This is very important as it is probably the most expensive part of your trailer, it is carrying all the weight and it will also be a key point in how the trailer tows. This is a necessity on a road going trailer.
We try to sell only avonride suspension as it is probably the best on the market.
Firstly make sure you have the correct weight rating on your suspension units as they will fail if greatly overloaded. Please note the weight stated on a suspension unit is per pair. If you buy a pair of 350kg rated suspension id is 350kg per pair not each.
When setting your suspension up they need to be aligned perfectly in doing this you do not cause extra strain on your suspension units, tyres and chassis. If the wheels are not in line perfectly the wheels will travel in different directions this will rub the edge off a tyre and put excessive load on your suspension units and chassis. This is easier to do with a axle than 2 suspension units, to line pair of suspension units it is easier to clamp a straight edge ie a piece of box section to the underside of the units and another to the front or rear of the units this will keep them in line. Then bolt the plates to the units and tack to a piece box section. Remove the suspension and weld the plates you must remove as the heat from the weld can affect the rubber in the units. This box section can then be fitted square to your trailer.
On a single axle trailer set your wheels slightly back from the centre of the weight so that there is a bit of nose weight say 15-25kg please remember if you are building for towing with a small car that this can be nearly the maximum nose weight permitted and build it a little lighter, this stops the trailer trying to lift the rear of your towing vehicle which makes towing a lot safer
If you are building a twin axle or even a tri axle trailer try and set the axles under the centre of the load and the trailer wants to have slightly more weight on the front axle than the rear axle when unloaded and uncoupled.
How do you decide how many axles you need.
are fine for small trailers they are easier to manover unhitched. and keep the unladen weight of your trailer down, and the expence of purchasing or building is drastically reduced. I do not recommend only using a single axle on a trailer with a bed over 10 feet long as they get instable.
Twin & Tri axles
A twin axle trailer tows a lot straighter and more stable this is better for long lengths and high loads.
If you are building a trailer you can put the axles as close or as far as you require from each other as a rule we tend to set them the diameter of the wheel and tyre + 150mm if we are building a very long trailer ie over 16ft we increase this dimension or add a third axle as it gives the trailer more stability. The further apart the front and rear axles are the more stability you gain but also it becomes hardsr to turn the trailer as it is always tring to go in a straight line. to turn a tri axle trailer that is not coupled to a towing vehicle you need to jack the front of the trailer up on the jockey wheel until the 2 front axles are off the ground and manoveer on 3 wheels, because the wheels only want to go in a straight line twin and triaxle trailers wear tyres a lot more than a single axle trailer does. The furthe apart the front and rear axles are the more it wears tyres.
Hope this has been of some help if it has please vote it useful
Please read our other guides for other information about trailers.