Gary Banister is National Account Manager at Hitachi Capital Vehicle Solutions. As part of his job, he advises our customers on road safety. Here he explains why, and how, fleets ought to check their tyres.
How can van and truck fleet operators better look after their tyres?
It is imperative that drivers undertake daily walk-round checks before they get into their vehicles. These checks should take in many parts of the vehicle.
Among the most important parts to be checked are the tyres. A driver should check their condition, including their pressure and the depth of their treads. They should be looking for any deep cuts or damage to the tyre walls, ensuring there is no cord visible, and that all wheel nuts are secure and tightened properly. Any irregular wear on the tyres should also be checked. If anything is not to the required standard, it will severely affect the life and durability of your tyres – and, therefore, the safety of your vehicle.
Drivers should also make sure, along with their managers, that they have the correct tyre for the driving conditions they’ll face.
It is also imperative that drivers know whom they should tell if their tyres are damaged or defective in any way.
At what level of tread should you replace tyres on commercial vehicles?
The law states that trucks weighing over 3,500kg must have a minimum of 1mm of tread across the central three-quarters of the tyre around its entire circumference. For vans under 3,500kg, the minimum is 1.6mm. The decision on when to replace tyres on commercial vehicles rests with the operator. The majority of our customers choose to replace tyres when they reach 2mm, and some even do so at 3mm.
Does wheel alignment matter?
Wheel alignment is a complex but very important area. It depends on a range of factors: vehicle type, operation and load. Getting it wrong can cause tyres – as well as mechanical parts of the vehicle – to wear out faster. It can also affect handling and safety whilst driving.
The three aspects of wheel alignment are camber, toe and caster:
- Camber is the vertical tilt of the tyres: positive when the top is further out than the bottom, negative when the top is closer in. Most operators prefer a positive camber angled slightly towards the near side, which helps to account for the crown of the road.
- Toe-in is where the wheels point towards each other at the front, and toe-out is where they point away from each other. Avoiding excessive toe is the most important way to preserve your tyres. Excessive toe-out will quickly wear the inside edges of the tyre, while toe-in will wear the outside of the tread.
- Caster is the angle at which the steering pivot meets the wheel, as viewed from the side. Although caster is not so important for tyre wear, it does affect the handling of the vehicle. Positive caster (where the steering pivot tilts backwards at the top) is best for keeping the vehicle stable in a straight line, and for straightening out after turning.
It’s also important to make sure the vehicle’s axles are parallel. If they’re not, the vehicle may pull to one side, causing handling problems and excessive tyre wear.
What is your approach to re-treading tyres on commercial vehicles?
At Hitachi Capital Vehicle Solutions, we run Michelin tyres, which allows us to re-tread and re-groove them as necessary while maintaining high performance.
Re-treading (putting new rubber on a used carcass) and re-grooving (cutting a new tread into used tyres) are environmentally friendly ways of helping our customers keep their costs down. Instead of fitting brand new tyres, they enable us to use the same set of tyres for much longer, without compromising handling, safety or fuel economy.