Beam
AL-KO’s range of beam axles is extensive. The axle is one of the most important components of any trailed product. It is the backbone of the carrying system and care should be taken to ensure that the appropriate style and capacity of axle are chosen.
Beam axles come in some “basic” styles and the following is an explanation of each and a guide to assist in selecting the most appropriate beam axle for your application. All axle styles are available with a wide variety of hubs and brake types.
Always ensure that the anticipated maximum loaded weight is less than the capacity of the beam axle you select!
STRAIGHT BEAM AXLES
This style of axle is the simplest and the most common.
The solid axle steel of varying section size is simply machined on each end. This style of axle is usually used on such applications as domestic trailers, boat trailers and anywhere that the height of the trailer is not a major consideration.
Included in the AL-KO range is a 60mm round hollow tube axle which is very popular in galvanised form for marine trailers and some caravan applications. The ability to use pre-galvanised tubing makes this a suitable product for applications where resistance to corrosion is needed.
OVERLAY BEAM AXLES
This type of axle is manufactured from solid medium tensile steel, but the stub axles are welded on top of the main structural beam. This has the effect of lowering the trailer height an amount equal to the distance from the centre of the beam to the centre of the stub axle. For example on a 45mm square overlay axle of 1450 kg capacity, the trailer height is lowered by 45mm compared to a straight axle of the same capacity.
Why is lowering of the trailer an advantage? The lower the trailer the better the stability, and the lower wind resistance when towing. Also a lower trailer can be an advantage for accessing.
This style of beam axle is extensively used by the caravan industry to provide a strong, reasonably priced, lower ride height axle option.
Overlay axles manufactured by AL-KO have undergone extensive evaluation of weld strength and you can be assured of the quality.
DROP BEAM AXLES
When an even lower ride height than that available from overlay axles is required, AL-KO produces a series of “drop” axles. This trailer industry term refers to an axle where there is a gap between the stub axle and the main structural beam, and this can vary up to a maximum of 100mm from the centre of the stub axle to the centre of the beam. This is achieved by using welded “drop plates” which join the main structural beam and the stub axles. This has the effect of dramatically lowering the trailer and is typically used for such applications as race car trailers and horse floats, where an easy and low access into the trailer is needed. When considering the use of a drop axle, there are more dimensional constraints than with other types of beam axles. As the drop plates need to pass the outside of the chassis or body during suspension movement, a drop axle always needs more distance from the body to the wheel centre. Whilst this can at times be a problem, talk to your AL-KO sales contact to assist with what can be made to suit your specific dimensional needs.
