Getting a grip on tyres

Every fleet manager knows it: tyres don’t just touch the road – they touch every line on the balance sheet. Pressure, tread and temperature dictate uptime, cost per kilometre (CPK) and the difference between profit and loss. So, how should transport operators best manage their tyres? CHARLEEN CLARKE gets all the answers from Monal Naik, marketing manager at Bandag South Africa.

South Africa’s transport arteries stretch from the humid coastal corridors of KwaZulu-Natal to the high, dry plains of the Highveld and the punishing gravel of the mining belts. Across these vastly different environments, the one constant contact point between road and revenue is the tyre. How those tyres are managed – pressurised, aligned, rotated, inspected, retreaded and recorded – can make or break a fleet’s profitability.

“Tyre management isn’t a once-off check box,”  says Naik. “It’s an ongoing discipline – a shared responsibility between the driver, the workshop and the tyre partner. When that discipline is embedded in the operation, the fleet gains control of safety, costs and uptime.”

Setting pressures for South African conditions

The starting point of any tyre management regime is the air within. Pressure is simultaneously critical and invisible; its management in South Africa’s mixed topography is more complex than many operators realise. “New tyre manufacturers generally provide the maximum recommended pressure for all tyres, which we as retreaders and on-site tyre specialists adhere to,” Naik explains. “Higher loads do require higher pressure, but never more than the maximum recommended pressure.”

In practical terms, fleet engineers should start with the manufacturer’s published figures, then adjust only within safe margins for load, altitude and ambient temperature. On the coast, where air density and humidity are high, a tyre inflated to its rated maximum performs predictably. However, on the Highveld, where the atmospheric pressure is lower, Naik says that operators can consider a slightly lower tyre pressure, provided it remains within the safe operating range.

Heat also matters. Tyres expand as they warm, so the correct reading must always be taken on cold tyres. “The main considerations in tyre pressure management are regular tyre pressure checks – preferably when tyres are cold – and for pressure gauges to be calibrated. Bandag uses Bluetooth tyre probes and its ProApp to ensure pressure readings are accurate,” Naik elaborates.

It may sound simple, but under-inflation remains the most common cause of premature casing failure in South Africa – particularly on heavy trailers that run long stretches between depots. Over-inflation, on the other hand, reduces tread contact, encourages uneven wear and hardens the ride, placing unnecessary strain on suspension components. The answer lies in relentless routine.

Accuracy, calibration and accountability

Naik says the responsibility for maintaining correct tyre pressure is shared between drivers and the workshop. Drivers are the first line of defence. They see and feel the tyres daily and should be trained to recognise the warning signs of low inflation: soft sidewalls, irregular bulges or missing valve caps. “Drivers should do daily visual checks of the overall tyre condition, including tyre pressure,” Naik advises. “Tyre technicians or the workshop should check tyre pressures weekly, and especially prior to vehicles leaving the yard.”

This two-tier system – driver vigilance supported by technical verification – catches problems early. Even small aids help, while calibration closes the loop: “Ensuring valve extensions are fitted is good practice to ensure the inner tyres are also consistently pressure checked,” explains Naik. “Calibration of pressure gauges must be done regularly and is dependent on usage. Using a master gauge is recommended to cross-check pressure readings. The advantage of Bandag’s ProApp is that the Bluetooth tools can be calibrated on site with a correctly inflated tyre.”

For fleets managing hundreds of wheel positions, even slight inaccuracies can prove costly. A simple calibration log that notes the date, technician and device ID is not bureaucracy, but rather sound financial control.

Legal limits vs operational wisdom

Tyre tread depth is both a legal and operational concern. South African law, under Regulation 212 (j) of the National Road Traffic Act, specifies a minimum tread depth of under 2mm. But legality doesn’t always equal safety. “While the legal minimum tread depth in SA is 1.6mm across the tyre, a more widely safer and accepted operational threshold is 3 to 4mm, which also extends the life of casings for retreading,”  Naik explains.

He says fleets that replace tyres at 3mm tread depth or more benefit twice – reducing the risk of aquaplaning and improving casing longevity. “To ensure casings can be retreaded multiple times, fleets adopt varying tread pull-point policies. This can range from 3mm to even 8mm depending on the underfoot conditions,” he continues. Coastal and rain-prone operations, for example, often use 3mm as a pull-point, while fleets on abrasive gravel or mining routes may adopt higher thresholds to protect casing value.

Measuring wear and managing data

In the digital era, tyre data is a competitive advantage. Accurate tread measurement and trending can transform maintenance from reactive to predictive. “Using a mobile app like Bandag’s ProApp together with Bluetooth tyre probes is the best way to take tread readings,” says Naik. “This allows the tyre technician to clear any debris stuck in the grooves and visually inspect the tyre for issues such as uneven wear or tread cuts.”

These readings feed Bandag’s central database, generating detailed rubber-on-the-road reports. “It allows fleets to determine the number of tyres needing replacement based on their tyre pull-point policy,” Naik says. “Together with ProOosta – our Out-of-Service Tyre Analysis – Bandag also makes recommendations to fleets on which new tyre brands deliver the best retreadability and the optimum number of times to retread.”

Evidence-based management, he adds, is gaining traction among South African fleets that now see tyre data as a strategic tool rather than administrative clutter.

Reading the road: common wear patterns

“The most common abnormal wear patterns are irregular wear, generally caused by improper tyre inflation and mechanical issues,” says Naik. However, he adds that every road surface leaves its own mark, noting: “Chipping and chunking of tread are also common where road surfaces are poorly maintained or incorrect treads are selected for the application.”

Fleet engineers should learn to read these signatures. Feathered edges point to misalignment, while centre wear suggests over-inflation and shoulder wear indicates under-inflation or camber issues. “These can be diagnosed with route and load studies; regular vehicle alignment and maintenance are also advisable,” he recommends.

Alignment, duals and disciplined rotation

Alignment is one of the cheapest forms of tyre insurance. “This should be done at 25,000 to 35,500km for a truck tractor and twice per year for a trailer, unless fitted with hubodometers,” Naik advises. 

Axle misalignment is the critical parameter to bear in mind. “Alignment should also be checked after any mechanical work on the suspension, any signs of irregular wear or a significant impact,” he says.

For dual-fitted wheels, matching is everything. “Perfect match equals better wear and performance. A 3-mm tread depth difference between duals is the industry norm; anything above 3mm is considered a mismatch,” Naik stresses.

Mismatched tyres – whether in tread depth or diameter – create load imbalance, heat build-up and driveline stress. “Tyre size mismatching should be avoided at all costs,” Naik warns. “Different-size tyres can be very dangerous and can cause handling and stability issues, which will cause the vehicle to pull to one side.”

Regular, well-documented rotation extends tyre life and evens out wear, preventing minor variations from becoming expensive problems.

Keeping the wheels on

Loose wheel nuts continue to be a preventable cause of catastrophic wheel-offs. “Best practice for fitting and inspecting check points would be monthly tyre inspections,” Naik says. “Check points should also be inspected after a tyre rotation. To identify loose wheel nuts, ensure a minimum of four check points are used per wheel.”

Threads matter, too. “Ensure the thread on wheel nuts is not stretched by using the Bandag Thread gauge,” Naik advises. “Bandag SA recommends using ‘Wieloc’, which prevents wheels running loose or coming off and is also a deterrent for wheel theft.” Small though they seem, these plastic indicators give clear visual cues of movement, helping drivers and technicians spot issues before they escalate.

Torque, re-torque and record keeping

Torque discipline is non-negotiable. “Torque specifications are vehicle- and rim-specific,” Naik reminds operators. “A torque register must be maintained and documented. Torquing should be done after every tyre movement.”

For audits, Certificates of Fitness (CoFs) and thorough incident investigations provide crucial proof of diligence. In a litigious environment, paperwork can be as valuable as the torque wrench itself.

Retreading for value, not just cost

If tyre management has an economic heart, it’s in the casing. Retreading has long been a cornerstone of South African fleet management, but the quality of casings has declined. “In South Africa, retreading is a well-accepted discipline and forms a key part of any major fleet’s tyre management plan, but the national average retreadability in SA has seen a 25% decline over the past decade, driven mainly by the increase in low-cost imports,” Naik elaborates.

He is frank about the consequences: “These ‘disposable tyres’ offer not only lower retreadability, but also less total mileage and uptime. Buying premium new tyres that offer retreadability and mileage is still the most viable solution for SA transporters.”

Some of Bandag’s blue-chip fleets, he adds, are achieving “double the national average for retreadability”. Their formula is simple: rigorous inspection, disciplined repair policies and consistent data analysis. “Selecting the right new tyre, monthly tyre inspections and scrap data analysis – all of which the right retread partner provides – help fleets achieve this.”

Repair or scrap? Know the line

Tyre damage is inevitable, but unsafe repairs should never be. “Bandag has strict policies on tyre repairs, safety and retreading,” Naik emphasises. “We do not do salvaging of tyres, while we also limit the type and number of repairs allowed per tyre.”

Repair limits safeguard both safety and reputation. Penetrations in the crown area may be repairable; sidewall or shoulder damage usually means a tyre must be scrapped. Each repair should be logged by serial number and reviewed at the retread stage.

Measuring success: the KPIs that count

Which key performance indicators (KPIs) truly reveal whether tyre management is working? “At Bandag we use the ‘Secret Seven’ approach: a focus on air pressure, overloading, tyre selection, tyre matching, tyre pull-point, vehicle alignment and tyre breakdowns,” reveals Naik.

“All these factors play a major role in managing fleet CPK and form part of our proactive approach. We believe that with the correct focus on the ‘Secret Seven’, fleets can reduce tyre operating costs by up to 30%,” he continues. Scrap tyre analysis completes the loop. “It’s a critical tool that helps identify trends and take corrective action where possible,” notes Naik.

A well-managed tyre programme thus becomes a continuous data engine – every worn casing tells a story, and every story guides the next purchasing decision.

People, training and culture

Naik believes people make or break the system – behind every tyre policy there is someone with a gauge or a steering wheel. “Bandag offers driver training as well as on-site posters to aid both drivers and the workshop in making correct tyre decisions,” he says. “Driver training includes advising drivers to visually inspect tyres prior to departure, avoid potholes and not kerb, but also to report issues to the tyre bay.”

Creating a culture where tyre care is everyone’s job yields measurable results. Pre-trip checks, awareness of wheel-nut indicators, valve cap discipline and accurate reporting all extend tyre life and prevent roadside failures.

Tyres as an investment, not an expense

Tyre management, when properly executed, is neither glamorous nor optional. It is an engineering discipline, a safety imperative and an environmental responsibility rolled into one.

South African fleets operate in one of the most demanding transport environments in the world – yet those who master tyre care consistently outperform those who don’t.

As Naik concludes: “With the correct focus, consistent measurement and the right partnerships, South African fleets can extend tyre life, reduce cost and improve uptime. Tyres aren’t just an expense – they’re an investment in every kilometre that keeps the economy moving.”