Vehicles can have a variety of different types of suspension. For example, it could be trailing arm (or semi-trailing), leaf spring, multi-link, or double wishbone. They all have the same goal in mind though; ensuring a more comfortable, more responsive, and safer drive. Sometimes this comes down to what materials you use, including different types of ERW tubes. We want to look at that here, focusing on trailing arms in particular.
What is it?
In a basic sense, what you have with a trailing arm suspension is a link (or arm) between the chassis and the axle or wheels. They are horizontal perpendicular to the axle and connecting with a pivot joint. Some designs have multiple arms or links, especially for live axles. You can also have independent rear suspension that uses a similar idea, with semi-trailing arms.
The trailing arm suspension means the links or arms move to account for irregularities in the road. This can provide shock absorption. Some aircraft also have this style of suspension in their landing gear.
What to use?
The crucial thing here is the arms or links have to be strong and durable because they are such a crucial part of the suspension. Manufacturers therefore have to be careful when they decide what to use. Generally they will select products with a very long lifespan so people don’t need to worry about suspension failure.
Metal tubing is generally the best option because it is lightweight but strong, sturdy, and durable. It can outperform solid rods in the majority of situations. However, you need to be careful here. Some people will argue between choosing ERW tubes or seamless.
Typically, cold drawn welded (CDW) is best. It is a version of ERW with cold drawing to finish the dimensions. It can offer close tolerances and great mechanical properties, making it ideal for automotive components and shock absorbers.
The alternative is cold drawn seamless (CDS) tube. It doesn’t have a weld seam because it is made by drawing a solid bar of material over a mandrel to make rough tubes. There can then be finishing to get the final dimensions. However, CDS tends to be more for machine parts rather than vehicles.
Symptoms to watch out for
If you have a vehicle with trailing arm suspension, there are a few signs to watch out for. They can indicate there is an issue. However, keep in mind that the arms or links aren’t usually the issue, especially if you choose high quality ERW tubes. Instead, the problems tend to be because bushings are worn out.
One thing you may notice is a clunking noise. There should never been a noise from the suspension. The louder it is, the more important it is to get a professional to have a look.
Another thing you may find is the vehicle won’t stay in a straight line. If the bushings or links are broken the rear axle may be able to move independently. As a result, the vehicle may sway when you are driving.
It is also a good idea to keep an eye on the height of the vehicle. When the suspension is in good condition vehicles should be relatively level. If one side is massively lower than the other, it is likely there is a problem with the bushings or arms.
Finally, an issue can mean the suspension is not in proper alignment. It can result in excessive tyre wear on one side. Keep an eye on the tyres and look for any signs that they are wearing quicker than they should.
Do you want to order ERW tubes?
Union Steel Tubes is one of the UK’s top experts when it comes to ERW tubing. Our range is massive, including different shapes and sizes. We can then offer a choice of finishes and cut the tube to any length. This can even include shorter pieces for a variety of parts and components.
So, if you ever need ERW tubes, we can cater for you needs. Contact us to find out more.
