4X4
Moderator
Most people who have a four-wheel drive own two sets of tyres, and the advantages of this have been discussed in an earlier article. If you are in a position to purchase a second set of rims, I suggest you buy steel rims. Not because they are cheaper, but because they are stronger (for serious 4WDriving). Yes, steel rims can bend, but if you are unfortunate enough to damage one, you can usually make a bush repair to get you home. Alloy rims can crack or shatter, leaving you with no alternative other than your spare. Keep your alloy rims for the road.
When fitting aftermarket rims to your four-wheel drive, careful consideration must be given to the wheel offset. Offset is the measurement in millimetres from the centre line of the wheel to the wheel mounting face. If the offset of the wheel is not correct for the vehicle, the handling may be adversely affected. When the width of the wheel changes, the offset also changes numerically. If the offset were to stay the same, while you added width, the additional width would be split evenly between the inside and outside. For most vehicles, this will not work, as fouling of brake callipers or steering components will occur. If possible, use the original steel rims that came with your vehicle.
Wheel offset can be one of three types.
Zero Offset
The hub-mounting surface is even with the centreline of the wheel.
Positive
The hub mounting surface is toward the outside of the wheels centreline. Most original rims these days run a positive offset. This in effect, tucks the wheel inside the guards. Although illegal, some people fit spacers between the wheel and hub to change to a negative offset.
Negative
The hub mounting surface is toward the inside of the wheels centreline. "Deep dish" wheels are typically of a negative offset. Most aftermarket rims run a negative offset. Manufacturers do this to achieve a universal product where one size fits all, because negative offset will not foul on steering or brake callipers. The problem with negative offset is that it increases the load put on wheel bearings. Fitting aggressive tyres and lifting wheels (which is unavoidable while 4WDriving), compounds the problem. Negative offset can also move the tyre outside of the vehicles guard, necessitating an added cost for the fitment of wheel arch flairs. There is one advantage of having tyres outside the guards, if you are close to a rut or rock, the tyres can actually hold the vehicle off the rut or rock and prevent panel damage.
When fitting aftermarket rims to your four-wheel drive, careful consideration must be given to the wheel offset. Offset is the measurement in millimetres from the centre line of the wheel to the wheel mounting face. If the offset of the wheel is not correct for the vehicle, the handling may be adversely affected. When the width of the wheel changes, the offset also changes numerically. If the offset were to stay the same, while you added width, the additional width would be split evenly between the inside and outside. For most vehicles, this will not work, as fouling of brake callipers or steering components will occur. If possible, use the original steel rims that came with your vehicle.
Wheel offset can be one of three types.
Zero Offset
The hub-mounting surface is even with the centreline of the wheel.
Positive
The hub mounting surface is toward the outside of the wheels centreline. Most original rims these days run a positive offset. This in effect, tucks the wheel inside the guards. Although illegal, some people fit spacers between the wheel and hub to change to a negative offset.
Negative
The hub mounting surface is toward the inside of the wheels centreline. "Deep dish" wheels are typically of a negative offset. Most aftermarket rims run a negative offset. Manufacturers do this to achieve a universal product where one size fits all, because negative offset will not foul on steering or brake callipers. The problem with negative offset is that it increases the load put on wheel bearings. Fitting aggressive tyres and lifting wheels (which is unavoidable while 4WDriving), compounds the problem. Negative offset can also move the tyre outside of the vehicles guard, necessitating an added cost for the fitment of wheel arch flairs. There is one advantage of having tyres outside the guards, if you are close to a rut or rock, the tyres can actually hold the vehicle off the rut or rock and prevent panel damage.