2014 Bull Run District Soapbox Derby
Saturday May 24th, 2014 (rain date 25th)
Victory Elementary School, 12001 Tygart Lake Dr,
Bristow, VA 20136
Times: 8:30 Setup (Volunteers Needed)
9:00 Registration and Impound
Cost: $5 per vehicle
to cover various costs
Bike helmet (Mandatory. No racer will be
allowed to participate without a helmet)
BSA Field Uniform (Class A) with long
Recommend long sleeves.
Unique car per Den/Rank. Can have multiple cars. All boys will
drive twice (Please keep it to about 5-8
boys per car)
- Note 1 – use two-sided
brake. Brakes with one handle on one
side of the center frame will cause fish-tailing.
- Note 2 – install steering blocks
almost flush to either side of front beam to limit steering.
- Note 3 –Bearing wheels are permitted
- Note 4 – Keep wheels between 5-8
inch diameter. Wheels taller than 8
inches can make the car more top-heavy.
- Note 5 – Boys steer with their
feet, not the rope. Do not block access
to the front axle when using a car body.
- 4 Timers (with stopwatches or smart
- Clerk of Course Assistants (order
behind the start)
- Lane Managers (keep the kids
reasonably on the track)
- Ramp Managers (put the cars on the
- Setup (brute labor)
Prizes: TBD. Awards for 1st, 2nd and
3rd fastest average time, as well as 3 Design awards.
Bull Run Cubmobile Specifications:
The Bull Run
Cubmobile is a modified version of the standard Cubmobile as seen in the Bear
Handbook. It has been reduced in size to control costs, improve portability and
make storage less burdensome on suburban scouters.
- Dimensions are no more than 22 inches wide by 46 inches long. The
vehicle must fit on the ramp.
- Wheels can contain bearings or not
- Wheels must be at least 5 inches in diameter and not more than 8
- Steering limiters are placed on the front axle to either side of the
frame not further than 1/8 inch from the frame of the car. (Safety – cars that
over steer flip their drivers.)
- The car must have a rope steering bridle. Not used for primary
steering but in conjunction with the feet.
- The driver’s feet must reach the front axle. The car is steered by the
- Wheels may use either lag bolts and washers mounted into the axles, or
a solid axle at the leader’s discretion. Cars with lag bolts will be inspected
for cracks in the axles for safety. A cracked axle will not pass inspection.
- Wheels may use any lubricant the leader chooses.
- Minor changes to the design are permitted provided they do not
compromise safety. The Red Toolbox kits previously used remain a valid design.
Parts List for Chassis only: (body is
1 @ 10 foot piece of 2x4
4 @ Wheels (8inch or smaller)
4 @ Lag Bolts (size dependent on wheels
1 @ ½ ” bolt with locking nut (4inch)
11 @ washers (size dependent on bolts
1 ½ ” wood screws (for the seat)
24 @ 2 ½ ” wood screws (for back axle and
1 @ 2’x2’ cut of ¾ inch plywood (for the
- The body is constructed of common 2x4 lumber.
- The front axle is connected by a single 3/8” wide bolt. Separate the
frame from the axle by inserting a washer between the two boards and use
washers on either end too.
- The rear axle is attached with four screws or bolts to the frame.
- The seat is attached with four screws to the frame.
- The seat back is attached to the frame by means of the 6in @ 2x4 piece
cut in half at a 15% angle
- The brake handle straddles over the center of the frame and the brake
itself straddles under the center of the frame, with connecting levers on
either side. A center brake is key to prevent fishtailing.
- Wheels may be attached using either a heavy bolt (lag) directly into
the axle itself. However, a solid axle is recommended.