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Derby car Racing is the constant search for the peak performance based on physics principles.


The DERBY CAR competition for 6th graders is not only of play and excitement, but also great way of learning some basics in science. This event and its Learning materials explain the hidden science in very simple and practical way.

The competitors are expected to build a FREE WHEELING CAR out of any materials of their choice, and run it to win the race.





Build a four wheeled freewheel car that can run a distance of 5 meters (including the slope) in fastest possible time.

Time starts at count of ‘zero’ call and ends at moment when ‘finish’ flag is knocked down.







  1. The car should be an unpowered freewheeling car.
  2. Such modified or rebuilt cars must also meet the dimension and other rules as for the first round.
  3. Competitors may buy a Derby car kit from our website if they wish. They may use it for purposes of trials, experiments, practice or for competing. However buying kits from our website is optional and is made available for competitor’s convenience only. Buying from cognium will not earn any extra credits at the competition.
  4. Competitor shall ensure that parts bought from sources other than cognium, conforms the rules of the competition, failing which the model will be disqualified.
  5. There will be a revised problem statement for the final round. These revisions will be announced after completion of first round. Winners of the first round will, if they feel necessary, modify or rebuild their cars to meet the revised problem statement.



Those models which have passed the inspection will be placed on the start line of the track. The cars are placed to rest against ‘start pin’ which prevents the cars from rolling down. At the zero call of countdown, the start pin is released and cars start rolling down. Also at the release of start pins, electronic timers start counting the time elapsed. Each track /car has an independent timer. The timers stops when the car knocks down the finish flag. The time clocked by each car is displayed on the timer. Knocking down the ‘Finish’ flag is essential for completion of the race. A car is not considered to have completed the race if the car touches finish flag, but does not knock down the flag






  1. Dimension Rules
  2. Overall length of the car shall not exceed 150 mm.
  3. Overall width of the car shall not exceed 65 mm.
  4. Overall height of the car shall not exceed 65 mm.
  5. The car must fit in box 65mm x 65mm x 150mm.
Clearance under the car min 8 mm
  • The car must have 8mm minimum clearance underneath the body so it does not rub on the track.




  1. Minimum outside diameter of wheel (including tyres)- 25mm.
  2. Maximum outside diameter of wheel (including tyres) – 40mm.
  3. The axles should have diameter of 4 mm or less. (tolerance of 0.1 mm over 4mm is allowed)


  1. Total weight of car should be 100 grams or less.


  1. The chassis of the car (part that holds the axles) must be made of wood. Any type/shape of wood may be used, it can be shaped or cut in any desired way.
  2. The car should not use ball or roller bearings.(rolling contact bearings not permitted)
  3. Bush bearings of any material can be used.

example of bush bearings.

  1. Only graphite powder lubricant is permitted.


The derby car runs on potential energy only, as it is placed high on a sloping track.  It gathers sufficient speed while rolling down the slope and continues to run on level section of the track. The car is a freewheeling car. I.e. The car rolls on free wheels only and no drive mechanism is to be used.

General Rules

  1. First inspection of car will be ‘self inspection’ by the competitor. He shall complete and submit the self inspection form on or before the specified date.
  2. A readymade or bought out car will be disqualified.
  3. A car will be disqualified if found not conforming the dimensions or has prohibited parts, or does not conform to information submitted in self inspection form.
  4. Each car will be re-inspected at the competition venue and must pass inspection before it will be allowed to compete.
  5. Once a car submitted at the arena and passes inspection, it is considered as entered into the race, no modifications are allowed after inspection and acceptance at inspection desk.
  6. If any competitor wishes to modify his car, the car shall have to undergo inspection again and confirm that modifications do not violate any rules.
  7. The inspection committee has the responsibility and authority to disqualify those cars that do not meet any the rules.
  8. A competitor whose car is disqualified may modify his car to conform the rules and represent it for competition. Such representation will be accepted only if made before call for last run of the event is announced.
  9. Lubricating oil of any kind is not allowed. Only graphite powder lubricant must be used.
  10. If a car suffers a mechanical problem after inspection but before the run (i.e. Loses an axle, breaks a wheel, etc…), the participant will have up to five minutes to fix the car.
  11. The run may be held 5 minutes later than announced time in above case. If it takes longer time to fix the car, a new run will be allotted for such a car. Rest cars will run at the appointed time. Such car will be accepted subject to passing the re inspection.
  12. A car will be disqualified if a car leaves the track during the run and obstructs any other car.
  13. A competitor will be disqualified if he touches any car during the run (from the event of flag off to the event of timer reset)
  14. A car which suffers a loss of time due to obstruction from other car leaving its track, such timing will be written off and the suffering car will be allotted a new run.
  15. If a car leaves its lane, the competition in charge, at his discretion, may inspect the track and, if a track fault is found which may have caused the initial violation, he may order the race to be rerun after the track is repaired.
  16. In the event of any interference of any kind during the countdown or during the run, the judges may decide a rerun.
  17. The track’s electronic timers will record finishing place for all cars in each race. In the event of Technical difficulties, instrument failure, power failure or such other difficulties, the Finish Line Judges will determine the order of finish and will be binding on all competitors. They may use video/photo recorded at the finish line
  18. All decisions of the judges are  final and binding to all competitors
  19. All timings are by the official timers/clocks. All other timers clocks will not be considered for the purpose of determining the rankings
  20. Only Track Officials will be permitted in the track area.
  21. Weight by the official scale that is used at car check-in shall be considered final.




Prohibited Items  (which cannot be used)


  1. Readymade cars or sub assemblies from ready made cars.
  2. Magnets, springs or suspension systems of any type.
  3. Starting devices, finish line devices, propellants, or propulsion systems
  4. Wet paint, or Sticky substances
  5. Glass or excessively fragile parts
  6. Electronic or lighting devices
  7. Axles and wheels attached to any device that mechanically alters rotation or spin.
  8. Loose objects on car. All weight must be securely fastened or embedded in the car.
  9. Any part of the car coming off during the run will be considered as ‘car going off track’ and will attract penalty points as specified in rules.




Length of slope- 200 cms.

Height of slope- 70 cms.

Total length of track- 500 cms.





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