The Thunderdome rules
Touring Stock 21.5 Rules
v1Class RulesTouring Stock 21.5Effective 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
- Spec brushless
- Motor turn
- 21.5T
Tires
- Tire additive
- Spec sauce only
1.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 Snowbird Nationals 2020 rules apply unless superseded by class-specific governing bodies (USGT, U.S. VTA, Tamiya TT-02, etc.).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