Much more than what the control arms bolt to, spindles just don’t get enough credit when it comes to front suspension.

A Spindle Effects Suspension Performance

The wheel spindle and hub design has a dramatic effect on how effective a suspension is; it’s the central interaction point for the control arms and the steering. Plus, the geometry built into the spindle itself can make all the difference in how a car handles and how the rest of the suspension needs to be designed to correctly balance the vehicle.

Design Geometry and Materials Matter

The spindle and hub assembly is the interface between the suspension and the wheels and tires. Without proper attention to geometry, a drop spindle to lower the stance may actually worsen the car handling.

A properly designed suspension can only do its job if the spindle has the correct geometry and can effectively transfer the load. 

Radial-X Spindle 

Redefining Best-In-Class

Our design is unique because it’s modular and configurable, rather than being a single forging locked into a specific geometry like others. This is accomplished only from professional level engineering during design phase and extremely accurate machining.

Lightweight billet spindles offer unsurpassed strength, rigidity, and versatility all in a tidy package. 

Key Features

  1. Main upright body
  2. Lower ball joint mount and steering arm
  3. Upper ball joint mount
  4. Unitized hub and wheel bearing assembly (non-serviceable) with integral wheel speed sensor

The Radial-X assembly features 4 components that can be services easily if necessary.

Vehicle Applications

Optimised for aftermarket Ford Mustang SLA conversion systems, Radial-X spindles have proven to be adaptable to a variety of applications.

  • Compatible with wide wheels and tires (315, 335, etc.)
  • Brakes rotor sizes from 13-inch and up

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Differences that Improve Performance

  • Superior stiffness and strength
  • Lower ball joint >2-inch lower than an SN-95 Mustang spindles
  • Superior wheel bearing and rotor cooling when using brake ducting
  • Mounting brackets for 3 inch hose brake ducts available
  • Exceptional steering response and cornering ability

Tuning Adjustment with Ease

  • Quick and accurate camber adjustment (shims)
  • Adjustable king pin inclination angle by changing modular upper ball joint mount
  • Adjustable Ackerman geometry using alternate modular steering arm
  • Optional bolt patters available 5×4.75 and 5×5 (5×4.5 standard)

Compatible Brake Systems



  • Stoptech ST40, 355 x 32 Rotors for 2005-2014 Mustang
  • Stoptech ST60, 355 x 32 Rotors for 2005-2014 Mustang
  • Brembo AIX Pro 4-piston (E7), 2005-2014 Mustang application 355 x 32 mm rotors
  • Brembo XB105 Calipers with both 350x34mm wide annulus rotors, 380x32mm rotors, and also 380x35mm
  • Performance Friction ZR54 355 x 32mm Grand Am endurance system
  • Baer 6R/S Calipers 14×1.25 rotors
  • Baer 6P Calipers and 14×1.25 rotors
  • Wilwood, JFZ, Sierra, and Brakeman T4 lug mount Calipers (3.5 lug mount) with 13 x 1.25″ Rotor

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