6-Pin Knock-Off Wheel Hubs

The difference between 6-pin and 5-pin hubs mainly comes from history, engineering, and cost.

1️⃣ Original Cobras: why 6 pins?

On factory-built Shelby Cobras (1962–1967), especially the 289 and 427 models, Shelby used 6-pin knock-off hubs for several reasons:

a) Strength and safety

• Cobras produced a lot of torque (especially the 427).

• 6 pins :

  • better load distribution

  • less shear stress on each pin

  • improved durability under racing conditions

Shelby clearly had competition in mind (SCCA, Le Mans, etc.).

b) British racing competition standard

• Cobras used:

  • Halibrand wheels

  • British-style racing hubs

• At the time, most British race cars (Jaguar, Aston Martin, Lola, etc.) used 6-pin hubs.

👉 The 6-pin system was the high-end racing standard, not a marketing choice.

c) Ultra-fast wheel changes

• The central knock-off system allowed:
  
  

  • very fast wheel removal

  • high reliability under intensive use

• The 6-pin setup handled better:
  
  

  • impacts

  • heavy braking

  • high lateral loads

2️⃣ Why are 90% of replicas built with 5-lug hubs?

This is where modern compromise comes into play.

a) Cost

A true 6-pin setup requires:

• hubs

• dedicated wheels

• adapters

• knock-off spinners

➡️ This becomes very expensive (often €4,000 to €6,000 or more).

A 5-lug setup is:

• far cheaper

• compatible with standard wheels

b) Mechanical simplicity

• Modern suspension and drivetrain platforms (Mustang, Jaguar, Sierra, etc.) are natively 5-lug.

• Converting to 6 pins requires:

  • custom-machined parts

  • very tight tolerances

  • more complex installation

👉 Replica manufacturers prioritize road reliability, not racing.

c) Road use, not competition

• About 90% of replicas:

  • are driven sparingly

  • never see the track

• A 5-lug system is more than sufficient for 500+ hp in road use.

• The advantage of 6 pins becomes symbolic rather than functional.

d) Homologation & insurance

In some countries:

• 5-lug setups are easier to:

  • homologate

  • insure

  • pass inspections

• 6-pin hubs are sometimes considered:

“non-standard competition equipment”

3️⃣ Why do some high-end replicas still use 6-pin hubs?

Because they aim for historical accuracy:

• ERA

• CSX Continuation

• Kirkham

• Backdraft (competition option)

• Superformance (FIA specification)

👉 These manufacturers:

• reproduce the original geometry

• accept the higher cost

• cater to purists

👉 The 6-pin system is not “better” for road use, but it is:

• more authentic

• more race-oriented

• more faithful to the Shelby spirit