Electrathon - Regulations, Design Rules, and General Competition Format

Formula Electrathon Experimental (F/Ex)

Electrathon competition - Mexico City (Zocalo)
Copyright notice
©1992 S.L. Van Ronk, 520 Pine St. Sandpoint, ID 83864
Used by permission of the author

Use of these rules are free to any school, individual, or group promoting Electrathon competition for non-commercial and non-advertising purposes. Use of this publication must include a statement of origin to acknowledge authorship. Please submit your name and address to author to receive written authorization for use and updates of material as they occur. Any commercial or promotional use of the text of this publication MUST be granted written permission by the Author.


The following rules and regulations are presented for those designing Formula Electrathon Experimental (F/Ex) competition vehicles. The rules are designed for the safety of the participants. This rule set was adopted from the Clean Air Revival 1992 Electric Motor Sport Regulations and Competition Guidelines. The CAR guidelines evolved from Australian Electrathon competition rules modified to more closely match US builders interests and parts availability as determined during a conference following the first American racing season in 1991. That conference defined two rule formats as Formula Electrathon (F/E) and Formula Electrathon Experimental (F/Ex) representing minor differences in approach between vehicle builders at that time. Both rule sets are now in common use and differ from each other only in small details. F/Ex rules allow wider variation in vehicle design and a simpler competition format. This permits more people to join the competition at considerably less expense, which has made F/Ex racing the fastest growing and most frequent electric competition format in the world. F/Ex racing has also become one of the most powerful interdisciplinary educational programs in the world continuously growing in high schools and universities world wide.

Many of the rules are aimed at space frame construction techniques. Vehicles that employ construction techniques other than those noted in the rules will be judged for their safety and handling in comparison with regulation space frame designs. In this way, it is hoped that new technologies will be incorporated into future vehicles.

F/Ex rules now form the basis of Electrathon competition programs in much of the US and Mexico with interest forming in several new countries. Each regional group has slight modifications of the standard rules to reflect interest and parts available in their own region. An example is Mexico using a 40 kilo battery weight limit. As new countries develop programs it will be necessary to hold another conference out of which a true and fair international standard will develop. We will present a comparison of the various rule sets in the near future.

These rules and regulations contain:

General Design Regulations

General Competition Format

Rules Of The Road

Appendix "A" - Electrathon Vehicle Groupings

General Design Regulations

A maximum of 64 pounds of batteries. Any batteries used for motor controllers, contactors, relays, solenoids, etc. will be included in the maximum battery weight. Batteries must be conventional production, rechargeable, lead-acid type. Batteries may not be modified to increase their performance. Batteries must be secured to the frame of the vehicle such that they will remain in place in the event of a vehicle roll over. Batteries must also be protected from damage in the event of an accident. If batteries are not the fully sealed type, they must be contained in a battery box which will retain battery acid in the event of a vehicle rollover.

Electrical System
All vehicles must have fusing or a circuit breaker between the motor and battery. A master disconnect switch (switches) or circuit breaker must be accessible by both the driver and by race officials during the race. The disconnect switch accessible to the race officials must be mounted within a red, equilateral triangle with four-inch sides.
Motor power must be "switched" such that the motor (motors) turn off automatically if the driver releases the throttle.
One square meter of solar cells is allowed on F/Ex vehicles. This area includes the area of the silicon and not the space between the cells). The cells must be safely affixed to the body of the vehicle, where they do not Protrude or endanger others.

Wheels and Axles
Vehicles must have a minimum of three load-bearing wheels in contact with the ground at all times. The wheels and axles must be strong enough to withstand the scrutineering tests for braking and maneuvering. Wheels must be covered if they could endanger the driver.

Minimum sizes have been established for steering parts in an attempt to avoid failures. Steering arms, rod ends (ball joints) and the hardware used to mount all steering components must be no weaker than 1/4-inch diameter steel rod. King pins must be made of a material that is as strong or stronger than a inch solid steel rod.
Vehicles must have a minimum turning radius of no more than 25 feet.

All vehicles must have mechanical or hydraulic brakes on at least two wheels. Brakes must be able to stop the vehicle from a speed of 25 MPH within 40 feet. Vehicles must have brakes on at least the pair of wheels that are "on the same axle" (either both front or both rear wheels). Effective braking will be checked before the race.

Drive Train
All chains, gears, etc., must be covered if they could endanger the driver, the driver of another vehicle, or spectators.

Helmets and Clothing
All drivers must wear DOT-approval (full-face helmets are recommended). Helmets must be worn with the chin straps correctly fastened. A label with the driver's name, blood type, allergies, and date of last tetanus shot must be affixed to the back of the driver's helmet. Drivers must wear heavy clothing; long sleeved shirts, long pants, enclosed shoes and gloves (made of leather or other protective material).

Mirrors and Vision
All vehicles must have at least one rearview mirror, with a total mirror area of no less than eight square inches. The driver must have at least 270 degrees of unobstructed vision of the track, not including vision of the track seen through mirrors. Vision obstructed by frame members is an exception to this rule. Eye protection must be worn by drivers of open vehicles. It is recommended for drivers of enclosed vehicles.

General Construction
Vehicles must be free of all sharp protrusions, including on the vehicle surfaces and the frame members. The maximum length of an Electrathon vehicle is 13 feet. The maximum width is 5 feet.

Vehicle Numbers
Vehicles will be issued numbers by the organizers of the series in which you are participating. An area of 12 inches high by 30 inches long, is recommended to be reserved on the front, and on both sides of the vehicle, for the sponsor/vehicle number decals.

Each vehicle will be inspected by scrutineers before it is allowed to race. All vehicles must be available for technical inspection at least one hour before race start time. The driver of each vehicle will remain with the vehicle. Vehicles which do not conform to regulations will not be allowed to race, except at the discretion of the scrutineers.

Crash Protection
All vehicles must have frame members and padding that protect the driver in the event of frontal, side, and rear collisions. The minimum size of such frame members will be:
3/4-inch O.D., round or 3/4-inch square tubing with;
0.065-inch wall thickness for mild steel
0.058-inch wall thickness for 4130 chrome moly and
0.083-inch wall thickness for aluminum.
Frames that are not constructed of any of the above materials will be allowed at the discretion of the scrutineers. Padding must be provided to prevent the driver from being injured from contacting the roll bar in an accident. Padding must be at least 3/4-inch thick and made of closed cell foam. (Closed cell foam pipe insulation is sufficient.)

Roll Bars
The roll bar must extend at least 2 inches above the driver's helmet. It must be cross braced to the chassis, either forward or rearward from a point that is no more than 6 inches from the top of the roll bar. The bar itself must be made of tubing similar to that used for crash protection. An inspection hole, at least 3/16-inch in diameter, must be drilled in a non-critical area of the roll bar hoop to facilitate verification of its wall thickness.
Padding must be provided to prevent the driver from being injured from contacting the roll bar in an accident. Padding should be 3/4" thick and made of closed cell foam. (Closed cell foam pipe insulation is sufficient)
Roll bars that are constructed of materials other than those approved above, will be allowed at the discretion of scrutineers. Racers must demonstrate the physical strength of such roll protection to scrutineers. .

Head Restraint
A head restraint, capable of withstanding a force of 100 pounds in the aft direction is required to prevent whiplash. Padding must be provided to prevent the driver from being injured from contacting the head restraint hardware in an accident.

Seat Belts & Arm restraint
All vehicles must have at least a lap seat belt. Seat belt strapping is to be at least 2 inches in width (automotive) and must be strong enough and fastened to the vehicle is such a way that the complete vehicle, with batteries, can be lifted from the ground by the seat belt alone. The seat belt must contain the driver so that he/she does not contact the ground in the event of a roll over. A wrist or arm restraint must be used in any vehicle where the driver can extend his/her arm outside the body of the vehicle. This is to prevent injury from the automatic response of using the arms as protection in case of roll over. This has been the only cause of serious injury so far experienced in Electrathon competition. Drivers must be able to exit the vehicle unaided in 20 seconds or less.

Driving Position

Driving positions where the driver's head is more forward than his/her knees are not allowed in Electrathon vehicles.

General Competition Format

The following format rules vary slightly depending on competition organizer. Most competitions are simple to enter by just showing up with a qualifying vehicle. Major regional championships have more complicated procedures.


To enter events, complete entry forms provided by the event organizer. Multiple entries require seperate entry forms and fees for each car. In some cases multiple drivers are allowed to share a car, but each driver is required to submit a seperate entry. Many organizers require competitors to be a member of the organization promoting the competition.


Many competitions charge an entry fee of up to $25. Some will waive the entry fee if the competing team provides track workers. Some competitions require special fees to cover membership in their organization or insurance.


Entry deadlines are usually printed on registration forms or publicity flyers.


Refunds of entry fees are often given to competitors who do not qualify to start or fail to arrive at the track, although some organizers keep entry fees as administrative costs. Requests for refunds must be submitted in writing to the office of the competition organizers along with any unused vouchers. Refunds are usually subject to a charge for the value of spectator entry or Pit Passes if such fees apply.


Pits are strictly controlled during race times. Pit passes must be worn in plain view at all times in the paddock area and the racing pit. Persons working on a vehicle in the pit lane must wear at least a T-shirt, long pants and closed top shoes.

Organizers reserve the right to refuse entry at any time with only such notice as circumstances permit.

A participant must prove competent ability to operate a vehicle and conform the race stewards directions. Methods of determination vary from organizers. Usually a drivers licence is required.

A valid, current driver's license, recognized in the State where the competition is held is generally required. Many school events do not have this requirement, but do have an alternative system. It is recommended that participants obtain as much training and instruction in performance driving as is possible.

A medical exam is recommended every two years. The judgement of the event medical personnel will be final in cases of a driver's medical ability to participate.

A driver must usually show his or her license and a pit pass voucher in order to register. Pit crews/guests must present signed vouchers to register and receive pit passes.

All vehicles must be presented for tech inspection before each event. Each vehicle will be given a thorough inspection at or before competing in the first event entered, at which time a serial number will be stamped on the vehicle chassis and a log book issued. Log books must be kept with the vehicle for which they are issued and presented at registration for each subsequent event. Properly prepared vehicles will be issued a tech approval sticker which must be displayed for that particular event. Any car involved in an on-track incident must stop at impound (tech) upon leaving the track. All event entries, track incidents, and violations or warnings will be recorded in the vehicle log book. Some organizers do not require log books which requires technical inspection at each race.

Vehicles entering the course at any time with mounted cameras or similar equipment must have an annual approval from Tech (Scrutineer) indicated by a Special Equipment Sticker visible from the exterior of the vehicle.

Permanent vehicle numbers are issued by competition series organizers. Numbers must be visible to lap counters. For permanent electric vehicle number assignments call your nearest competition organizers.

Race results will be made available at Race Central as soon as is reasonable after race completion.

Tools, parts, lubricants, electric power and compressed air are the responsibility of the entrant, unless otherwise noted in the acceptance letter. Participants may not plug into track facility power without the express permission of the track management.

Electric vehicle competition event organizers are not responsible for the loss or theft of any item brought on the premises.

17) PETS:
Pet not on a leash or caged will not be permitted at any time. Leashed pets should be restrained by an adult at all times.

Protests will be accepted only at the discretion of the Series Chief Steward. The protest fee is $25, which will be refunded if the cause of the protest is determined by the Series Chief Steward to have merit. Most matters can be resolved by the Series Chief Steward without the necessity of a protest.

No participant (driver, crew or worker) may consume intoxicants in the paddock area or elsewhere on the course until after the last checkered flag of the day.


Electric vehicle competition is not the same as competitions for conventional sports and racing cars. Although competitive, the primary purpose is NOT only winning, but driving and innovative engineering under competitive track conditions in a safe and enjoyable environment for all participants.

Electric Vehicle Competition events include vehicles and drivers of many performance levels and abilities. This requires the exercise of great care, prudence and courtesy in traffic and in passing. The slowest vehicle and driver have as much right to be on the course as the fastest, and all drivers must conduct themselves accordingly.

On the rare occasion a safety vehicle is put on course, each turn station will display a stationary yellow flag and the start will display a yellow flag and a "PACE CAR" sign. Prior to leaving the circuit, the safety vehicle will extinguish its flashing lights. The green flag may then be shown to the leader. At the green flag, all yellow flags will be simultaneously lowered and competition resumes throughout the course. All vehicles must hold position until the green flag is displayed.

The following flag signals shall be obeyed without question:


Green -- (ordinarily displayed at Start/Finish (S/F) only) Competition is under way (started) the instant the green flag falls, and passing may begin.

Red -- When a red flag is displayed at S/F, all other flag stations will display a waving black flag. All other flags will remain applicable to the respective corners and individual incidents. Reduce speed and continue in a safe manner to just past the start/finish and stop at the side of the track. Lap charts and restart order will revert to the last fully scored lap prior to the red flag.

Yellow -- The CAR interpretation and application of the yellow flag is as follows:

Motionless/Standing: Take care, danger, slow down, signal recognition, maintain interval to the car ahead, NO PASSING FROM THE FLAG until past emergency area.

Waving: Great danger, slow down, signal recognition, maintain interval to the car ahead. Be prepared to stop-NO PASSING FROM THE FLAG until past emergency area.

(For definition, slow down means: Reduce speed sufficiently to safely make any avoidance maneuver necessitated by the situation. Signal Recognition means: Acknowledge to the corner workers, by a nod of the head or a hand signal, that you have seen the flag.

Black -- At S/F, or Black Flag Station: Complete the lap you are on. Then stop racing and proceed to S/F or the designated "Black Flag Area" for consultation.

At S/F, furled -- Warning: You are driving in an unsafe or improper manner. If continued, you will be given a full black flag. On corner -- the race has been stopped, there is a red flag displayed at S/F. Stop racing, and proceed to S/F exercising extreme caution and be prepared to stop.

Black with Orange Ball in Center: (At S/F or black flag station only) -- There is something mechanically wrong with your vehicle. Proceed to your pit at reduced speed.

Checkered -- You have finished the event (or practice session, etc.) Complete one more lap cautiously, and retire to the paddock, or report to impound area as required.

To be considered a starter, a vehicle must receive the green flag at the start. Cars entering the competition after the initial start are also considered starters.

The vehicle in front of another has the right- of-way, and need not yield to the vehicle behind. However, if the vehicle ahead is clearly much slower than an overtaking vehicle, as a matter of sportsmanship, the slower should yield the right- of-way to the much faster vehicle when it can be done safely.

The responsibility for the decision to pass another vehicle, and thus for the safety of the pass, lies with the overtaking driver. The overtaking vehicle must leave room for the overtaken vehicle, and the pass must be completed without requiring the overtaken driver to take evasive action to avoid contact with the overtaking vehicle.


It is the responsibility of the overtaken driver to maintain a consistent and predictable line or course of travel, so that an overtaking driver will not find himself committed to a passing line only to have the overtaken vehicle suddenly swerve into that line, resulting in unavoidable body contact.

It Is absolutely contrary to the spirit of Electric Vehicle Competition. The driver judged at fault in an involuntary contact situation WILL be penalized, up to and including removal from participation. A driver adjudged at fault for a deliberate contact, or for repeated contacts, or for an involuntary contact involving great carelessness or negligence, SHALL BE excluded from participation in that event, and may be suspended from further participation for such period as adjudged appropriate.

A vehicle which has left the course with all wheels, or which has sustained damage during an event, MUST proceed directly to the pits to be inspected for damage by a designated official before being allowed to return to the track.

It is forbidden to drive or tow a vehicle during the course of an event on the circuit or in the pits in a direction opposite to that in which the event is being run. A vehicle which overshoots its pit must be pushed back by hand, or continue for another lap.

If a driver is forced to stop his vehicle on the circuit during an event, It is his first duty to, insofar as possible, place it in such a manner as to cause no danger or obstruction.

Any driver who is operating a vehicle in a manner deemed to be dangerous will be black flagged and required to stop and the Black Flag Station in the working pits to be (A) warned, (B) removed from the circuit, or (C) suspended or banned from future CAR events.

All accidents will be thoroughly investigated. If caused by carelessness, overly aggressive or dangerous driving, appropriate action will be taken.

Novice driven cars must display a contrasting 6-inch-high letter "N" on the cars number on each side of the vehicle and a 5-inch-square, day-glo panel at the rear of the car. Novice classification will be at the discretion of the Series Chief Steward and will be so indicated in acceptance letter. This would include all drivers admitted into competition with a waiver on the drivers licence rule, or any driver entering an event with marginal vehicle operational skills, or receiving black flag warnings as deemed by the Series Chief Steward. The Series Chief Steward will have the right to require a demonstration lap prior to any event in order to determine driver skill.

At this time there are several primary groups being developed: All were Derived from Australian Electrathon rules and modified to meet the interests of the particular group organizing competitions.

Formula E (F/E) - Formula Electrathon vehicles are required to be fully enclosed with lightweight streamlined bodies and are built for maximim speed and distance on oval tracks. These vehicles usually use low rolling resistance bicycle type tires and very low frontal area. They tend to be the fastest Electrathon vehicles, and the most expensive to construct.

Formula Ex (F/Ex) - Formula Electrathon Experimental allows variations in the specific equipment and configuration requirements of Formula E. The class was originally defined in 1992 to reflect the changing interests of US competitors, many of whom wanted to build vehicles based more on overall handling characteristics, and and driver skill. F/Ex competitions are usually raced on "autocross" type tracks with lots of corners. They do not require enclosed bodies and a wider range of design possibilities is permitted. It is also the least expensive of all Electrahon vehicles and the easiest to organize informal competitions. Because of the simple format and wider range of design possibilities, F/Ex has become the most popular Electrathon class in high schools and among international competitors.

High School Classes - Derived from either class, with such added precautions as needed for High School events. F/Ex based high school Electrathon is rapidly expanding throughout the US, Mexico, Europe and Asia. F/E based high school classes exist in the Midwestern US, the Pacific Northwest, and Maine. F/E based high school groups are almost all associated with Electrathon America and subject to a complicated set of restrictions issued from the southern California board of directors. F/Ex based high school classes are all either independently organized or under the jurisdiction of a local educational body.

Two Wheel Classes - There have been occasional two wheel vehicles with the same battery restrictions allowed in Electrathon competitions. This has always stirred a debate about creating a seperate class for two wheel Electrathon competitiors. We support this effort, but at this time no class has been yet defined.

Leaners - Articulated frame three wheel vehicles or three wheel vehicles with independently articulated swing arms allowing the vehicle to lean into corners like a motorcycle have been frequently entered in Electrathon competitions. These vehicles may compete in either F/E or F/Ex competitions if they conform to all other rules. This is rare in F/E, but fairly common in F/Ex. Under the original F/Ex rules such vehicles were subject to a different set of driver safety standards requiring motocross type body protection and no seat belt. Talk about creating a seperate class for leaners has not materialized due to the rarity of these type vehicles.

Super Electrathon - Many Electrathon competitors quickly wish to enter faster competitions with vehicles designed for greater battery weights. This has led to widespread discussion and some prototypes for Electrathon type vehicles that carry up to 125 and sometimes 250 pounds of battery. These vehicles use motors in the 4 to 6 hp range and stronger frames, but are built on the same basic principals as the standard F/E and E/Ex. So far a standardized set of rules has not been adopted and such vehicles usually run exhibition heats only.

The Series Chief Steward may make exceptions to the group limits in order to achieve a group balance. A driver's ability and lap times may also be considered in establishing racing group assignments.


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