High-clearance Hybrid Radius Arms
Posted: 05 May 2025 07:07
In the last few years a higher proportion of guys have been running larger tires.
There are a number of clearance issues when running tires of 35" and larger. Ideally the axle needs to be moved a bit further forward to clear the rear edges of the front arches. This is normally done by placing spacers between the radius arm and the bush at the chassis end, but this possibly places greater stresses on the pin section of the radius arm.
Furthermore the tires rub on the outside edge of the radius arms, reducing the car's turning circle.
Over and above this, the radius arm setup is already the limiting factor in flex of the front axle.
Some Australian companies manufacture and sell what they call "hybrid arms", which move away from the double top-hat style bushes at the chassis end and replace them with the same style bushes as are at the front end of the arm. This is probably significantly stronger, but require "drop boxes" to lower the pivot point below the chassis. This has a number of advantages on a lifted car as it reduces the angle of the arms, making them ride bumps much better as well as allowing the arms to be slightly longer which increases flex, but they do hang down from the chassis quite a lot.
There are a number of clearance issues when running tires of 35" and larger. Ideally the axle needs to be moved a bit further forward to clear the rear edges of the front arches. This is normally done by placing spacers between the radius arm and the bush at the chassis end, but this possibly places greater stresses on the pin section of the radius arm.
Furthermore the tires rub on the outside edge of the radius arms, reducing the car's turning circle.
Over and above this, the radius arm setup is already the limiting factor in flex of the front axle.
Some Australian companies manufacture and sell what they call "hybrid arms", which move away from the double top-hat style bushes at the chassis end and replace them with the same style bushes as are at the front end of the arm. This is probably significantly stronger, but require "drop boxes" to lower the pivot point below the chassis. This has a number of advantages on a lifted car as it reduces the angle of the arms, making them ride bumps much better as well as allowing the arms to be slightly longer which increases flex, but they do hang down from the chassis quite a lot.