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Dial Your Own Handicap
JDB Class Description
Junior Drag Bike was created for competitors between the ages of twelve and eighteen inclusive. Racing Production Street Motorcycles of any age, modified to the limits described in the class regulations.
Purpose-built drag racing motorcycles with fully fabricated frames based on Production Street Motorcycles may be granted homologation approval only upon sub-committee approval of application.
A three-person sub-committee, consisting of two whom have recognized skills and experience relevant to the category, has been appointed to address safety training, and homologation approvals within existing IHRA Australia policy on the class.
NOTE: Two- stroke and off-road motorcycles are not permitted, Capacity limits apply to the actual displacement of the engine. The dial your own handicap system is used. Junior Drag Bikes are limited to competition over 1/8 mile.
Two categories and performance levels are provided.
Class Designation: JDB
Eliminator: Junior Drag Bike
For riders between the ages of 13 and 18 years inclusive. limited to ET no quicker than 8.90 seconds and Top Speed not faster then 80 mph (129 km/h).
Class engine capacity limits 161cc to 350cc
For riders between the ages of 12 and 17 years inclusive, limited to ET no quicker than 9.90 seconds and Top Speed not faster than 70 mph (113 km/h)
Class engine capacity limits 120cc to 160cc
NOTE: A one-time only allowance of one tenth of a second during qualifying rounds only for breaching class limits. Any vehicles running faster than the one tenth of a second allowance or running a time within the one tenth of a second allowance more than once, will be immediately disqualified and take no further part in that event.
A one-time allowance for excessive wheel standing during qualifying rounds. Any motorcycle running outside this allowance more than once, will be immediately disqualified and take no further part in that event. Excessive wheel standing is defined as a deliberate and sustained wheel stand. To be determined by Chief IHRA Australia Steward or his designated observer.
Persistent breaches of exceeding class limits may result in tribunal action. Class: One tenth of a second allowance (during qualifying rounds only)
Qualifying Class Limits
Elimination Class Limits
NOTE: Please be advised that it is the responsibility of Parents/Guardians of Junior Drag Bike competitors to withdraw your racer/racers completely from any event where they run quicker than the allowable ET cutoff, as detailed above. If this is not done, a penalty of two meeting suspensions will be imposed and any points gained at that event will be forfeited. Repeat offenders will face up to 12 months suspension and up to a $1000 fine. After the event is completed, all run sheets will be checked, and any team found to have breached this rule will be notified.
The Top Qualifier for the JDB Eliminator will be decided by the quickest Elapsed Time relative to class minimum. IE: A/JDB = 8.90
B/JDB = 9.90.
  • Paired Runs: Paired runs between Junior Drag Bike vehicles and those from any other category is prohibited.
  • Performance Testing: A/JDB Competitors must complete six runs between 8.90 and 9.40 seconds to the satisfaction of the officials at IHRA Australia sanctioned events to be eligible for competition in A/JDB. B/JDB Competitors must complete six runs representative to the class to the satisfaction of the officials at IHRA Australia sanctioned events to be eligible for competition in B/JDB. These Runs must be individually noted on the appropriate licencing forms and may be run a combination of events at multiple tracks.
Class Regulations
  • Engine: OEM Engine for Model used required.
  • Water Coolant: Non-glycol based and suitable for motorsport. Glycol based coolant additives are prohibited.
  • Engine: Any internal modifications permitted provided original cylinder(s) and crankcase castings are retained.
  • Ignition: OEM Ignition only.
  • Silencer or muffler optional
  • Exhaust: Aftermarket exhaust system exiting to rear of rider's footpegs permitted.
  • Fuel: All classes restricted to petrol only.
  • Taps must be installed in fuel lines except on EFI factory engines that are fitted with operating factory tip over sensor.
  • Induction: Factory (or OEM) Induction required for model used. Onus of proof on entrant.
  • ECU: OEM ECU required where Factory Fuel Injection is retained but may be supplemented with aftermarket non-reactive controllers, specifically accepted by IHRA Australia, that enhance existing functions. Onus of proof on entrant.
Liquid Overflow
  • Must be installed, if the vehicle is capable of discharging liquid onto ground.
  • Appearance: All bodywork must match frame model used. All machines must bear resemblance to original production machine. Models that have a fairing and screen fitted standard must use them or replicas. Factory production fuel tank for model used is required.
  • Screens: Must be thin and flexible for safety reasons.
  • Mirrors: Mirrors and other obstacles in the proximity of the rider must be removed.
  • Lighting: Original taillight must be used and operative.
  • Headlight: Original headlight or facsimile required.
  • Appearance: Replacement replica bodywork permitted.
  • Indicators: Removal of Indicators permitted.
  • Instruments: Removal or replacement of existing instruments with aftermarket units permitted.
  • Ballast: Ballast is prohibited.
  • Handlebars: All tubular handlebars must be plugged on ends.
  • Throttle: All bikes must have a self-returning twist grip throttle.
  • Kill Switch: A positive action ignition kill switch (not button) must be mounted within reach of the handgrip.
  • Lanyard: A “lanyard” type kill switch must be fitted and be attached to the rider while operating.
  • Steering: Steering dampers are required.
  • Handlebars: Clip-on bars permitted. Handle bar grips must be no more than 150mm (6 inches) in front or behind the fork stem with a minimum of 380mm (15 inches) width and no more than 300mm (12 inches) above the seat.
  • Throttle Stops: The use of throttle stop devices is not permitted.
  • Delay Devices: The use of delay devices is not permitted.
  • Two-step rev limiters: Clutch-activated rev limiters are not permitted.
  • Frame: Original OEM frame required.
  • Frame: No frame modifications permitted.
Upholstery Required
  • Seat: Original seat base to be retained.
  • Seat: Trimming of upholstery to a minimum of 25mm (1 inch) at the front half of the seat permitted.

§  Chain Guard: Chain guard required. Stock chain guard may be retained.

§  Extended Chain Guard: Exposed chains must be covered on their top run between the centre lines of the sprockets. Minimum material specifications for chain guards: 25mm (1 inch) by 3mm (1/8 inch) steel or alloy.

§  Lower Chain Guard: Toe Guard or “Shark Fin” required.


§  Clutch: Clutch must be of original type for engine used.


§  Clutch: Springs and friction plates may be substituted.


§  Clutch: Centrifugal assistance is prohibited.

§  No means of delaying clutch engagement is permitted.


Wheels and Tyres

§  Wheels: Standard wheels for model used required as a minimum. Aftermarket wheels produced for motorcycles permitted. Minimum diameter 431.8mm (17 inches).

§  Tyres: Treaded motorcycle road tyres with minimum tread depth of 1.6mm (1/16th inch) required.



  • Tyres: Slicks and tyres marked “Not for Highway Use” prohibited


§  Gear Shifting: Each individual shift must be controlled manually by the rider’s foot.


§  Gear Shifting: Ignition/fuel interruption to facilitate gear change permitted.

§  Ratio: Any final drive ratio permitted.



§  Gear Shifting: Air or electric gear change devices prohibited.

§  Automated Gear Shifting: Automated shifters and/or timer type shifting devices prohibited.




§  Brakes: OEM brakes for model used required.

§  Suspension: Stock operating suspensions and steering for model used required. Suspension must retain a minimum of 25mm (1 inch) downward suspension travel front and rear.

§  Steering: Steering dampers required


§  Ride Height: Lowering permitted. Motorcycles must have a minimum of 50mm (2”) ground clearance measured with the rider and relevant equipment in place and 15 psi in the rear tyre.

§  Suspension: External straps or devices used to limit the downward travel of forks permitted but must be recognizable as fit for purpose.

§  Swing Arm: Swing arm may be extended or replaced with aftermarket item to a maximum of 100mm (4”) longer than stock. Onus of proof on entrant. Bracing to be designed to limit torsional forces.

§  Wheelie Bars: Permitted but are required upon testing, to be capable of supporting the weight of the bike with the rider in position.



§  Swing Arm: Bolt-on swing arm extensions prohibited.


§  Helmet: Refer General Regulations. AS/NZS 1698 minimum requirement

§  Clothing: Full leather gloves, full leathers and full leather boots extending at least 150mm from the base of the heel required as minimum. Two-piece leathers may be used but must be fastened and joined prior to rider being placed in the hands of the starter.

§  Back protectors: Riders must wear a commercially manufactured back protector, which continuously covers the back area between the collar line and the base of the spine.

§  Lock wiring: Lock wiring or other means must be applied to secure all plugs or caps to restrict the discharge of any lubricating, cooling or hydraulic fluids.

§  Night Lighting: Required.

§  Towing: JDB Competitors can either be towed back to their paddock area by their parent or guardian after a run or be ridden back to the pits under the guidance of a lead escort i.e.: Parent or Track staff and helmets must be worn during this process.

§  Other Modifications or Additions: Any modification or addition deemed to be outside the spirit or scope of Junior Drag Bike is not permitted.


Self Starting

§  Self-Starting: Required.

§  Starting: Push starts are prohibited.

Technical Inspections

§  Technical Inspections: Mandatory for all Junior Drag Bikes.

§  IHRA Australia Log Book: Required.

§  Homologation Approval: All purpose-built drag racing motorcycles are required to have Homologation Approval from IHRA Australia Sub-committee prior to Technical Inspection.


Licence Requirements


§  Licence: IHRA Australia Junior Competition Licence required as minimum. The Junior Competition Licence is issued to applicants between the ages of 12 and 17 years old, for participation in Junior Drag Bike Eliminator.

§  Existing participants who turn 17 during a recognised series will be permitted to complete that series. A Medical Examination will be required at time of licence application.

§  Consent of the parent or legal guardian, who must be a current Full Member of IHRA Australia, is required.

§  Training: All riders must complete competency-based training from an accredited coach prior to rider applying for their Junior Competition Licence (JCL).

§  Minimum Weight: Minimum weight of 264 lbs (120kg) including bike, rider and apparel.

§  Minimum Height: Riders feet must reach firmly to the ground with all controls in comfortable reach.

§  JDB Crew Members: Junior Drag Bike Crew Members aged between 8 and 14 years must be supervised by an adult crew member.

Upon Rider turning 18 years of age any further competition is forbidden.
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