Revised Understanding of Roll Center Adjustments in RC Cars

Adjusting Front Roll Center – Pivotball Suspension

Lowering Front Roll Center:

• Front Upper Arm: Raise the position of the inner pivot pin.
• Front Lower Arm: Lower the position of the inner pivot pin.

Raising Front Roll Center:

• Front Upper Arm: Lower the position of the inner pivot pin.
• Front Lower Arm: Raise the position of the inner pivot pin.

Adjusting Front Roll Center – C-Hub Suspension

Lowering Front Roll Center:

• Inner Pivot:Front Upper Camber Link: Raise the inner mounting position on the link by adding shims.
  Front Lower Arm: Lower the position of the front lower arm’s inner pivot pin.
  
• Outer Pivot:Front Upper Camber Link: Lower the outer pivot by removing shims from between the link and the top of the C-hub.
  

Raising Front Roll Center:

• Inner Pivot:Front Upper Camber Link: Lower the inner mounting position on the link by removing shims.
  Front Lower Arm: Raise the position of the inner pivot pin.
  
• Outer Pivot:Front Upper Camber Link: Raise the outer link by adding shims between the link and the top of the C-hub.
  

Adjusting Rear Roll Center – Pivotball Suspension

Lowering Rear Roll Center:

• Inner Pivot:Rear Upper Arm: Raise the position of the inner pivot pin.
  Rear Upper Camber Link: Raise the link by adding shims.
  Rear Lower Arm: Lower the position of the inner pivot pin.
  
• Outer Pivot:Rear Upper Arm: Lower the outer pivot by removing spacers from between the arm’s outer pivot and the top of the rear hub carrier.
  Rear Upper Camber Link: Lower the link by removing shims on the top rear hub carrier.
  

Raising Rear Roll Center:

• Inner Pivot:Rear Upper Arm: Lower the position of the inner pivot pin.
  Rear Upper Camber Link: Lower the link by removing shims.
  Rear Lower Arm: Raise the position of the inner pivot pin.
  
• Outer Pivot:Rear Upper Arm: Raise the outer pivot by adding spacers between the arm’s outer pivot and the top of the rear hub carrier.
  Rear Upper Camber Link: Raise the link by adding shims on the top of the rear hub carrier.
  

Adjusting Rear Roll Center – C-Hub Suspension

Lowering Rear Roll Center:

• Inner Pivot:Rear Upper Camber Link: Raise the link by adding shims.
  Rear Lower Arm: Lower the position of the inner pivot pin.
  
• Outer Pivot:Rear Upper Camber Link: Lower the link by removing shims from between the link and the top of the rear outer end of the rear hub carrier.
  

Raising Rear Roll Center:

• Inner Pivot:Rear Upper Camber Link: Lower the link by removing shims.
  Rear Lower Arm: Raise the position of the inner pivot pin.
  
• Outer Pivot:Raise the link by adding shims between the link and the top of the rear hub carrier.
  

Conclusion

The adjustments for roll centers in RC cars are significantly different between pivotball and C-Hub suspension systems. Understanding these differences and correctly applying them is crucial for optimal performance. These adjustments should be made carefully and tested extensively to ensure they meet the desired handling characteristics on different tracks and under various conditions.