🔧 Sway Bar (Anti-Roll Bar)
A stiff wire linking the left and right suspension that resists body roll in corners — stiffer bar = less roll but less independent wheel travel.
What it actually does
A sway bar — also called an anti-roll bar — is a stiff wire linking the left and right suspension so that when one side compresses it drags the other side with it. It resists the car leaning in corners without making the suspension stiffer over bumps, which is a trick a spring alone cannot do.
In practice
Sway bars are the standard tool for balancing a car front to rear. Fitting a stiffer bar at one end reduces that end's grip in cornering, so a stiffer front bar adds understeer and a stiffer rear bar adds oversteer. Most kits supply several bar thicknesses so you can tune in small steps.
Worth knowing
Change one end at a time and only one step at a time, or you will not know which change caused what. Also check the bar moves freely in its mounts — a bar that binds behaves like a much stiffer one.
Common questions
Do I need sway bars for bashing?
Usually not. They earn their keep on high-grip surfaces where body roll is the limit; on loose dirt and jumps most people run without them or leave the softest bars fitted.
Stiffer bar front or rear for less understeer?
Softer at the front, or stiffer at the rear. Both shift the balance the same direction — start with the softer front bar because it costs you less overall grip.