let’s take a tyre for example with markings that read 190 / 70 R17
Tyre width: the first two or three digits of the marking represent the section width in millimetres, measured from the widest parts of sidewall to sidewall (not the contact patch) with the tyre inflated to its correct specification. So, the number 190 in our example represents a 190 mm wide tyre. This is followed by a forward slash “/ “ for separating the next number.
Aspect ratio or profile : The next number denotes the aspect ratio. This represents the height of the sidewall or the profile of the tyre. Aspect ratio is typically denoted as a percentage of the section width of the tyre. In our example it’s 70, which means that the height of the tyre’s sidewall is 70% of its nominal sectional width or less.
Tyre construction : Sometimes (but not in all cases) the aspect ratio is followed by a code indicating the construction type of the tyre. The code is represented by an alphabet, and this is what it means
- B: Bias belt or bias ply construction
- R: Radial tyres
In our example, the tyre is a radial, since it has an R marking on it.
Diameter: The number right after the tyre construction alphabet denotes the diameter of the wheel. In our example it’s 17, which means that the tyre is meant for 17-inch wheels.
Now that you know what the tyres are made up of and how to read their markings, it is time to learn how to choose the right tyre for your motorcycle.
Replacing stock with stock
You don’t want to go through the tyre selection process and want to keep it simple? Just replace the old tyres with new ones of the same kind. In most cases, stock tyres perfectly suit the requirements of the target customer. For a straight replacement, just go to a dealership of the tyre’s make, and ask for the exact same model. It does not get any simpler than this.
Stick to the recommended specs
If you are not happy with the set of tyres that your motorcycle came installed with, you can choose to get a different set. There are always more expensive tyres available in the market with superior grip, or other features that suit your requirements more specifically. However, there is a strict guideline to remember. Replace the tyres with the OEMs recommended specification only. The manufacturer knows what size of tyres will suit the motorcycle best. Buying anything that is above or below the specified range in terms of size is generally not recommended.
Tubeless vs tube tyres
If your motorcycle has spoked wheels, you should be going for tube tyres, as spoked wheels allowing for tubeless tyres are still quite rare, and expensive. Spoked wheels do not have the capability to be airtight and hence you cannot switch from tube to tubeless tyres. If you have alloy wheels on the motorcycle, you can go with tubeless tyres. Tubeless tyres are better built, offer better traction, can be easily repaired in case of a puncture, and are generally preferable over tube tyres.
Radial vs bias tyres
Like we said earlier, it will be wise to go with the manufacturer’s recommendation; however, if you feel that you want a different type of construction on the tyre, you may choose to select between radial or bias ply tyres. Radial tyres, in general, work well in applications where high speed, mid corner handling and faster rate of heat dissipation are the key requisites. These tyres, owing to their more flexible sidewalls, also offer a fantastic transverse contact patch, allowing the rider to lean in their motorcycle more aggressively. So, if your motorcycle is fitted with bias ply tyres and you want something that could fulfil the application, you may go with radial tyres.
If you are going to ride off-road, you will need block pattern or knobby tyres with extra strong and bigger tread that will allow the tire to dig into loose gravel or mud to find grip. For the road, however, moderate tread works just fine. For track specific, dry weather tyres, you will need very little tread on the tyre, however, the rubber compound must be extremely soft and sticky for maximum grip. For snowy and wet conditions, there are special tyres with unique tread patterns that allow for maximum grip and disperse water more easily.
For spirited riding and corner carving, you will need a set that has stiff sidewalls and a round contact patch that allows for hard leaning. This increases the grip of the motorcycle while cornering. For a more comfortable and relaxed ride, the sidewalls can be softer, and the contact patch can be relatively flatter. Again, stick to the OEMs recommendation.
You will have to go for a tyre size that will match the rim diameter, although the tyre’s aspect ratio, or its sidewall height, in relation with its width can be substituted within a limited range. Remember, though, that a tyre acts as the primary suspension for any vehicle, and smaller aspect ratio, or shorter sidewall will generally affect the ride quality adversely. The upshot here is better handling and control.
At the end of the day, a good tyre should allow you to enjoy your motorcycle with comfort and confidence. As we mentioned at the beginning, going with the manufacturer recommended specs is generally the best option. If you must, however, replace your tyres with a unit other than the one recommended by the maker, we hope this comprehensive guide went some way in helping you choose better.