Can the plans be modified?

Modifications can be made to our trailer plans designs; however, some conditions apply. A chassis could generally be shortened (in length or width) but not extended (longer or wider). Increasing length or width usually requires bigger/stronger sections. Drawbars can be shortened, but not extended. Drawbar sections should not be reduced to smaller sections or thinner wall thicknesses. Use the material grade specified, or better, for drawbars.

Our designs are such that the drawbar and chassis frame form the core structure of the design. Items such as side panels, headboards, ramps, tie-down rails, upper frames etc. generally do not affect trailer compliance and can in most cases be added, modified or removed without adversely affecting compliance.

Axle and suspension setups can be adjusted too if required. For example, fitting a tri-axle group instead of a tandem group (or vice versa) as specified in our plans can be done. The centre of the single axle, tandem or tri-axle group, should be located in the same position. Legally, the centre of the axle group must be on or behind the centre of the load area. Our axle positions are in most cases located on a 60/40 split of the load area front/rear. With a uniformly distributed load this should give a ball weight of approximately 10% at maximum ATM.

Similarly, you can choose to replace the beam axle & leaf spring style suspension with rubber torsion or independent suspension style systems. Most after-market suspension systems can be fitted to our chassis. The suspension manufacturer will usually provide installation instructions. The cross-member size supporting independent suspension trailing arms would normally be the same (or better) as the drawbar section specified in our plan. Centre of the axle/group would be as per plan or adjusted as described above.

Wheels & tyres may be changed, although consideration must be given to clearance, overall width and brake efficiency. The sum of load ratings of axle(s), suspension, bearings & brakes must be sufficient for the load carried by the axle or axle group.

Materials specified in our plans is generally steel RHS grade C350L0. Sheet metal is C250L0 unless otherwise specified. Changes in chassis or drawbar materials, for example using aluminium or alternate grade steels, will affect compliance and should be avoided.