When it’s time to swap out the shock absorbers that came with your 4×4, you have a choice between installing monotube shocks or twin-tube shocks. But which is right for your ride? Here’s a guide to help you make an informed decision.

One obvious difference

The big difference between monotube and twin-tube shock absorbers is the number of tubes in the shock. One tube vs two. But that doesn’t necessarily mean 2 tubes deliver twice the performance of one.

Comfort over bumps & rough terrain

Most shock absorbers achieve their dampening effect with a mixture of hydraulic fluid and pressurised gas. Monotube shocks feature a single chamber or “tube” where they keep both the fluid and gas. This provides stable, reliable support for your vehicle.

In comparison, twin-tube shocks have two separate chambers. An inner tube holds the hydraulic fluid and the outer chamber stores the gas. They also have multiple valves that control oil flow from the inner tube. When your vehicle hits a bump or pothole, fluid oil moves between the tubes to dampen the pressure placed on the shock.

Responsiveness

Responsiveness is another key. How well and how quickly do your shocks adjust to road conditions. Your suspension should be gentle on smooth road surfaces and stiffen up on rougher terrain. Twin-tube shocks get the job done by using several valves on their pistons that work independently of each other.

Monotube shocks do the same job with a single valve assembly. It distributes pressure evenly over the entire shock, putting less stress in a particular area. Monotube shocks generally offer better responsiveness than their twin tube counterparts.

Damping stability

When the damping force is stable, you’ll have a high-quality, responsive ride. Monotube shocks offer better damping than twin-tube shocks because of several aspects.

• Monotubes come with a single valve mechanism that spreads the pressure out equally. Twin-tubes, use several valves on one piston.
• The piston found in monotubes is usually much wider than the one used in twin-tubes.
• The oil capacity in monotubes is much higher than that in dual-tube shocks.
• The free-floating piston valve never lets the hydraulic fluid mix with the gas, whereas this can easily happen in twin-tube shocks.

Aeration

One of the biggest hindrances of shocks is aeration. Considering that the device contains oil and gas, there is always the chance of the two products mixing. When this happens, this usually leads to poor damping and also fading especially after a high performance or driving in rough terrain.

• Twin-tubes are more prone to aeration because of its design where there is no separation of oil and gas.

• Monotube shocks have two chambers. The upper chamber contains the oil while the lower one has the gas. A floating valve separates the two and minimises the odds of the two mixings.

Fading

Fading is a common problem that affects shocks as well as the overall suspension system. Constant pressure on the shock may lead to the performance of the accessory waning.

Fading is known to affect twin tubes more than monotube shocks. This is because of several factors, including the following:

• The surface area of the piston is much smaller.
• The shock has a smaller oil capacity.
• It is easy for the oil and gas to mix.

Monotube shocks have a larger surface area and carrying capacity. The higher amount of oil assists in dissipating heat much faster and lessens fading.

Monotube shocks are the smarter choice

While Monotube shocks may cost more than twin-tube shocks, they have an edge over twin tubes.

• They offer a better response.
• Are easier to install.
• They don’t foam.
• Lesser chance of aeration.
• They have superior damping ability.
• Offer a better ride quality.
• More durable.
• Require minimal maintenance.
• The cost, in the long run, is much lower.

Still not sure?

Don’t worry, speak to our expert team at BTA 4WD Centre – Ballina, NSW and we’ll talk you through all the benefits of each shock absorber and then recommend the best option for your 4×4 vehicle. Give us a call on (02) 66 86 6344 to get a quote and to find out more.