ACKERMANN ANGLEUpdated 2 months ago

Ackermann Angle – What It Is and Why It Matters

When you turn your steering wheel, your front tires don’t turn at the same angle. That’s by design. The Ackermann angle accounts for the fact that the inside tire needs to follow a tighter arc than the outside tire during a turn. This difference in angles is called Ackermann steering geometry.

If the geometry is correct, both tires roll smoothly through the turn, minimizing scrub (tire dragging or hopping). But if the Ackermann angle is off—due to poor axle geometry or steering knuckle design—you’ll see excessive tire wear, inefficient steering, and loss of traction in technical or high-load situations.

In our axles, especially when custom width and steering angles come into play, we carefully engineer the position of the steering arms and knuckle pivot points to preserve or improve Ackermann geometry. This is particularly important when running larger tires or custom wheel offsets.

Scrub Radius – The Steering Feel and Load Factor

Scrub radius is the distance between where the steering axis (an imaginary line drawn through the upper and lower ball joints or kingpins) intersects the ground and where the tire centerline hits the ground.

In simple terms, it affects:

• How your steering feels (heavy or light)
• How stable your rig is under braking
• How well your steering handles bumps and terrain irregularities

Too much scrub radius leads to excessive steering effort and poor feedback. It can also increase wear on ball joints, tie rods, and wheel bearings. On the other hand, too little can lead to vague steering response.

Dynatrac’s Wide-Track Axles – Designed for the Right Scrub Radius

When we designed our Dynatrac ProRock XD60 axles with wide-track configurations, we did it for more than just clearance or articulation. The wider stance allows for:

• Improved scrub radius geometry—especially important when running deep-offset wheels or larger tires
• Reduced steering effort and improved return-to-center characteristics
• Better alignment of the steering axis to the tire’s contact patch, reducing mechanical leverage against the ball joints and unit bearings

With our wide-track setups, we also ensure that Ackermann geometry stays intact, even when wheel mounting surfaces are pushed outward. We accomplish this by repositioning the steering arm length and angle on our heavy-duty knuckles to keep turning angles in check.