Wheel chains are designed to allow a vehicle to climb a gradient that’s beyond the grip level of the tyres. In countries other than Australia, wheel chains are normally fitted to snow tyres, not summer tyres. Australian regulations call for all vehicles in Victoria, and 2WDs in NSW, to carry wheel chains that can be correctly fitted to your tyres when required.
The ‘Owners manual’ of your vehicle will detail what wheel and tyre combinations are approved for the fitting of wheel chains. The safety of any vehicle, especially the braking performance, is compromised if wheel chains are fitted to summer tyres and if wheel chains are used on a ‘bare’ road that is free of snow and ice.
Wheel chains on summer tyres
Fitted to front wheels
Wheel chains fitted to summer tyres on the front wheels of a 2WD or AWD will increase traction for take off and driving but can not assist with lateral stability. Because of the inadequate grip on the rear tyres the vehicle will oversteer and when braking the ABS system will be activated, further increasing the stopping distance. The problems are always worse when driving down hill than up hill.
Fitted to rear wheels
Wheel chains fitted to summer tyres on the rear wheels of a 2WD or AWD will increase traction for take off and driving but can not assist with steering or lateral stability. Because of inadequate grip on the front tyres the vehicle will not ‘turn in’, it will understeer and when braking the ABS system will be activated, further increasing the stopping distance. Again the problems are always worse when driving down hill than up hill.
Some concerns about chains on summer tyres
There are issues when diamond pattern snow chain systems are used on high performance 2WD or AWD ‘summer’ tyres. On summer tyres snow chains will grip to the snow/ice but the tyre can slip or spin the chain even when they are correctly tensioned on to the tyre. The problem is worse when the vehicle has been parked at the resort because the low ambient temperature makes the tyres harder and therefore has even less grip to the chain.
The issue is compounded by the camber of the road, the weight and torque of the vehicle and the amount of tread on the tyre. The tread compound in Nokian snow tyres, however, is designed to remain flexible in extremely cold conditions, making wheel chains on snow tyres more effective.
Wheel chains on snow tyres
For wheel chains to work effectively they must be able to rely on the tread of the tyre for grip to help prevent the wheel from spinning inside the chain or the chain ‘rolling’ off the tyre due to the lateral loads when cornering. Given the superior tread on snow tyres, it’s commonplace in countries other than Australia for the wheel chains to be fitted to snow tyres, not summer tyres.
Here in Australia, it makes just as much sense to fit them to snow tyres. Wheel chains need to have firm compacted snow or ice to penetrate to provide the maximum amount of traction. Traction is often lost when the snow and/or ice begins to break up or melts and wheel spin is experienced. In certain situations, i.e. on a ‘bare’ road, the vehicle can slide on the wheel chains. In order for wheel chains to work effectively they must penetrate in to a compacted surface.