Safe Towing Information
Before choosing the correct towing equipment for your vehicle it is important to determine what type of towing is going to be undertaken by the vehicle. There are three important trailer measurements that will help to find the correct towing solution:
• Aggregate Trailer Mass (ATM) This is the total mass of the laden trailer when carrying the maximum load recommended by the manufacturer. This includes the towball weight and is measured when the trailer is not coupled to the tow vehicle. The ATM will be specified by the trailer manufacturer and must not be exceeded. You can find this on the trailor id plate or by contacting the manufacturer.
• Gross Trailer Mass (GTM) This is the mass transmitted to the ground by the axle or axles of the trailer when coupled to the towing vehicle and carrying its maximum load approximately uniformly distributed over the load bearing area. The GTM will be specified by the trailer manufacturer and must not be exceeded. You can find this on the trailor id plate or by contacting the manufacturer.
• Ball Weight This is the weight imposed on the tow vehicle’s towball when a trailer is coupled to the vehicle. Ball weight is generally around 10% of the ATM. You can determine the ball weight by bringing the car and trailer into Edwardstown. Alternatively, this can be determined by taking the trailer to a weighbridge. At the weighbridge, disconnect the fully laden trailer from the tow vehicle and rest only the trailer’s draw bar (via the jockey wheel) on the scales.
A vehicle’s towing capacity is determined by the vehicle manufacturer. The manufacturer will specify:
• The maximum towing mass for the vehicle
• The maximum ball weight for the vehicle
Types of Towbars
At Southern Towbars, we stock all types of towbars.
Class 2 or Standard Towbar
Class 2 or standard towbars are suitable for lightweight towing applications, such as small 6 x 4 trailers. They are often rated for up to 1250kg. Standard towbars have 20mm thick tow tongues as opposed to a great number of other brands which only use 15mm tow tongues.
Class 3 or RL (Reese Light) Towbar
Class 3 or RL (Reese Light) Towbars are designed for heavier weight towing applications such as larger garden trailers, small boats and off road camper trailers. They are often rated up to 1600kg. These towbars come with the convenience of a removable towball tongue which can be stored when not in use. A 40mm square tube is used with a similar design to the heavy duty range. Class 3 bars give you all the benefits of a class 4 bar but are generally designed for vehicles that do not have the towing capacity of a class 4 design capacity vehicle.
Class 4 or Heavy Duty Towbar
Class 4 or heavy duty towbars are designed for heavy duty towing. They are ideal for large trailers, boats, horse floats and are also mandatory for most caravans. A majority of them are in fact rated to the vehicle manufacturer's maximum towing capacity. Class 4 or heavy duty towbars from Southern Towbars also come with a convenient TBM (towball mount) which can easily be removed from the vehicle when not in use. This helps save those shins and knee caps from being injured, plus ensuring the number plate is not obscured, avoiding unwanted fines. Another added benefit to the range of class 4 heavy duty towbars. They are also compatible with weight distribution hitches, also available from Southern Towbars.
Incorrect or Unbalanced Towing Characteristics
No matter what type of trailer you are towing, many characteristics of your vehicles performance and handling will be affected by both the trailer weight and ball weight.
When a trailer is coupled to a tow vehicle, the trailer’s total ball weight is applied onto the rear section of the vehicle between the rear axle and the towball. This will transfer the weight from the front and cause the front to lift while lowering the rear of the tow vehicle.
Also if the weight of the load in the trailer is poorly distributed, it may affect the vehicle's towing performance in the following ways:
• Poor steering and connecting grip;
• Reduced traction of front wheels;
• Incorrect wheel alignment resulting in increased tyre wear;
• Reduced braking performance;
• Increased understeer;
• Misaligned headlights.
Note that these effects become more pronounced on your vehicle as trailer size and the mass of the load increase. Maintaining a safe and driveable towing vehicle is absolutely essential.
Southern Towbars Resolution
If any of the above problems have arisen for you while towing, please contact us here at Southern Towbars and we will talk you through a number of options about the state of the art weight distribution kits.
Weight Distribution Hitches from Hayman Reese
The Weight Distribution Hitch is a device which transfers some of the load from the towbar ball to the front suspension of the towing vehicle to ensure a return to even distribution of weight, across all wheels of the tow vehicle and trailer. This even distribution of weight ensures that positive steering and braking control is maintained.
A Weight Distribution Hitch:
• Distributes towball weight to all wheels;
• Restores steering geometry;
• Reduces tyre wear;
• Ensures positive towing control;
• Improves braking;
• Reduces independent movement between trailer and vehicle;
• Reduces sway.
A Weight Distribution Hitch can be installed by Southern Towbars on most vehicles. A selection of Weight Distribution Hitches are available for ball weights up to 450kg. Weight Distribution Hitches are not suitable for use with trailers fitted with older surge or override trailer braking systems.
Weight Distribution Hitches are available from Southern Towbars in the following ball load capacity weights:
• 0 – 82 kg Ball weight = Mini Hitch
• 82 – 130 kg Ball weight = Intermediate Hitch
• 130 – 250 kg Ball weight = 550lb Kit
• 250 – 340 kg Ball weight = 750lb Kit
• 340 – 450 kg Ball Weight = 1000lb Kit
Towing a caravan, boat, horse float or heavy trailer can apply a heavy additional weight on the rear of your vehicle which is referred to as the ball weight. The weight will be carried by the rear of the wheels which will raise the front of the vehicle, thereby reducing the weight on the front wheels. As a result the vehicle will experience a reduction in steering and braking control.
The weight distributing hitch is designed to ensure a return to even distribution of weight across all wheels of the tow vehicle and trailer. This even distribution of weight ensures that positive steering and braking control is maintained. Another key point to acknowledge is that the correct weight distribution is determined by the ball weight of the van.
Heavy Duty Hitches
Southern Towbars can supply and install a range of heavy duty hitches. The key feature of the kits is the ability to adjust the weight distribution hitch to suit any vehicle and van combination inside the kits capacity.
The 550lb, 750lb and 1000lb weight distribution hitch can only be used with a hitch receiver towbar to safely tow trailers with ball weight in excess of 130kg.
Weight Distribution Hitch Adjustability
Drop Shank Availability