RC Steering Throw Symmetry Explained
What Is Steering Throw Symmetry
Steering Throw Symmetry refers to having equal steering travel (or “throw”) to the left and right sides of your RC car.
In simple terms, it means:
• The wheels turn the same angle left as they do right
• The servo moves the same distance in both directions
• The car responds equally when turning in either direction
Perfect Steering Throw Symmetry ensures that your car behaves consistently whether you’re entering a left-hand corner or a right-hand corner.
How Does Steering Throw Symmetry Affect Your Car?
Steering Throw Symmetry directly affects balance, consistency and driver confidence.
1. Corner Consistency
If your Steering Throw Symmetry is off:
• One direction may have more steering angle than the other
• The car may turn tighter to one direction
• Lap times become inconsistent
With proper Steering Throw Symmetry:
• Left and right turns feel identical
• The car is easier to place on the racing line
2. Steering Feel and Predictability
Uneven Steering Throw Symmetry can make the car feel:
• Aggressive in one direction
• Lazy or understeery in the other
Balanced Steering Throw Symmetry gives:
• Predictable steering input
• Smooth transitions through corners
3. Stability Under Braking and Acceleration
When Steering Throw Symmetry is uneven:
• The car may pull slightly under braking
• It may drift off-line under throttle
Correct Steering Throw Symmetry helps the car track straight and stay stable.
4. Driver Confidence
Even small differences in Steering Throw Symmetry can:
• Make the car feel “off”
• Force you to compensate subconsciously
When it’s correct, the car feels neutral and easy to drive.
How Do You Change Steering Throw Symmetry?
Adjusting Steering Throw Symmetry can be done through your radio, servo setup or mechanical components.
1. Radio (EPA / End Point Adjustment)
This is the easiest and most common method.
• Use your transmitter’s EPA settings
• Adjust left and right steering endpoints independently
• Match the steering angle visually or with a setup gauge
Tip: Turn the wheels fully left and right and compare angles from the front of the car.
2. Sub-Trim and Centering
Before adjusting endpoints:
• Make sure your servo is centered
• Ensure the wheels are straight at neutral
• Use sub-trim only for fine adjustments
3. Servo Horn Position
If the servo horn is not centered (or, in some cases, offset properly), one direction may have more travel than the other.
Fix:
• Re-install the servo horn as close to 90° as possible
• Re-center the system before fine-tuning
4. Steering Linkages
Unequal linkage geometry can cause asymmetry.
Check:
• Left and right steering links are equal length
• Bellcrank system is centered
• No binding on one side
5. Mechanical Limits
Sometimes the chassis limits steering differently on each side due to:
• Suspension interference
• CVD or driveshaft angles
• Steering stops
You may need to:
• Adjust steering stops
• Modify endpoints to match the maximum usable angle
When To Change Steering Throw Symmetry
You should check or adjust Steering Throw Symmetry in these situations:
1. After Building or Rebuilding Your Car
• New builds often have uneven linkages
• Servo horns may not be perfectly aligned
2. After Crashes
• Impacts can bend steering components
• Link lengths may shift slightly
3. When the Car Turns Better One Direction
If you notice:
• Tighter turning left than right (or vice versa)
• Different steering feel in corners
This is a clear sign Steering Throw Symmetry needs adjustment.
4. Before Competitive Racing
Consistency matters more than maximum steering:
• Balanced steering improves lap times
• Reduces driver error
5. After Changing Steering Components
Any changes to the following can affect Steering Throw Symmetry:
• Servo
• Bellcranks
• Steering rack
• Turnbuckles
What to Check After Changing Steering Throw Symmetry
After adjusting Steering Throw Symmetry, go through this checklist:
1. Steering Center
• Ensure the car tracks straight with no input
• Re-check trim if needed
2. Equal Steering Angle
• Confirm both sides reach similar angles
• Avoid overdriving one side into binding
3. Binding or Resistance
• Turn wheels lock-to-lock
• Check for smooth movement both directions
4. Servo Strain
• Listen for servo buzzing at full lock
• Reduce EPA if necessary to prevent damage
5. On-Track Testing
• Run consistent laps
• Compare left-vs-right corner performance
• Make small adjustments if needed
6. Tire Wear
Uneven Steering Throw Symmetry can cause uneven tire wear side-to-side. Monitor tires after a run to confirm balance.
FAQ
Q: What is the easiest way to set Steering Throw Symmetry?
A: Use your transmitter’s EPA settings and visually match left and right steering angles.
Q: Should Steering Throw Symmetry always be perfectly equal?
A: For most applications, yes. However, in rare cases, racers may slightly bias steering for track layout, but this is advanced tuning.
Q: Can Steering Throw Symmetry affect straight-line tracking?
A: Yes. Poor Steering Throw Symmetry can cause the car to pull slightly under throttle or braking.
Q: Do I need setup tools to adjust Steering Throw Symmetry?
A: Not necessarily. You can do it visually, but a setup gauge improves accuracy.
Q: What happens if I have too much steering on one side?
A: The car may over-rotate in that direction. It can also feel inconsistent and unpredictable.
Q: Does Steering Throw Symmetry affect both on-road and off-road cars?
A: Yes. It’s important for all RC vehicles, though it’s more noticeable on high-grip surfaces like carpet or asphalt.
Related Tuning Adjustments
To get the most out of this setup change, review these related guides:
• Ackermann
• Axles – Inline and Trailing
• Toe In / Toe Out
Back to the RC Suspension Tuning Guide.
