Here is some more info (for those who may not wanna "look it up themselves"
Competition Classes
CLASS OVERVIEW
The purpose of the Challenge USA Electrathon classes is to allow cars/drivers to compete
with their peers. Cars are assigned to classes based on their cost and different design criteria. To
encourage new construction and designs, no vehicle may compete in Classes 1, 2, 3, or 4 for
more than three years. After the third year that a vehicle competes, its chassis must be retired,
although other components of the vehicle may be used in future vehicles. During the second and
third year that a car competes, two of the major systems (frame, electronics, steering, brakes,
body, suspension, motor/drivetrain, and wheels) must be modified from the previous year’s
competition. These changes will be documented in monthly and final reports.
The intention of the vehicle class system is to foster creativity among teams and
encourage students to continually look at how to make improvements to their vehicles. As such,
the system is designed for vehicles to only be allowed to “move up” a class. If a vehicle in an
“Entry” class finishes in the top half of the class in total season points, that vehicle is required to
move up to the corresponding “Advanced” class the following year. Cars in an “Advanced” class
that finish in the bottom half of season points for the class may not move down a class, but will
remain in their current class.
CLASS 3 – ENTRY LITHIUM
Overview
• This vehicle must be a first-year car, or the car must not have placed in the top half of the
season ranking for all Class 3 vehicles from the previous year’s competitions
Design Components
• Vehicles must follow the “Vehicle Design Rules” as outlined in the next section AND...
o Chassis must have an enclosed body except for driver entry and egress. All vehicle
components and the driver’s body must be enclosed within the body.
Cost
• The vehicle must cost less than $3500. Teams may have extra parts, such as additional
sets of batteries, tools used in the pits, spare vehicle parts, and driver safety equipment.
The cost of the vehicle is determined by the cost of all materials and components on the
car at the time it is presented for competition.
Braking
• No regenerative braking systems allowed (aside from those pre-built into hub motors)
• Vehicles must have braking mechanisms on at least three wheels
Batteries
• Batteries may be any type of sealed production batteries that are under 1200 watt hours
• No solar panel recharging permitted during the challenge, however using solar panels to
recharge batteries before the endurance competition is permitted
Vehicle Design Rules
The following vehicle design rules are generic to all ChallengeUSA Electrathon vehicles. If the
rulebook does not explicitly state that something is allowed, it is not allowed without approval
from ChallengeUSA officials.
GENERAL
1. There is a $3500 limit on the value of the material used in the construction of Class 1 and
Class 3 cars, excluding brakes or professional welding for critical safety items
a. This $3500 limitation is for the parts and materials used in the construction of the
car as it is presented for the competition
b. This $3500 limitation specifically excludes driver clothing and safety equipment,
pit tools, spare parts, and spare batteries
c. This $3500 limitation does include the batteries in the car during the competition
d. Student labor is not charged and factored into this limit, but other “volunteer
labor” must be included in the vehicle cost at a reasonable rate
e. All teams are required to submit documentation (needs a link) with any car
entering a competition. This documentation must include a listing of ALL
material used in the vehicle, regardless of whether it was purchased or donated.
Documentation is to include the actual/estimated value and the source of the
material. Documentation must also include an estimated value of volunteer labor.
These forms must accompany the vehicle in order to enter a competition, even if a
team does not complete the final report.
2. The maximum length of a ChallengeUSA Electrathon vehicle is 12 feet. The maximum
width is 4 feet (measured at the widest point of the entire vehicle with body material
attached.
3. The minimum track width (measured from the center of one wheel to the center of the
opposite wheel) is 24”.
4. The maximum weight of a ChallengeUSA Electrathon vehicle is 350 pounds.
5. Cars with a wheelbase of less than 6’ must have a lower center of gravity to prevent
rollovers
6. No vehicles may be designed in a way that would position the driver’s head in front of
his or her torso, or legs. The driver must be positioned feet-first in the vehicle.
CHASSIS/FRAME/CRASH PROTECTION
1. All vehicles must have frame members that protect that driver in the event of a collision
from any direction The minimum size of all frame members that protect the driver (any
frame member from the seat forward) and protect the batteries will be 1” OD round or 1”
square tubing with the following wall thicknesses:
• .0625” (16 gauge) for mild steel
2. Behind the firewall (except around batteries) .750” OD round or .750” square tubing will
be allowed
3. Frames for Class 4 vehicles may be constructed of other materials, provided that it is
demonstrated and documented that alternative materials provide equal or greater
structural strength and protection
4. The vehicle must have a fixed floor pan the prevents any part of the driver from
contacting the ground
5. Minimum ground clearance for any vehicle will be 2”. •
Vehicles with tires that have a sidewall height of over 2” must have a ground clearance
that exceeds the height of the tire sidewall to keep the vehicle off the ground in the event
of a flat tire
6. Maximum ground clearance will be no more than 8”
7. Each vehicle shall have structural members that meet frame member requirements at the
front of the vehicle that act as a bumper to protect the feet of the driver and to prevent
intrusion into another vehicle in the event of a crash. The minimum dimensions of these
structural members shall be eight inches vertically and eight inches horizontally (that will
not fit through the 6” space defined in item 8 below). Any material in front of this 8”
bumper must be collapsible so as to not intrude into another vehicle in the event of a
crash, Teams must be able to demonstrate that the material is collapsible with minimal
force during the inspection process (can be done using a video taken at school, does not
need to be destructive)
8. Frame members on the side of vehicles must be designed to help prevent another vehicle
from intruding into the driver’s compartment in the event of a crash. No spacing larger
than 6 inches is allowed on the frame of the vehicle around the front and sides of the
driver’s compartment and the battery box(es), as tested with a 6” diameter disc. The 6”
disc must be prevented from intruding into the driver compartment by 1” OD (square or
round) tubing
9. Side impact protection must extend up to the top of the driver’s shoulder
ROLL CAGE
1. Vehicles must be equipped with a roll cage and driver compartment that will withstand
impact and protect the driver. The Driver Compartment is defined as the portion of the
car that the driver is completely contained within. The roll cage must extend high enough
to provide clearance above the helmet of the tallest driver.
2. The driver’s helmet must be positioned directly below the roll cage and centered front to
rear and side to side.
3. The roll cage will consist of two continuous loops that begin and finish at the base of the
chassis and may be either longitudinal or transverse in configuration, with cross bracing
between the loops to connect the two, centered over/above the driver’s helmet.
a. The roll bar must be braced to the chassis, forward and rearward. The rearward
brace will be no more than six inches vertically from the top of the roll bar. The
forward bracing shall form a protective cage around the driver and be designed to
protect the driver from front and side impact
b. Frontal driver protection is determined by drawing a straight line horizontally
across the roll cage frame members in front of the driver’s face. The straight line
should be a minimum of two inches from the driver’s face when wearing a helmet
4. The roll cage must be made of tubing that meets the minimum standards for frame
components (see item #1 in Chassis/Frame/Crash Protection above).
5. An inspection hole, at least .125” in diameter must be drilled into a non-critical area of
the roll bar to permit inspector confirmation of wall thickness
6. All parts of the driver must be completely inside the frame cage at all times when in the
normal driving position, with hands on the steering mechanism in any position
INTERIOR
1. Padding is recommended, but not required be installed on all frame/roll cage members
from the driver’s waist up.
a. Padding (if it exists) is suggested to be at least .5” thick and made of closed-cell
foam (most pipe insulation has a .5” wall thickness)
b. Padding (if it exists) is suggested to be installed using a method other than cable
ties
2. A head restraint, capable of withstanding a force of at least 100 pounds in the rearward
direction, is required to prevent whiplash.
a. The head restraint is recommended, but not required to be padded with at least .5”
thick closed-cell foam
3. All Class 3 and Class 4 vehicles must be equipped with a full firewall behind the driver,
extending from the floorpan of the vehicle to the rollbar, and from one side of the seat to
the other. The only openings in the firewall should be for the safety harness, and should
be as small as possible
a. The firewall will help protect the driver in the event of a chain breakage, and will
prevent clothing from being caught in the drivetrain
