What Are Tyres?
A vehicle that stands upright on the circular, ring-like thing, which is also the only contact of the vehicle with the ground, found mostly in black colour, is known as a tyre (or tire). Fitted on the round metal rim, tyres are usually filled with compressed air and nowadays with nitrogen too. An ideal tyre is expected to deliver certain aspects such as durability, grip, comfort, and overall cost. The integration of all these vital characteristics in a tyre makes it one of the most complex products to design and develop.
Just like a smartphone, tyres too, during their making, go through a great amount of R&D, testing and simulation procedures. Besides, natural rubber forming the basis of a tyre other essential components used in the making of a tyre includes fabric, steel wires, silica, synthetic rubber, carbon black, etc. The tyres are found on various motorized and non-motorized vehicles right from bicycles to aircraft.
Categorization Of Tyres By Construction
In general terms, the tyres are classified into tube type (the ones with tube) and tubeless (the ones without tube) tyres. Moreover, as per their capability and carcass structure, the construction of tyres is broadly characterized into three main types – radial ply, cross-ply or bias-ply and belted-bias ply.
Cross-ply or bias-ply
Seen seldom, cross-ply or bias-ply tyres were found on yesteryear passenger cars and vans. Its construction comprised of a series of ply cords placed at 30-40 degree angles in a criss-cross pattern, which forms a frame (carcass) and above it rubber is integrated that forms a tyre. The cross-ply tyres possess rigid sidewalls that offer less comfort, while high friction levels result in low fuel efficiency.
The modern-day four-wheeler tyres, especially passenger car tyres, majorly come with radial ply construction. These highly advanced tyres see ply cords running at 90 degrees in the radial direction instead of criss-cross design as seen in bias/cross-ply tyres. Due to their soft sidewall, they offer more flexibility and absorb road surface undulation more effectively.
A blend of radial-ply and cross/bias-ply construction is known as belted-bias ply construction. Manufactured similar to the cross/bias-ply tyre pattern, these tyres have stabilizer belts above the regular tyre ply. The stabilizer belts are made of steel or other corded substance and are employed at different angles to the plies providing extra support to the inner material that bond with the tread.
What Are Wheels?
In simple terms, a round object with a hub and an axle, which also includes tyre sometimes, is called a wheel. Not to mix with ‘tyre’, a tyre is the rubber part of a wheel or rim that is in direct contact with the surface. Besides aesthetic elegance, the rim or wheel also play a vital role with respect to overall stability, comfort and performance of the vehicle.
Wheels come in two variations i.e. steel and alloy. The steel wheels have silver or black paint and are quite plain in terms of design. Moreover, the alloy wheels are of aluminium metal and are offered in an extensive and appealing range of paint finishes, designs and sizes. The stylish looking aluminium alloys are more robust and lightweight than steel wheels. Also, the alloys are strong enough to sustain any accidental impact without deformation or bend and are rust-free. Whereas, steel wheels bend easily and require more maintenance.
What Is Tyre Alignment & Tyre Balancing?
Tyre alignment and tyre balancing are also known as wheel alignment and wheel balancing. Although tyre balancing and tyre alignment are different from each other, however most of the times they are mixed up with each other. Be it enhanced life or optimum performance of your tyres, both the services are necessary from time to time. Wheel alignment should be performed as and when needed, while wheel balancing is a task to be carried out regularly.
In addition to extended life and uniform wear of a tyre, the tyre alignment or wheel alignment service also aids in enhanced handling. Alongside, it also evades your car from uninvited troubles such as dragging in one direction or juddering oddly on the road. Primarily, alignment is more or less the adjustment of a car’s suspension. The suspension forms the connection between the car and its wheels and ensures ride comfort and vehicle stability. Hence, it’s not merely the adjustment of tyres, but the adjustment of the angles of the tyres via suspension, which comes into contact with the surface.
Signs that indicate the need for tyre alignment
There are more than one ways to check if your car tyre requires tyre alignment service. If you observe any of these signs, you need alignment check-up of your tyre at once.
The first and foremost thing you need to check is the wearing of the tread. Is it uniform or uneven? Uniform wear will see even wear all across the tread, while partial wear of the tread at one side and comparatively lesser wear on the other indicate uneven wear. Others symptoms include the car pulling in either direction (left/right), steering wheel not in the centre even while driving straight, vibration feels on the steering, etc.
When tyre alignment becomes a must
Premature and uneven wearing of a tyre happens due to improper wheel or misalignment of the tyre. Some of the key factors that contribute to the undue tread wear comprise of feathering, camber wear, heel/toe wear.
Feathering at the tyre tread can be witnessed when the tread is as smooth as “feather” on one side and looks unused or sharp on the other side. This is a symptom of poor toe alignment in a tyre.
More than recommended or excessive inward or outward lean angle from the centre line of the tyre is known as negative and positive camber, which reflects improper alignment. Camber wear is the damage done at the inside or outside of the tread. Here one of either side is extensively more worn against the centre of the tread. Be it positive or negative camber, both result in this type of wear.
Heel or toe wear happens when one side of the lug or blocks at the tread observe faster wear compared to the other side circumferentially and appears like saw teeth. The causes of this damage can be (a) no timely rotation of tyres (b) under inflation, overload (c) abrupt braking and quick acceleration.
Though sounds similar, but tyre balancing aka wheel balancing is different from tyre alignment. The process of tyre balancing involves equalization of the combined weight of tyre and wheel assembly to ensure a smooth high-speed run. Performed alongside tyre alignment, this balancing act is done by placing the tyre and wheel assembly on a balancer. The balancing equipment centres the wheel and rotates it to establish where the weight should go. Basically, there are two kinds of tyre/wheel imbalances – static (single plane) and dynamic (dual plane).
Static balancing is intended towards addressing balance on only a single plane i.e. the vertical movement which may cause vibration. Moreover, the dynamic imbalance, gets the balance sorted on two planes i.e. vertical movement and lateral movement. Again, just as static balance, to address this kind of imbalance a balancing machine is needed.
So, in a nutshell, similar to tyre/wheel alignment, tyre balancing is also essential in order to avoid faster tread wear and ensure improved tread life. Under India-specific conditions, it is recommended to perform the tyre/wheel alignment and balancing roughly at every 7,500 – 10,000 kilometres.
Rim Size V. Tyre Size: The Correlation
To enhance the performance and looks of your vehicle you want to increase its width. However, once you reach the local market or surf over the internet you find there are numerous tyre and rim options available. And every tyre size is designed to fit specific rim size, which means all tyres won’t fit all rims. After knowing all this, it may put you in a discouraging situation. Although it may seem like an uphill task, to begin with, once you are familiar with how to measure rim and tyre size, you can see them work in tandem.
Usually, when you say 15-inch or 16-inch tyre, it’s not exactly the tyre size you utter, but technically the rim size of a tyre. The hollow space in the centre of the tyre is where the steel or alloy wheel is placed is called rim. The rim is measured in inches from the top of the rim straight across to the bottom. As per the make and variants of a car, manufacturers shod and offer the same car with separate rim size options.
There are three main attributes that comprise a tyre size;
(a) Width of the tyre, which refers to the broadness of the tyre.
(b) Height aka aspect ratio is the height of tyre sidewall to its width.
(c) The diameter of the tyre’s inner circumference measured in inches.
The tyre dimensions are marked or embossed on the tyre sidewall. The alphanumeric imprints are separated by forwarding slashes. The letters are mostly marked in black colour and are rarely seen in white. For instance, a tyre with 205/55 R 16 marking means it possesses a width of 205 mm, while the sidewall height i.e. 55 is the percentage of the total width of the tyre. Moreover, the letter R indicates construction type, which is ‘radial’ and 16 is given in inches, which means 16-inch rim will be the best fit for this tyre.
Likewise, there are tyres of particular rim size that can be fitted to some other rim sizes too, besides the given, but not all. Hence, you cannot fit tyres of any size to any rim size, as there is completely different mathematics behind it, which we covered earlier in Tyre Upsizing – A Quick & Complete Guide For Beginners. Instead of drawing to an abrupt conclusion in haste with respect to choosing the right tyre and rim size you can always contact any reliable tyre expert for help and suggestions.
How Rim & Tyre Ensure Smooth Ride Quality
On one hand, ideal tyre and rim size can assure you smooth running and optimal overall performance. While on the other side, incorrect pairing can impact the fuel economy, comfort and noise levels drastically, as both are interlinked with each other quite closely.
So, if you are mulling over to change the size of your rims/wheels (upsizing), you will be required to alter the size of the existing tyre too. You need to choose the right rim/wheel and tyre ratio carefully to ascertain that the overall diameter of the rim/wheel and tyre combination remains unchanged. Or else, the odometer and speedometer settings and other performance-related aspects will get affected badly. In order to prevent any hassle or breakdown when on the road you should go through this helpful link Tyre Upsizing – A Quick & Complete Guide For Beginners for better understanding.
During upsizing when the tyre sidewall height sees a cut, performance and comfort are enhanced and handling/stability too sees an improvement. On a bit downside, the road/tyre noise may become evident as larger rims call for more NVH (noise, vibration, harshness) levels compared to small rim tyres. However, the noise aspect may vary from brand to brand and type of tyre you choose for your vehicle. Remember, that larger wheels/tyres offer exceptional ride quality on highways and longer routes, while in a city environment smaller or OEM recommended wheels/tyres provide decent comfort under potholed and rougher road situations.
Large alloy wheel & tyres
The large size alloys with fatter tyres do adorn the presence of the vehicle. But on the flipside beware of the dripping fuel economy as bigger wheels and bigger tyres consume more energy hence high rolling resistance. Moreover, the added weight of the large tyre and rim increases the overall weight of the vehicle thus negatively affecting the efficiency of fuel.
So, prior to swapping your old or under-performing tyre to new ones you need to be specific about your expectation from the new set of tyres. Because if you are looking for improved handling and performance, the option of upsizing is open for you, however, if you demand better NVH levels and comfort alongside better city fuel economy smaller or recommended wheels make sense.
Also, there are scenarios where just by changing the tyre brand and tyre type can get the issues ironed out without the need of changing tyre size. Leading tyre brands today offer their tyres with a different set of features from which you can pick the tyre as per your requirement and usage. And thanks to the digital revolution different kinds of tyres are now available online and are just a click away.