22/04/2020
Tyres are a vital component of any vehicle, providing grip, steering control, and a smooth ride. However, over time, they can succumb to the elements and develop unsightly and potentially dangerous cracks. Understanding why these cracks form is the first step in preventing them and ensuring your tyres remain in optimal condition. From prolonged exposure to water and harsh weather to the simple passage of time, several factors can contribute to tyre degradation and the eventual development of cracks.
The Impact of Environmental Exposure
Tyres are constantly battling the elements. Whether parked or in motion, they are exposed to a barrage of environmental stressors that can significantly impact their integrity. Prolonged exposure to certain conditions can accelerate the wear and tear process, leading to premature cracking.
Water Damage and Its Consequences
One of the less obvious culprits behind tyre cracking is prolonged exposure to water. When tyres spend extended periods in constant rain or submerged in water, moisture can begin to permeate the rubber compound. This ingress of water can degrade the natural elasticity of the tyre. Over time, this loss of flexibility makes the rubber more susceptible to hardening and becoming brittle, setting the stage for cracks to form.
The Sun's Harsh Embrace: UV Rays
The sun, while essential for life, can be a formidable enemy to your vehicle's tyres. Ultraviolet (UV) rays, much like extreme heat and cold, can have a detrimental effect on the rubber. UV radiation actively dries out the polymers within the rubber compound. As these crucial elements dry, they lose their pliability and become brittle. This brittleness is often first observed as small cracks appearing on the sidewalls of the tyres, a clear indicator of sun damage.
The Perils of Rapid Temperature Changes
Tyres are designed to withstand a range of temperatures, but rapid and extreme fluctuations can cause significant stress. In hot weather, the polymer compounds within the tyre tend to expand, while in cold weather, they constrict. When a tyre is subjected to frequent and drastic temperature shifts, this constant cycle of expansion and contraction weakens the rubber structure. This weakening process can lead to the formation of cracks as the material struggles to cope with the repeated stress.
The Inevitable March of Time: Age and Elasticity
As with many rubber-based products, age is a significant factor in tyre degradation. Even if a tyre has seen minimal mileage, the passage of time alone will cause it to deteriorate.
Ageing Makes Tyres Brittle
The longer tyres remain on the road, the more they are exposed to wear and tear. However, even tyres stored away are not immune to the effects of time. A chemical compound is released when tyres are in motion, which helps to deter damage. While it might seem counterintuitive, taking your vehicle out for regular, short drives can actually help maintain the elasticity of your tyres and prevent them from hardening and becoming brittle. Neglected tyres, even those kept in storage, will eventually harden and lose their flexibility, making them prone to cracking.
The Crucial Role of Tyre Pressure
Maintaining the correct tyre pressure is paramount not only for fuel efficiency and handling but also for the longevity of your tyres. Both underinflation and overinflation can contribute to cracking.
The Dangers of Underinflation
Underinflated tyres are a significant cause of increased heat generation. When a tyre is not adequately pressurised, it flexes more than it should under the vehicle's weight. This increased flexing leads to greater friction between the tyre and the road surface. Consequently, the tyre overheats, which can accelerate the degradation of the rubber compounds. The heightened friction and heat can initiate and exacerbate cracking, particularly in the sidewall areas.
The Risks of Overinflation
Conversely, driving with overinflated tyres is also detrimental. Overinflated tyres have a reduced contact patch with the road, which can affect handling and braking. More importantly, excessive pressure can cause the tyre walls to swell and become rigid. This rigidity makes the rubber more susceptible to damage and increases the likelihood of cracks appearing, especially when encountering road imperfections.
Checking Your Tyre Pressure
It is essential to regularly check your tyre pressure and maintain it at the manufacturer's recommended level. You can typically find this information in your vehicle's owner's manual or on a sticker located on the driver's side doorjamb. Most modern vehicles also have tyre pressure monitoring systems (TPMS) that will alert you if the pressure is too low.
Preventative Measures and What to Look For
Preventing tyre cracks involves a combination of regular maintenance and mindful driving habits. By understanding the causes, you can take proactive steps to protect your investment.
Regular Inspections are Key
Make it a habit to visually inspect your tyres regularly. Look for any signs of cracking, especially on the sidewalls and between the tread blocks. Also, check for any unusual wear patterns, bulges, or embedded objects.
Maintain Correct Inflation
As discussed, keeping your tyres inflated to the correct pressure is one of the most effective ways to prevent premature cracking and ensure optimal performance.
Avoid Harsh Driving Conditions When Possible
While it's not always possible to avoid adverse weather, try to limit your vehicle's exposure to extreme conditions where feasible. If you live in an area with harsh winters or intense summers, ensure your tyres are suitable for those conditions.
Rotate Your Tyres
Regular tyre rotation helps to ensure even wear across all four tyres. This can extend the overall life of your tyre set and help prevent uneven stress that might lead to cracking.
Consider Tyre Age
Even if a tyre looks good, its age can be a limiting factor. Most manufacturers recommend replacing tyres that are more than six years old, regardless of tread depth. You can usually find the manufacturing date (DOT code) on the sidewall of the tyre.
Frequently Asked Questions
Q1: How often should I check my tyre pressure?
A1: It's recommended to check your tyre pressure at least once a month and before any long journeys. Temperature changes can affect pressure, so checking more frequently during seasonal shifts is a good idea.
Q2: Can a cracked tyre be repaired?
A2: Small, superficial cracks on the sidewall are generally not repairable and pose a significant safety risk. Larger or deeper cracks, especially in the tread area, may be repairable depending on their size and location, but it's always best to consult a professional tyre technician.
Q3: My tyres are old but have plenty of tread. Do I still need to replace them?
A3: Yes. The rubber compound degrades over time, becoming brittle and less safe, even if the tread depth appears sufficient. It's recommended to replace tyres that are older than six years, regardless of tread wear.
Q4: What is the DOT code on a tyre?
A4: The DOT code is a series of numbers and letters on the tyre's sidewall that provides information about its manufacturing. The last four digits indicate the week and year of manufacture (e.g., '3221' means the tyre was made in the 32nd week of 2021).
By understanding the various factors that contribute to tyre cracking and implementing preventative measures, you can significantly extend the life of your tyres and ensure a safer driving experience. Regular checks, proper inflation, and awareness of environmental factors are your best allies in maintaining tyre integrity.
If you want to read more articles similar to Why Do Tyres Crack?, you can visit the Maintenance category.