Grand Derby Race Specifications:

• Maximum Overall Width (including wheels and axles) shall not exceed 2-3/4";
• Minimum Width between the left and right wheels shall be 1-3/4" so car will clear the center guide strip;
• Minimum Clearance between the bottom of the car and track shall be 3/8" so the car will clear the center guide strip;
• Maximum Length (including wheels) shall not exceed 7-1/8";
• Wheelbase (distance between the front and rear axles, center to center) may not be changed from the kit body distance of 4-3/8".

​
Cub Scouts Regulations:​

• Weight of Car: Car may weigh no more than five (5) ounces (total weight) as determined on the official scales during race day check-in.
• Width of Car: Car can not be more than 2� inches wide.
• Length of Car: Car can not be more than seven (7) inches long.
• Height of Car: Car shall not be taller than three (3) inches in height.
• Wheels and Axles: The car shall roll on four (4) wheels. The wheels shall turn about the axle nails. The axle nails shall be firmly affixed to the wood of the car body. Wheel treatment (hub and tread smoothing and polishing) may not result in substantial removal of mass nor in reducing the tread (track contact) width from the original wheels. You can polish the axles. You may lightly sand the wheels to remove the molding seam on the tread. No other wheel changes are allowed. You may not use hubcaps, washers, inserts, sleeves, bearings, or bushings.

​
Shape ‘n Race Boys Brigade Regulations:​

• Weight of Car: Car may weigh no more than five (5) ounces (total weight) as determined on the official scales during race day check-in.
• Width of Car: Car cannot be more than 2� inches wide.
• Length of Car: Car cannot be more than seven (7) inches long.
• Height of Car: No height maximum.
• Wheels and Axles: No bearings, washers, bushings or springs are allowed. Wheels cannot be filled in with solid material or tapered to reduce running surface. Wheels can be sanded to remove seam and lubricated with powdered graphite.
• Loose Items. No loose items can be attached to the car.
• Entering the Race. Normally, boys can enter only one car. Some units allow boys to enter two divisions: one for cars built by a boy only and one for cars built by boys with adult help. Other units allow leaders and fathers to enter their own cars in a separate race. Boys should not enter cars used in previous years. Boys who are racing cars should be registered members of the Stockade unit.