Radius arms come in different builds, from steel to aluminum and billet aluminum. While steel is strong and durable but rust-prone and heavy, aluminum is corrosion-resistant, lighter, but less rigid. The billet aluminum arms are the more expensive option, but they are stronger and may last longer than the others. If you frequently ride hard on tough trails and have the cash to spare, go for radius arms made from billet aluminum.
Radius arms come in different designs, including tubed, boxed, or high-clearance. Tubed radius arms are less resistant to bending and twisting but are hollow and lightweight. This is as opposed to the heavier and bulkier "Boxed radius arms," which are more solid and sturdy for aggressive riding. High-clearance radius arms come in curved or angled forms to improve ground clearance, making them best-suited for evading obstacles. Your preferred option should depend on your terrain and riding style.
Whichever type of radius arm you choose, ensure it fits your Kawasaki Ridge model. Check if the radius arms have the correct hardware and bushings for seamless installation. It is also vital to check the radius arm's specifications and compatibility from the owner's manual before purchasing. You may estimate the correct length of the right radius arm by measuring the distance between the mounting points on your Ridge. This is even more important because the wrong radius arm length may cause issues with alignment and suspension.
The Bushings in your radius arms affect the durability and ride comfort. They may reduce the vibration and noise from the suspension, making the radius arms more flexible and mobile. This is why it is essential to only go for quality bushings made from tough material. The options are mostly the softer and quieter rubber bushings and the stiffer and more durable Polyurethane. If you want to trade off the flex and quick wear of rubber bushings for more noise and vibration, go for polyurethane bushings.
You'll need adjustable radius arms if you add lift kits and larger tires to your Kawasaki Ridge. These adjustable radius arms let you adjust their heim joints by a few inches to help fine-tune their camber and maintain fit and functionality. Unlike fixed radius arms, you can modify them to blend with different suspension settings and your driving needs/preferences. They'll need more maintenance and alignment checks, but they are more practical in the long term.