๐ŸŽ๏ธ RC Tuner

Module 2 ยท The Tire's Edge

๐Ÿ“ Camber & Toe

The two angles that define your tire's contact patch. Master these and you master grip.

Lesson 1 of 4

๐Ÿ”ป Camber โ€” Tire Lean Angle

Negative camber keeps the tire flat during cornering roll. Too much loses straight-line grip.

Camber is the tire's angle when viewed from the front. Negative = top leans in, positive = top leans out. Touring cars ALWAYS run negative camber.

As the car corners, weight transfers OUT. The tire rolls on its sidewall. Negative camber compensates โ€” it keeps the tire FLAT on the ground during the corner, maximizing contact patch.

Typical values:

Front: -1.5ยฐ to -2.5ยฐ ยท Rear: -1.0ยฐ to -2.0ยฐ

More front camber = more initial bite (but less straight-line grip). Less rear camber = more stability on power.

Visual โ€” how camber changes the contact patch in corners

๐Ÿ”ด
0ยฐ Camber
Max straight-line grip
Corner = tire rolls, sidewall takes load
๐ŸŸก
-2ยฐ Camber
Balanced โ€” tire lands flat in corners
Slight straight-line loss
๐ŸŸข
-3.5ยฐ Camber
Max corner grip
Significant straight-line loss, inner edge wears
โš ๏ธ Critical insight

The camber you SET at the workbench is NOT the camber in the corner.

As suspension compresses, camber changes (more negative). This is called camber gain โ€” we cover it in Module 5. What you measure statically is just the starting point.

How to set camber

  1. Set ride height FIRST
  2. Car on flat board, wheels straight ahead
  3. Place camber gauge against hub face (or tire sidewall for quick check)
  4. Adjust camber link length (turnbuckle) until you hit target
  5. Re-check after adjustments โ€” turnbuckles can shift
Lesson 2 of 4

๐Ÿ‘‰ Toe โ€” Steering Tendency

Toe controls how eagerly the car wants to turn. It also creates drag โ€” the #1 tire wear factor.

Toe is the angle viewed from the top. Toe-out = front of tires point outward (car wants to steer out). Toe-in = front of tires point inward (car wants to go straight).

Front toe (almost always toe-out):

0.5ยฐ โ€“ 2.0ยฐ toe-out on front = sharper turn-in, more responsive. Too much = nervous on straights.

Rear toe (almost always toe-in):

2.0ยฐ โ€“ 3.5ยฐ toe-in on rear = stable under power, predictable exit. Too much = massive drag, hot motor.

Toe effects comparison

More Front Toe-out
  • Sharper initial turn-in
  • More responsive to steering input
  • Nervous/fast feeling on straights
  • Increased tire wear (scrubbing)
  • Hotter motor = higher FDR needed
More Rear Toe-in
  • More stable on throttle exit
  • Predictable under power
  • Less rotation/aggression
  • Significant drag = motor heat
  • Needs taller gear to compensate
๐Ÿ’ก Gearing impact

Toe creates rolling resistance. Every 0.5ยฐ of toe (front out or rear in) = ~1-2ยฐF motor temp at a normal track session.

That means you may need to adjust your FDR after changing toe to keep the motor in its sweet spot.

Quick check โ€” front or rear?

Car doesn't turn in fast enough. Which change helps?
๐Ÿ“ Measure Your Toe
Lesson 3 of 4

๐ŸŽฏ Precision Measurement โ€” Hub Is Truth

Tire sidewall measurements lie. Hub measurements are repeatable. Here's why.

Tires have molding lines, sidewall bulges, and wear patterns that make them unreliable for precision measurement. The hub face โ€” the flat machined surface where the wheel bolts on โ€” is the truth.

For CAMBER: measure angle at the hub face, not the tire. A 0.3ยฐ difference can be the difference between 'good' and 'great'.

For TOE: measure at hub height (center of wheel axis), not the tire top or bottom.

Precision checklist โ€” verify your technique

๐Ÿ’ก Digital caliper shortcut

For toe, you can use digital calipers: measure front-of-tire distance and rear-of-tire distance (at hub height). Difference in mm = toe in mm. Convert to degrees using tire diameter.

Lesson 4 of 4

๐Ÿ”— How Camber & Toe Interact

These aren't independent. Changing one affects the other's effectiveness.

Interaction 1: Toe-out induces dynamic camber in corners.

When you steer, the wheel arcs through its steering range. As it turns, the tire picks up additional camber (becomes more negative on the outside wheel). Toe-out amplifies this effect.

Interaction 2: Ride height changes BOTH camber and toe.

Lowering the car changes the arm geometry โ€” camber shifts, and if there's any bump-steer, toe shifts too. This is why you must RE-SET camber/toe after ride height changes.

Diagnosis โ€” what's really happening?

Select the symptom and see which fix addresses the ROOT CAUSE.

Symptom: Car pushes (understeers) in corners
๐ŸŽฏ Key takeaway

Always think CAUSALLY: which physical effect needs to change? Then pick the adjustment that creates that effect. Don't just blindly try all options โ€” diagnose first.

๐Ÿ Module 2 Complete!

You now understand camber, toe, precision measurement, and how they interact. Time to master springs and damping.

Start Module 3: Springs & Damping โ†’