The Thunderdome rules
USGT 21.5 Rules
v1Class RulesUSGTEffective Jul 28, 2026· Updated 3 months ago
Summary of recent changes
Current class specification.
Spec sheet
Governing
- Notes
- SXT 3.0 Medium (black cap) only; Snowbird Nationals 2020 rules; min 5 entries
Motor & ESC
- Motor type
- ROAR approved
- Spec motor
- Open ROAR racing spec motors
Tires
- Spec tire
- Gravity RC spec tire
- Tire additive
- Spec sauce only
1.Tires
Gravity RC spec tire.
2.Governing rules
SXT 3.0 Medium (black cap) traction compound only. Open ROAR racing spec motors. Snowbird Nationals 2020 rules apply unless superseded by class-specific governing bodies (USGT, U.S. VTA, Tamiya TT-02, etc.). Minimum 5 entries per class.
Version history
v1Published.
Jul 28, 2026