Demystifying Radius Arms: Everything You Need to Know

Posted By: Superior Engineering Published: 12/07/2024 Times Read: 579 Comments: 0

Demystifying Radius Arms: Everything You Need to Know

Here at Superior Engineering HQ, we thought it was about time to do a little deep dive into the world of radius arms - those magic suspension components that keep our wheels on the ground and our rides smooth.

But first, let's talk about castor. No, not the oil you put in your car — castor is all about steering angles. Put simply, castor refers to the tilt of the steering axis when you're viewing it from the side. Positive castor means the wheel is in front of the load, while negative castor means it's the other way around. Got it? Great!

If your castor is not adjusted properly, your vehicle might start pulling side to side like a stubborn mule. If one side has less positive caster than the other, your rig will have a favourite side to lean toward. And if the caster is too negative or too positive, your steering will feel wonky, and your wheels might start to play up when you hit bumps. Keeping your vehicle's castor angles in check is a key factor for optimum stability, performance, and longevity. When a vehicle is lifted, it changes its geometry. One of the effects of this is that it “rolls” the diff. Castor correction is one way to fix this issue on your lifted vehicle, and keep everything running smoothly.

How to Correct Castor

First up, we've got the castor correction bushes. These little fellas work like a charm, and they won't break the bank either, starting at just $220. They slide right into the radius arms, but not all bushes are created equal. Our Superior Engineering bushes are top-notch, with voids that let them flex without causing trouble.

Next on the list, we've got castor plates. They're like the DIY fix for bigger lifts (4-7 inches). They might be cheaper, around $190, but they won't give you the precision you're looking for, and your on-road ride might feel a bit lackluster.

Now, brace yourselves for the drop boxes — a creative way to get things just right. By dropping the rear of the radius arm, you correct the castor and get a smoother ride, just like the pin-style arms. Expect to pay around $490 for a drop box to be used with OEM radius arms.

Replacing Your Radius Arm for Castor Correction

Installing new radius arms is the most effective way to ensure proper castor alignment and keep your 4x4 performing at its best after a lift. By increasing the distance between your wheel hub mounting point and frame mount point, they help adjust castor angles to keep all four tires in contact with the road at all times.

What Radius Arms Are There?

Alright, time to meet our cast (or should we say… castor) of characters — the different types of radius arms we've got on offer:

Pin Style Radius Arms

These are the classics, found in Nissan or Land Rovers. They've got a "pin" style at the rear and sport a "mushroom bush." Old-school cool, if you ask us.

Eye Style Radius Arms

Toyota lovers, this one's for you! Eye style radius arms with their eye-style bushings give you more flex and less bush wear. Go wild!

Hybrid Radius Arms

Best of both worlds! These arms come with an eye style rear bush, ditching the pin, and they run a drop box for some extra magic. The best of innovation and tradition.

Superflex Radius Arms

Superflex Radius Arms are all about that extra travel and flex. By changing the passenger side mount, these arms will have you conquering obstacles like a boss.

Hybrid Superflex Arm

Take the Superflex and add a drop box in the rear, and you've got yourself a hybrid that's ready to take on anything.

Hyperflex Radius Arms

Are you ready to go all-out? Superflex mounts on both sides and drop boxes on the rear — this combo is a beast on those rough off-road tracks!

5 Link Suspension

The ultimate off-road dream. This setup combines a control arm and radius arm and works with all lift heights to give you unparalleled flex and off-road ability. Hybrid 5 Link combines our unbreakable hybrid dropbox radius arms with a heavy-duty adjustable upper control arm into a unique system with unrivalled travel. Superior’s patented design allows the fitment of your factory sway bar and ABS models are predrilled for sensor wires.

No matter which type of radius arm you choose, rest assured, we've got you covered. All Superior Arms come with a lifetime warranty against bending. Made from Bisalloy 80, they're as tough as nails and won't let you down.

Our helpful crew at Superior Engineering can help you select the right radius arm to help you hit the road (or off-road!) with the right castor angles, taking into consideration the make and model of your car, your budget and how you use your vehicle. Get in touch and contact us here, or via live chat.