1. Material: Cubmobiles shall be constructed of wood (except as noted below). Structural components (frame, axles, and seat back support) shall be made of 2” x 4” construction grade dimensional lumber, the lumber shall be structurally sound and free from splinters. The seat, seat back, and seat back support braces shall be made from plywood and the plywood shall be at least 3/8” thick.
2. Construction Techniques: Cubmobile components shall NOT be joined with nails (they will not hold and the Cubmobile will not be safe – therefore not allowed to race). Structural components shall be joined with metal; screws, lag screws, or lag bolts.
3. Size: Cubmobiles shall have a forty-eight (48) inch wheel base as measured from the center of the front wheels to the center of the back wheels. Cubmobile axles shall be 28 inches (not counting the wheel mounting hardware or wheels).
4. Wheels: Wheels shall be no smaller than 7 inches and no larger than 10 inches in diameter. Wheels shall be constructed of solid rubber (no inflatable tires). Wheels may have bearings if desired. Wheels shall be attached to the axle with a lag screw into the end of the axle. Lag screws must be at 3/8 inch in diameter and must be at least 3 ½ inches long. Wheel mounting hardware may not rotate during racing.
5. Steering: Cubmobile steering shall be accomplished through a pivoting front axle. The front axle shall have a steering rope (bridle) and steering limit blocks affixed to it. The steering rope shall be at least ¼ inch in diameter, shall be affixed to the axle via a through-hole and knot technique, and should be made of a synthetic material (nylon is preferred). The steering limit blocks shall be at least 3 ½ inches by 3 ½ inches square, shall be securely affixed to the front axle with screws, and shall be no further than 1/2 inch from the main frame. The steering axle bolt shall be at least 3/8 inch in diameter, shall be at least 4 ½ inches long, and shall have two nuts or a lock nut.
6. Brake: The (hand) brake shall be mounted with a 3/8 inch or larger bolt. The braking surface shall be made of rubber.
7. Seat: The seat shall be at least 15 inches by 20 inches and shall be affixed to the frame in at least two places. The seat back shall be at least 8 inches by 20 inches and attached to the seat back support in at least two places. The seat back support shall be braced on both sides of the frame.
8. Seat Belt: The seat belt and mount shall be judged by the inspectors to be able to restrain a scout in the event of a collision. The seat belt shall not be frayed or otherwise damaged.
9. Push Bar: Each car should have a stable "push bar".
10. Other: No weight(s) shall be added to the Cubmobile. No objects shall be mounted to the Cubmobile which may cause a safety concern for drivers, race staff, or race observers. All decorations (paint schemes, logos, etc.) shall be in good taste and in the spirit of the B.S.A.

CUBMOBILE CONSTRUCTION SUGGESTIONS AND HINTS

• Correct alignment will go a long way toward a successful race – that includes wheels that do not wobble (much).
• Use good materials – don’t buy the cheapest wood.
• Don’t ‘eyeball’ your cuts and drill holes – “measure twice – cut once”.
• Reinforce the rear axle (to stop it from moving at all) – even a little movement here could make steering very difficult.
• Scouts that practice driving their Cubmobile will do better.
• Ensure your Cubmobile meets the design standards – nothing could be worse than building a Cubmobile and not being able to race it