*STREET ET*

CLASS DESCRIPTION: Street E.T. is open to street legal bikes only. The class is run in an E.T. bracket racing format and is a great class for the novice racer to gain valuable racing experience.

DESIGNATION: The class designation is S/ET. All entrants must display bike number on both sides of their motorcycle.

FORMAT: This is an E.T. bracket class run on a .500 full tree. This is an all run field.

POINTS: Street E.T. is a non‐points class, but there is a “Tournament of Champions” race held at the Fall Finals each year for all the Street E.T. season winners to determine the Street E.T. World Champion.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes, and electronic throttle stops are prohibited.

LIGHTS: All motorcycles must have a functional OEM headlight or aftermarket headlight. All motorcycles must have a functional OEM tail light or aftermarket tail light. Flash lights are not permitted to be used as headlight or tail light.

CLUTCH: Clutch must be hand activated. Slider clutches are prohibited.

TIRES: DOT street tires only are permitted. All tires must have visible tread. DOT slicks are not permitted.

WHEELIE BARS: Wheelie bars are prohibited.

GENERAL SAFETY: All bikes must have a tethered kill. All bikes must have 2" of ground clearance. All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 

*PRO ET*

CLASS DESCRIPTION: Pro E.T. is open to all drag bikes and street bikes. The class is run in an E.T. bracket racing format and it gives bracket racers a chance to compete for larger purses.

DESIGNATION: The class designation is P/ET. All entrants must display bike number on both sides of their motorcycle.

FORMAT: This is an E.T. bracket class run on a .500 full tree. This is an all run field.

POINTS: Pro E.T. is a non‐points class, but there is a “Tournament of Champions” race held at the Fall Finals each year for all the Pro E.T. season winners to determine the Pro E.T. World Champion.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes and electronic throttle stops are permitted.

LIGHTS: Not required.

CLUTCH: Any style clutch permitted.

TIRES: DOT tires or any size slick is permitted.

WHEELIE BARS: Wheelie bars are permitted.

GENERAL SAFETY: All bikes must have a tethered kill. All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 

*STREET FIGHTER*

CLASS DESCRIPTION: Street Fighter is open to street legal bikes only. This class is designed for the a street bike racer that wants to run on an index. Street Fighter has a 9.50 index and the class is open to various combinations and several different size riders.

DESIGNATION: The class designation is SF. All entrants must display a bike number on both sides of their motorcycle.

FORMAT: This is a 9.50 Index class run on a .400 pro tree. This class is an all-run field. The #1 Qualifier will get the bye run in 1st round if there are an odd number of bikes. Pairings for all racers will be done in the tower by the computer system and paced on a pro ladder.

POINTS: This class will be a points class at all NHDRO events.

GENERAL: Each rider may only enter one bike in the Street Fighter class.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes, and electronic throttle stops are prohibited.

LIGHTS: All motorcycles must have a functional OEM headlight or aftermarket headlight. All motorcycles must have a functional OEM tail light or aftermarket tail light. Flashlights are not permitted to be used as a headlight or taillight.

CLUTCH: Clutch must be hand activated. Slider clutches are prohibited.

TIRES: DOT street tires only are permitted. All tires must have visible tread. DOT slicks are not permitted.

WHEELIE BARS: Wheelie bars are prohibited.

GENERAL SAFETY: All bikes must have a tethered kill. All bikes must have 2" of ground clearance. All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 
*CRAZY 8’S*

CLASS DESCRIPTION: Crazy 8’s is open to street legal bikes only. This class is designed for the advanced street bike racer that wants to run on an index. The name Crazy 8s was dubbed for the 8.88 index and the class is open to various combinations and several different size riders.

DESIGNATION: The class designation is C/8. All entrants must display a bike number on both sides of their motorcycle.

FORMAT: This is an 8.88 Index class run on a .400 pro tree. This class is an all-run field. The #1 Qualifier will get the bye run in 1st round if there are an odd number of bikes. Pairings for all racers will be done in the tower by the computer system and placed on a pro ladder.

POINTS: This class will be a points class at all NHDRO events.

GENERAL: Each rider may only enter one bike in the Crazy 8s class.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes, and electronic throttle stops are prohibited.

LIGHTS: All motorcycles must have a functional OEM headlight or aftermarket headlight. All motorcycles must have a functional OEM tail light or aftermarket tail light. Flashlights are not permitted to be used as a headlight or taillight.

CLUTCH: Clutch must be hand activated. Slider clutches are prohibited.

TIRES: DOT street tires only are permitted. All tires must have visible tread. DOT slicks are not permitted.

WHEELIE BARS: Wheelie bars are prohibited.

GENERAL SAFETY: All bikes must have a tethered kill. All bikes must have 2" of ground clearance. All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 

*SUPER COMP*

CLASS DESCRIPTION: This class is designed for the drag bikes and street bikes that want to run on an 8.90 index.

DESIGNATION: The class designation is SC. All entrants must display a bike number on both sides of their motorcycle.

FORMAT: This is an 8.90 Index class run on a .500 pro tree. This class is an all-run field. The #1 Qualifier will get the bye run in 1st round if there are an odd number of bikes. Pairings for all racers will be done in the tower by the computer system and paced on a ladder.

POINTS: This class will be a points class at all NHDRO events.

GENERAL: A rider may only run one bike in the Super Comp class.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes and electronic throttle stops are permitted.

TIRES: DOT tires or any size slick is permitted.

WHEELIE BARS: Wheelie bars are permitted.

GENERAL SAFETY: All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 

*TOP GAS*

CLASS DESCRIPTION: Top Gas is the quickest index class contested at NHDRO events. Top Gas is open to all drag bikes and street bikes. This class is designed for the drag bikes and street bikes that want to run on an 8.20 index.

DESIGNATION: The class designation is TG. All entrants must display a bike number on both sides of their motorcycle.

FORMAT: This is an 8.20 Index class run on a .400 pro tree. This class is an all-run field. The #1 Qualifier will get the bye run in 1st round if there are an odd number of bikes. Pairings for all racers will be done in the tower by the computer system and paced on a pro ladder.

POINTS: This class will be a points class at all NHDRO events.

GENERAL: A rider may only run one bike in the Top Gas class.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: 2-steps, delay boxes and electronic throttle stops are permitted.

TIRES: DOT tires or any size slick is permitted.

WHEELIE BARS: Wheelie bars are permitted.

GENERAL SAFETY: All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.

 

*PRO COMP*

CLASS DESCRIPTION: This class contests the wildest all‐out drag bikes in the sport today! Pro Mod is open to nitrous injected bikes, turbocharged bikes, and injected nitro bikes. The class has a diverse field of machines and is always a crowd favorite. These purpose‐built machines utilize state‐ of‐the‐art tube chassis designed to put massive amounts of horsepower to the ground and, with the aid of a wheelie bar, propel them through the 1/8 mile at astonishing speeds.

DESIGNATION: The class designation is P/C. All entrants must display a bike number on both sides of their motorcycle.

FORMAT: This is a heads‐up class running the eighth mile on a .400 pro tree. The class will qualify a 16‐bike field and place them on a pro ladder. There will also be a "B Class” for riders that qualified 17th – 32nd and they will be placed on a separate pro ladder. No alternates will be used in either class if a rider is broken.

POINTS: This class will be a points class at all NHDRO events.

NITROUS OXIDE: Entrants allowed to run nitrous oxide may use any style nitrous system with any number of solenoids or nozzles.

ENGINE: Production‐based motorcycle engines are allowed in all Pro Comp categories. In addition, approved aftermarket and automotive‐based engines are also allowed. To be considered for approval, aftermarket and automotive engines must have a maximum of 4 circular cylinders, a maximum of 4 valves per cylinder, must be readily available to the general public, and must receive approval for use prior to competing in a NHDRO event.

APPROVED AFTERMARKET ENGINES:

Aftermarket V‐Twins: Any 45° twin with pushrods is allowed
S&S: Billet 60° Pro Stock V‐Twin Buell
Puma Engineering: 4‐cylinder with factory head stud spacing (±2mm deviation in stud spacing from factory design)
General Motors: Ecotec 4‐cylinder‐Requires the use of production engine block and cylinder head castings

TURBOCHARGERS: Entrants are limited to one turbocharger. Entrants running under the 62.5mm or 70.9mm turbo designations are limited to a turbo with a maximum compressor inlet opening of 62.5mm or 70.9mm. NHDRO defines maximum turbo size as the maximum allowable diameter of the inlet housing at the point where the leading edge of the compressor wheel meets the inlet housing. All air entering the turbo must pass through this opening. No stepped inducer wheels permitted, the contour from the inducer to the exducer must be continuous without steps. The leading edge of inducer wheel may not exceed 62.5mm or 70.9mm, and must fit inside the 62.5mm or 70.9mm area of the inlet housing. The use of restrictor plates or stepped inlet housings in an effort to limit compressors with inducers larger than 62.5mm or 70.9mm is not acceptable. See chart at bottom of rulebook for different minimum weights and tire sizes based on turbo size.

INTERCOOLING: Combinations that are allowed the use of intercoolers may only use air‐to‐air intercoolers. Liquid‐to‐air intercoolers and cryogenic intercoolers are prohibited. Intercoolers may not be used in conjunction with methanol. Water injection is permitted.

SUPERCHARGERS: Entrants are limited to one supercharger. Supercharged entrants must utilize engine design where motor and transmission are inside same engine case.

INJECTED NITRO: Cannot be combined with a supercharger, turbocharger, or nitrous oxide.

FUEL: Any gasoline is allowed, as well as ethanol, methanol, and nitromethane in some categories. Nitrous oxide is not allowed in conjunction with nitromethane. Propylene oxide is not allowed in any category.

GASOLINE: NHDRO defines gasoline to be a complex mix of hydrocarbons, with a maximum of 25% oxygenates, and a maximum of 1% non‐ energetic anti‐knock and/or lubricant additives. Methanol and ethanol may not be used as oxygenates or additives.

NITROUS OXIDE: Entrants must run gasoline only.

SUPERCHARGED: May run gasoline, ethanol, methanol, or 50% maximum nitro fuel.

TURBOCHARGED: May run gasoline, ethanol, or methanol.

INJECTED NITRO: 100% nitro is permitted.

CARBURETORS: Any type carburetors are permitted.

FUEL INJECTION: Any type fuel injection system is permitted.

ENGINE MANAGEMENT SYSTEMS: Engine management systems (EMS), also known as Engine Control Units (ECU) may be either factory or aftermarket units. Factory ECUs may be swapped from other makes or models of bikes.

TECH INSPECTION: NHDRO tech may, at any time, on any motorcycle in competition, examine the maps, settings, data downloads, or any function of any factory or aftermarket EMS, piggyback or inline fuel injection controller, ignition system, data acquisition system, or any other electronic device on the motorcycle. Tech officials may conduct this examination in any manner, including performing the examination with a team representative as an observer only. It is the responsibility of the competitor to have ready, at all times, the required components to submit to this examination. This can include a laptop or PC, software, passwords, download cables, etc. It is also necessary that the competitor, or someone within the competitor’s team, is knowledgeable in the system being used, and is capable of assisting tech officials in navigating through any and all portions of the software. NHDRO tech may also impound any component of an ECU or data recording system for further examination either on‐ site or off‐site. Refusal to submit to any examination or failure to supply the required components for examination is grounds for disqualification and/or suspension.

ECUs may not detect and may not be activated by radio transmitters, infrared, laser or sonic devices, or any track position devices or beacons. Also, they may not wirelessly (ie radio, infrared, sonic. etc) transmit or receive information during the run to or from any source.

DATA ACQUISITION: Any electrical or mechanical device that may be used to activate, adjust, or tune any engine function based upon ride height, track position, front wheel speed, or front suspension conditions, is prohibited. Any sensors, including infrared or ultrasonic, that measure the track Christmas tree or timing system, the track surface, or any structure of the track facilities are prohibited. Any non‐contact sensor (sonic, infrared, radar, laser, etc) designed to detect or measure distance, position, or location is prohibited. The use of GPS, locator or position beacons, and locator or position transmitters is prohibited. Third wheel sensors, which is the use of any wheel or rolling device other than the normal front steering or rear drive wheel/tire to measure speed, distance, or track position, is prohibited.

BRAKES: Operational front and rear brakes are mandatory and must be in safe operating condition. Brake lines must be OEM type, braided steel hose or stainless steel line. Braided steel hose is highly recommended. Brake lines are to be routed and mounted properly to insure no contact with moving parts. Carbon fiber brake pads or disks are prohibited.

WHEELIE BARS: Wheelie bars are permitted.

GROUND CLEARANCE: All bikes must have a minimum of 2” ground clearance with rider sitting on bike, straight up perpendicular to ground (oil retention blankets may be removed to pass ground clearance test) All ground clearances are to be measured with the amount of air present in the rear tire at the conclusion of the run. No rider or team member is allowed to alter the pressure, measure the pressure, or otherwise make any contact with either tire valve stem until the conclusion of the post‐run technical inspection. If an entrant fails the ground clearance inspection and their rear tire pressure has dropped below 8lbs they will be allowed, upon the tech director’s approval, to raise the rear tire to 8lbs and reattempt the ground clearance test.

GENERAL SAFETY: All riders must have full leathers (zipped together leathers are recommended and may be mandatory in future). All riders must have a SNELL 95 or higher full‐face helmet with shield, leathers gloves, and shoes above the ankle. All motorcycles and riders must pass IHRA safety inspection. Ballistic blankets are recommended but are not required. Tether kill switches required on all entrants. Kill switch, when activated, must disable ignition, fuel pump(s) and nitrous system solenoids.

RULE REVISIONS: In order to maintain a level playing field, NHDRO will monitor the performance numbers of the numerous combinations and power adders found in this class. From time to time, it may be necessary to adjust the minimum weights to help promote class parity. Any rule revisions deemed necessary by NHDRO would be officially posted on the NHDRO website a minimum of 14 days prior to the event in which they become effective (the rulebook on the NHDRO website on the day of the event is in full effect). Any rule revision deemed necessary for the reasons of safety may be made at any time, even after the start of an event, and may be made effective immediately.

MINIMUM WEIGHT: All weights include both the bike and rider, and will be taken at the conclusion of the run.

Designation	Power Adder	Engine Type	Displacement	Fuel	Max Tire	Min Weight
PM/A	Naturally Aspirated	4‐cylinder or V‐Twin	Any Size	Gas Only	10” wide	550 lbs.
PM/NP	Nitrous Oxide	4‐cylinder (Plain Bearing)	1800cc Max	Gas Only	11” wide	585 lbs.
PM/NR	Nitrous Oxide	4‐cylinder (Roller Bearing)	1800cc Max	Gas Only	11” wide	625 lbs.
PM/VT	Nitrous Oxide	V‐Twin	2640cc Max	Gas Only	11” wide	625 lbs.
PM/TA	62.5mm Max Turbo. Nitrous & Intercoolers prohibited.	4‐cylinder or V‐Twin	Any Size	Gas Only	11” wide	625 lbs.
PM/TB	70.9 mm Max Turbo. Intercooler ok. Nitrous prohibited.	4‐cylinder or V‐Twin	Any Size	Gas / Methanol	13” wide	700 lbs.
PM/TC	70.9 mm Max Turbo. Intercooler ok. Nitrous ok.	4‐cylinder or V‐Twin	Any Size	Gas / Methanol	13” wide	740 lbs.
PM/S	Supercharger	4‐cylinder or V‐Twin	Any Size	Gas / Methanol / 50% Nitro	12” wide	660 lbs.
PM/IN	Injected Nitro	4‐cylinder or V‐Twin	Any Size	Gas / Methanol / 100% Nitro	14” wide	720 lbs.

 

*PRO STREET*

CLASS DESCRIPTION: This class contests the ultimate in street‐legal motorcycles. Created to legitimize illicit street racing, Pro Street is reserved for stock‐appearing motorcycles with unlimited engine modifications. All bikes must be street legal with VIN tag, utilize a hand clutch, and be self‐ starting with motorcycle engines only.

DESIGNATION: The class designation is PST. All entrants must display a bike number on both sides of their motorcycle by their bike number.

FORMAT: Pro Street is a heads‐up class contested on the quarter mile and utilizing a .400 pro tree. The class will qualify a 16‐bike field and place them on a pro ladder. There will also be a "B Class” for riders that qualified 17th – 32nd and they will be placed on a separate pro ladder. No alternates will be used in either class if a rider is broken.

POINTS: This class will be a points class at all NHDRO events.

BIG‐BORE BIKES: Production big‐bore bikes are permitted a single power adder.

LITER‐CLASS BIKES: In order to entice the use of the highly popular current class of late‐model liter bikes, approved motorcycles originally produced as 1000cc displacement sport bikes are permitted to compete with a lower minimum weight. Only the latest lightweight, high‐tech import offerings, with a maximum production size of 1000cc, will be permitted to race under this designation, and each model must be approved for use by NHDRO. Currently, the following 2001 or newer models are approved for use:

BMW:              S1000RR
HONDA:           CBR929RR, CBR954RR, and CBR1000RR KAWASAKI: ZX‐9 and ZX‐10
SUZUKI:           GSXR1000
YAMAHA:        YZF‐R1

ENGINE: Only production‐based motorcycle engines are permitted, and must utilize factory cases and cylinder heads. Aftermarket cylinder blocks are permitted. Any internal modifications are permitted. Nitrous oxide may not be used in conjunction with any turbocharged entrants. Air or electric shifters permitted.

NITROUS OXIDE: Entrants allowed to run nitrous oxide may use any style nitrous system with any number of solenoids or nozzles.

TURBOCHARGERS: Entrants are limited to one turbo with a maximum turbo inlet opening of 62.5mm. NHDRO defines maximum turbo size as the maximum allowable diameter of the inlet housing at the point where the leading edge of the compressor wheel meets the inlet housing. All air entering the turbo must pass through this opening. No stepped inducer wheels permitted, the contour from the inducer to the exducer must be continuous without steps. The leading edge of inducer wheel may not exceed 62.5mm, and must fit inside the 62.5mm area of the inlet housing. The use of restrictor plates or stepped inlet housings in an effort to limit compressors with inducers larger than 62.5mm is not acceptable.

INLET COOLING: Any type of inter‐cooling permissible. Turbocharged entrants that are prohibited from the use of nitrous may not use nitrous as cryogenic cooling source.

Entrants utilizing water injection must have the water tank mounted in a manner to allow tech to easily inspect its contents. Absolutely no substance other than water is permitted to be in the tank.

INTERCOOLER MOUNTING: Any part of the turbo or induction system may be mounted within the original bodywork/frame envelope in any available location. Components mounted outside of the bodywork are limited to an area no higher than 24 inches above the ground, 18 inches to either side of the bike centerline, and no more than 3 inches forward of the front axle.

SUPERCHARGERS: Any style engine‐driven supercharger is allowed. Supercharged entrants shall follow the nitrous‐injection rules. Supercharging and nitrous may not be used in combination.

CLUTCH: All clutch systems must be approved by NHDRO for use in this class. Each interested manufacturer or team must submit sample parts for approval a minimum of 60‐days prior to any event in which it desires approval eligibility. No pneumatic, electric, or hydraulic clutch engagement or activation systems are permitted.

ALL BIKES: Slider clutches prohibited. Clutch engagement and disengagement must be controlled by conventional cable or hydraulic‐actuated clutch lever. With the engine off and the bike in gear, the clutch must have sufficient engagement force to prevent the bike from being rolled without either sliding the rear tire or rotating the engine. With the brakes locked or the bike otherwise blocked from rolling, the clutch system must have sufficient engagement force at idle to kill the engine if the clutch lever is released. Idle may be set between 1000‐2500rpm for this test. The use of ECU mapping or electrical system functions to simulate the positive results of this test is not allowed, engine kill must be as a direct result of clutch engagement drag. *NHDRO will allow slider clutches on nitrous bikes.

TRANSMISSIONS: All entrants must utilize an OEM‐style shift drum and transmission.

TURBOCHARGED: Automatic transmissions prohibited. No transmission that could allow override‐style shifting is permitted. No components may be used that are designed to allow the transmission to be simultaneously engaged in more than one gear. This includes, but not exclusive to, windowed shift drums, split forks, split gears, split fork slider rings, gear or fork detent springs, etc.

NITROUS INJECTED: Automatic transmissions permitted with a weight penalty.

TRIPLE CLAMPS: The steering stem offset on top and bottom triple clamps must be equal. Front axle offset may not be less than 1/2‐inches. The use of triple clamps, steering stems, stem bearings, offset bearing races, or any other components designed to increase or decrease the rake is prohibited. Axle must be in the center of the forks. Triple clamps can be made of a material other than aluminum only after NHDRO approval of concept. Bottom of lower triple tree cannot be higher (must be flush or lower) than webbing of lower steering neck.

FRAME: Stock OEM frames required. No modifications to any portion of frame permitted, unless specifically noted.

ALLOWABLE MODIFICATIONS:

ALL BIKES: Frames may be polished, chromed, painted, powder coated, or otherwise cosmetically altered, as long as such modifications do not remove substantial material or weaken the frame. No braces, gussets, or crossbars may be removed, unless specifically listed. Additional braces, gussets, or crossbars may be added, as long as they do not weaken the frame in any manner.

Small accessory brackets, tabs, mounts, etc., using fasteners no larger than 5/16” (8mm) may be removed, relocated, or modified. New accessory mounts may be installed, and new mounting holes may be drilled into the frame, as long as the hole size does not exceed 5/16” (8mm). An excessive number of mounting holes will be considered lightening of the frame, and is not permitted. Exhaust mounting brackets, center‐stand, and side‐stand brackets, regardless of fastener size, may be removed as long as doing so does not weaken the frame.

On turbocharged entrants, steering heads must remain stock, with the exception of the lower steering stem bearing race area. The bottom of the steering head may be re‐machined or removed and replaced in order to increase the clearance between the front tire and the bottom triple clamp, a technique commonly referred to as “short necking”. If short‐necking has been performed, the new bearing race cup must use the factory bearing race, and may not be located more than 1.00 inches above the original bottom webbing of the steering neck. The replaced or modified bearing race cup must be located along the same axis as the original location, i.e., the rake of the steering stem may not be altered during this modification. No other material beyond that reasonably necessary to perform the short‐neck modification may be removed from the steering neck casting, with the exception of removal or modification of the steering stops and/or the headlight/fairing mount. For non‐turbocharged entrants, frames may be altered in order to increase the rake. No de‐raking of frames will be permitted. Location of bottom triple clamp must be in the same general location as the legal modifications permitted for turbocharged entrants. Seat rails/sub‐frames may be modified or relocated. Mounting tabs or brackets for these items may be modified or relocated as well.

Rear suspension mounts including shock mount and rising rate linkage mounts may be relocated. However, due to the extreme loads and potential safety issues, modifications to these components will be heavily scrutinized.

On turbocharged entrants, swingarm pivot mounts may not be modified. Swingarm pivot centerline cannot be moved in any manner, including offset bushings, plates, etc. Proper design, welding, and bracing are crucial in these areas. Non‐turbocharged entrants are permitted to relocate the swingarm pivot axle up to 2” from its factory location. Engine mounting tabs and brackets may not be modified. Bolt‐on engine mounts may be replaced, but must maintain the same mounting dimensions as the factory mounts. Engine relocation in any manner is not permitted.

HONDA BLACKBIRD: The round tubular cross‐brace, located directly behind the steering stem, may be removed. Upper rear sub‐frame mount may be removed. It may be cut off flush with the top of the factory frame spar, but no farther.

KAWASAKI ZX‐12, ZX‐14: Airbox inlets may be welded shut, or modified for better sealing with turbo dump pipe, as long as these openings are not enlarged. Access panels for throttle body/airbox connectors may be modified, as well as the mounting area for the connectors. These modifications may not weaken the frame. Opening for turbo pop‐off valve may be cut in airbox area of frame as needed, as well as mounts or bungs for air sensors.

SUZUKI GSXR (EARLY MODELS): 1986‐1987 750 and 1986‐1988 1100 models may remove the square tubular cross‐brace located generally above the carburetors.

Late‐model liquid‐cooled models, factory‐equipped with engine mounts connecting between the cylinder head and the upper frame spar, are not required to use these mounts. The mounting tabs for these mounts may be removed from the frame.

SUZUKI HAYABUSA: The round tubular cross‐brace, located directly behind the steering stem, may be removed. Upper rear sub‐frame mount may be removed. It may be cut off flush with the top of the factory frame spar, but no farther.

SUZUKI GS & KAWASAKI KZ/Z1: Frames may be modified for a backbone fuel cell. Backbone cell may not be used to hold any fuel or other liquids.

WHEELIE BARS: Wheelie bars are prohibited.

SEAT: Minimum seat height, with rider in position, seat compressed and 8 psi in rear tire, is measured from lowest point of seating position to the ground. All entrants must have a minimum seat height of 22”.

TIRES: DOT‐approved motorcycle street tires only. Slicks are prohibited.

FUEL: Any gasoline is allowed. Nitromethane, propylene oxide, ethanol, and methanol are not allowed.

GASOLINE: NHDRO defines gasoline to be a complex mix of hydrocarbons, with a maximum of 25% oxygenates, and a maximum of 1% non‐ energetic anti‐knock and/or lubricant additives. Methanol and ethanol may not be used as oxygenates or additives.

BODY: All main body parts including upper fairing, side fairings, fuel tank, and tail section must have stock appearance and shape (i.e., no one piece bodies or tank shell, unless originally equipped). Front fenders are required and must be manufactured of plastic, fiberglass, or carbon composite. All bodywork must match the type of frame being used (i.e., you cannot put GSXR bodywork on a GS frame, or ZX‐14 bodywork on a ZX‐10). Bodywork may be updated or backdated to later or earlier model bodywork if the same type frame is used for those models. Tail section or rear fender must extend past the rear axle. Replacement parts are permitted, but must retain the shape of the stock parts they replace. Altering of stock body shapes must be approved by NHDRO. To allow access to nitrous bottles, all nitrous bikes must have thumb (butterfly) body fasteners on any aftermarket body pieces that cover bottle to allow removal of panel or section by hand without the use of tools.

FRONT FAIRING: No portion of the front fairing or headlight may be mounted farther forward than 3 inches past the forward most part of the front tire.

FUEL TANKS: Manufacturer name must appear on both sides of gas tank. Alterations of factory gas tanks are limited to sloping at rear of tank. Aftermarket fuel tanks are limited to NHDRO approved manufacturers and part numbers only. In order for a tank to be legal, it must be commercially available, at a fair market price, to anyone desiring to purchase one. Manufacturer or distributor must be able to maintain availability at all times, and must be able to make delivery within 30 days of order. Manufacturer or distributor has the right to demand full pre‐payment, including any shipping charges, before considering an order to be completed. Companies desiring to produce production tanks for this application may submit tank designs for approval. For further questions or inquiries, contact NHDRO technical department.

ALUMINUM FUEL TANKS: Nitrous injected bikes and bikes originally equipped with tank shells are allowed to run an aluminum fuel tank. Tanks must have an accessible fuel filler cap in a similar location to the approved tanks with an opening and fill tube large enough to fill with a conventional gas pump nozzle. The outer tank shell must be from the approved aftermarket tank list in the tank shell version. The aluminum cell must be mounted under the tank shell and above the engine. Fuel cell may not be mounted in any location that is not representative of the OEM fuel tank location.

CURRENT APPROVED AFTERMARKET TANKS:

Manufacturer	Model Bike	Part Number
Catalyst Racing Composites	Hayabusa	BUSOTK99, BUPSTK99, BUPS2TK99, BUPS3TK08, VELOCITYTANK06, VELOCITYTANK08
Del’s Performance Cycles	Hayabusa	DPCBUSTSHELL
Catalyst Racing Composites	GSXR 1000	GSXR1LTK05, GSXR1SOTK05, GSXR1LTK07, GSXR1GTT07
Catalyst Racing Composites	GSXR 1100	GSXR11LTK89
Catalyst Racing Composites	ZX‐14	ZX14PSTK06, ZX14SOTK06
Catalyst Racing Composites	ZX‐12	ZX12PSTK02
Catalyst Racing Composites	ZX‐10	ZX10LTK04, ZX10GTK04
Air‐Tech Streamlining	CBR 1000 RR	2CBR17M

TAIL SECTIONS: Seat location will be determined by a minimum distance of 29.5‐inches measured from the centerline of the steering stem to the back of the seat, including padding, at the bottom most point measured at a 90 degree angle to the ground. Approval of all parts will be limited to 30‐days prior to an event. Photos of parts installed on the exact bike must be submitted for approval.

STARTING SYSTEMS: All engines must be self‐starting and utilize OEM‐style starting systems. No push or roller starts. All systems must be on‐board, no external devices may be used to assist the batteries or starter systems.

LAUNCH CONTROL: The use of 2‐steps and other launch control devices are legal for all entrants.

ENGINE MANAGEMENT SYSTEMS: Engine management systems (EMS), also known as Engine Control Units (ECU) may be either factory or aftermarket units. Factory ECUs may be swapped from other makes or models of bikes.

TECH INSPECTION: NHDRO tech may, at any time, on any motorcycle in competition, examine the maps, settings, data downloads, or any function of any factory or aftermarket EMS, piggyback or inline fuel injection controller, ignition system, data acquisition system, or any other electronic device on the motorcycle. Tech officials may conduct this examination in any manner, including performing the examination with a team representative as an observer only. It is the responsibility of the competitor to have ready, at all times, the required components to submit to this examination. This can include a laptop or PC, software, passwords, download cables, etc. It is also necessary that the competitor, or someone within the competitor’s team, is knowledgeable in the system being used, and is capable of assisting tech officials in navigating through any and all portions of the software. NHDRO tech may also impound any component of an ECU or data recording system for further examination either on‐ site or off‐site. Refusal to submit to any examination or failure to supply the required components for examination is grounds for disqualification and/or suspension.

ECUs may not detect and may not be activated by radio transmitters, infrared, laser or sonic devices, or any track position devices or beacons. Also, they may not wirelessly (ie radio, infrared, sonic. etc) transmit or receive information during the run to or from any source.

DATA ACQUISITION: Any electrical or mechanical device that may be used to activate, adjust, or tune any engine function based upon ride height, track position, front wheel speed, or front suspension conditions, is prohibited. Any sensors, including infrared or ultrasonic, that measure the track Christmas tree or timing system, the track surface, or any structure of the track facilities are prohibited. Any non‐contact sensor (sonic, infrared, radar, laser, etc) designed to detect or measure distance, position, or location is prohibited. The use of GPS, locator or position beacons, and locator or position transmitters is prohibited. Third wheel sensors, which is the use of any wheel or rolling device other than the normal front steering or rear drive wheel/tire to measure speed, distance, or track position, is prohibited. Any sensors measuring front wheel/tire speed, position, temperature, or pressure are prohibited. Any sensor measuring any function of the suspension including travel, distance, position, or external or internal fork or shock conditions are prohibited. Any mechanical, infrared, ultrasonic, or other type sensor that measures ride height is prohibited. In addition to standard electronic data measurement sensors, any electrical or mechanical device that may be used to activate, adjust, or tune any engine function based upon ride height, track position, front wheel speed, or suspension conditions, is prohibited.

ELECTRICAL: Functional charging system, head and taillight w/ brake light, and kill switch required. Headlight and taillight must be retained in stock locations. Turn indicators optional. Headlight is required to be on during all qualifying and eliminations runs. In the event of failure of either the charging system or the lighting system, the tech department will allow repairs to be made prior to the next round of competition. This courtesy repair opportunity is only allowed once per event, per system. Failure by the rider or crew member to activate either the charging or lighting system is considered to be a system failure. Any failure of either system for the second time in the same event will result in an automatic disqualification. Auto shifters are prohibited.

HEADLIGHTS: Factory headlight systems matching the bike model must be used. All of the original factory glass or plastic lenses must be used, may not be painted or wrapped (reasonable transparent tinting permitted) and must be mounted in the original location in the front fairing (or headlight bucket on non‐faired bikes). Non‐fairing bikes must have the headlight bucket mounted in factory location. All components which are part of the original beam generating and reflecting system, and are visible from the outside of the bodywork, must be retained, and may not be modified in any manner visible from the outside. These components include reflectors, secondary lenses, diffusers, bulb sockets, and bulbs. All such components of both the low‐beam and high‐beam systems must be retained, even if that system is not in use. Required components may be mounted in any suitable manner. Any modification of the mounts, housing, or non‐visible areas of the lenses, reflectors, and other required components is permitted. However, lighting system must be enclosed to prevent the escape of light from behind the fairing or bucket. During competition, either the low‐beam or high‐beam lights must be on at all times. Bikes factory‐equipped with multiple‐light systems (i.e. left and right bulbs) must burn both the left and right bulbs of the system being used. Unused bulbs do not need to be electrically functional, and a high/low switching system is not required.

TAILLIGHTS: All entrants must have a functioning taillight system, with operational tail and brake lights. Factory taillights are highly recommended. Non‐factory tail lights must emit red light, and must be sufficiently bright to be reasonably visible.

BALLAST: Ballast is defined as any component attached to any part of the motorcycle, whose purpose is to add weight to the motorcycle. Any component, regardless of weight, which serves a structural, mechanical and/or performance enhancing function, is not considered to be ballast. (i.e., as a general reference, if the component in question can be removed without affecting any functions of the motorcycle, or decreasing structural integrity of the motorcycle, it is considered ballast). NHDRO does, however, reserve the right to deem any non‐ballast component to be illegal, if its excessive weight or design creates a safety hazard, or if its construction or implementation is of an unprofessional appearance. Ballast may not be mounted to any bodywork or other plastic or composite components, nor may it be mounted to any part of the riders’ body or equipment. Liquid or loose ballast (i.e., water, sand, rock, shot bags, etc.) is prohibited.

BALLAST MOUNTING: Ballast may be mounted to any portion of the frame, swingarm, seat mounts, rear sub‐frame, fairing brackets, or any suitable structural component with sufficient strength to safely support the weight of the ballast during the run. Ballast mounting must be sufficiently strong to support the weight of the ballast, as determined by the tech director. All ballast must be mounted within the outer dimensions of the frame, rear sub‐frame, swingarm, or bodywork. Ballast may not be mounted to any part of the exhaust system.

CAPTURED BALLAST: Captured ballast is any material or component captured or contained within or around another component without the use of mounting fasteners. This form of attachment is still considered to be “mounted”. This would include pourable ballast, such as epoxy or melted lead, inside of a tube or cavity. It would also include, but not be limited to, other ballast material contained within welded, clamped, or mechanically fastened components such as inside welded frame or swingarm components, inside a fork assembly, or press‐fit into a fork slider tube.

FRONT SUSPENSION BALLAST: No ballast may be mounted to any portion of the front suspension, brake system, fender system, or rotating assembly. Unless specified otherwise, no parts of the front suspension, brake system, or fender system may be remanufactured from exotic heavy materials, including tungsten steel, HD‐17, or Mallory metal [see EXOTIC HEAVY MATERIALS]. Front suspension components other than the fork leg assemblies and front wheel assembly (this includes triple clamps, clip‐on’s, fender mounts, brake calipers and hangers, etc.) may be remanufactured from any legal materials, but must be constructed to dimensions reasonable for the application, with hardware reasonably‐sized for the application. Whenever possible, OEM components will be used as a reference when determining what are appropriate sizes and dimensions. Lightening holes, gun‐drilling, and other weight‐saving techniques utilized on the OEM components may be deleted. Pre‐approval of custom or aftermarket components is highly recommended. The tech staff has final decision on all front suspension component matters, and will be closely monitoring the use of these components.

EXOTIC HEAVY MATERIALS: NHDRO defines an exotic heavy material as any material with a density higher than 8.1 grams per cubic centimeter. With the exception of components considered to be part of the fork or front wheel assemblies, no front end components may be manufactured from an exotic material.

WHEELS: Cast wheels must have a 180mm or greater width tire. Wheels 6.75 inches wide or wider must have bead‐lock unless utilizing Mickey Thompson MCR2 or NHDRO approved tire. Bead‐lock highly recommended on all rear wheels. 16‐inch minimum diameter front wheels are permitted.

MAXIMUM FRONT WHEEL WEIGHT: Front wheel and brake rotor components may be manufactured from any material. Total weight of front wheel rotating assembly, including tire, rotor, bearings, etc cannot exceed 29 lbs. Inner bearing spacers and any axle spacers not removable without the use of tools are included in the wheel weight. Any bearing or axle spacers removable by hand will be included in the front axle weight [see FRONT AXLES].

FRONT AXLES: Front axle assemblies may be remanufactured or replaced with aftermarket components. Any aftermarket axle must have a dimple or hole in the center of the axle on each side to aid in wheelbase measurements. No part of the axle or nut may protrude more than .75" beyond the outside of the fork legs. No remanufactured or replacement part of the axle, axle nut, or spacers may exceed 1.50" in diameter. Unmodified OEM parts larger than 1.50” are acceptable. The total weight of the front axle assembly, including spacers, nuts, washers, etc. may not exceed 5 lbs total weight. This weight shall include all OEM and non‐OEM parts. The use of lead or exotic heavy materials is not allowed on any axle components.

FRONT SUSPENSION: Rigid forks prohibited. Hydraulic‐dampened tube type only, with a minimum tube diameter of 34mm. Front suspension must have sufficient hydraulic damping to allow safe operation. Modifications to existing OEM or aftermarket forks which completely remove or otherwise defeat the function of the damping systems is not acceptable. The design of custom forks must include sufficient damping for the safe operation of the motorcycle under race conditions. All entrants must have a minimum of 1” travel in the front forks, with sufficient clearance around the fender, fairing, headlight, exhaust, etc. to allow the forks, fender, and wheel/brake assembly to safely move across the full range of fork travel at any steering angle. Forks must have enough front spring force to keep forks extended at least .50” above compression bump stop with bike sitting level and rider seated in riding position. Travel is measured from the compression bump stop to the rebound bump stop. NOTE: Having 1” of exposed fork slider DOES NOT guarantee that 1” of travel exists. No more than 1.5” of upper tube (2” on inverted forks) may be exposed above top triple clamp or clip‐on, whichever is higher.

MAXIMUM FORK WEIGHT: Fork components may be manufactured of any materials. Fork weight includes all internal and external components of the fork, including the fork oil. Weight does not include axles, axle spacers or hardware, brakes, brake brackets or hardware, fenders, fender mounts or hardware, or any other components mounted external of the fork. Applicable fork weight is determined by the year model of the frame, and not the year model of the forks.

Maximum Weight per Side:
1999 & Newer Models:           9.0 lbs
1998 & Older Models:           12.5 lbs

BRAKES: Operational front and rear brakes are mandatory and must be in safe operating condition. Brake lines must be OEM type or braided steel hose or stainless steel line. Braided steel hose is highly recommended. Brake lines are to be routed and mounted properly to insure no contact with moving parts. Carbon fiber brake pads or disks are prohibited.

GROUND CLEARANCE: All bikes must have a minimum of 3” ground clearance with rider sitting on bike, straight up perpendicular to the ground. Belly pans and oil retention blankets may be removed to pass ground clearance test. Bikes with a sealed pan or oil retention blanket must have a minimum of 2.5” of ground clearance with the blanket or belly pan in place. All ground clearances are to be measured with the amount of air present in the rear tire at the conclusion of the run. No rider or team member is allowed to alter the pressure, measure the pressure, or otherwise make any contact with either tire valve stem until the conclusion of the post‐run technical inspection. If an entrant fails the ground clearance inspection and their rear tire pressure has dropped below 8lbs they will be allowed, upon the tech director’s approval, to raise the rear tire to 8lbs and reattempt the ground clearance test.

SEALED BELLY PANS: One‐piece lower bodywork designed to catch all fluids following a catastrophic engine failure are encouraged. To be considered a sealed pan, the lower section must be capable of holding a minimum of 5 quarts of liquid with no leakage while mounted on the motorcycle. Entrants employing a sealed lower bodywork section may remove this bodywork to pass the minimum ground clearance. Any parts removed to pass ground clearance must be of a semi‐flexible material such as fiberglass or carbon fiber. With the sealed belly pan removed, all non‐rigid parts, including oil pans, brackets, hangers, and supports, must still pass the minimum 3” ground clearance. All sealed pan designs must be approved by the NHDRO technical department prior to use.

GENERAL SAFETY: All riders must have full leathers (zipped together leathers are recommended and may be mandatory in future). All riders must have a SNELL 95 or higher full‐face helmet with shield, leathers gloves, and shoes above the ankle. All motorcycles and riders must pass IHRA safety inspection. Ballistic blankets are recommended but are not required. Tether kill switches required on all entrants. Kill switch, when activated, must disable ignition, fuel pump(s) and nitrous system solenoids.

RULE REVISIONS: In order to maintain a level playing field, NHDRO will monitor the performance numbers of the numerous combinations and power adders found in this class. From time to time, it may be necessary to adjust the minimum weights, ground clearance, and wheelbase to help promote class parity. Any rule revisions deemed necessary by NHDRO would be officially posted on the NHDRO website a minimum of 14 days prior to the event in which they become effective (the rulebook on the NHDRO website on the day of the event is in full effect). Any rule revision deemed necessary for the reasons of safety may be made at any time, even after the start of an event, and may be made effective immediately.

MINIMUM WEIGHT: All weights include both the bike and rider, and will be taken at the conclusion of the run.

 

Power Adder	Engine Platform	Displacement	Transmission	68” Wheelbase	69” Wheelbase	70” Wheelbase
Turbo	Big‐Bore	1370cc Max	No Auto	650 lbs	675 lbs	700 lbs
Turbo	Big‐Bore	1371cc ‐ 1450cc Max	No Auto	675 lbs	700 lbs	725 lbs
Turbo	Original Liter	1125cc Max	No Auto	530 lbs	555 lbs	580 lbs

 

Power Adder	Engine Platform	Displacement	Transmission	68” Wheelbase	69” Wheelbase	70” Wheelbase
Nitrous	Big‐Bore	1660cc Max	Auto ok	510 lbs	535 lbs	560 lbs
Nitrous	Original Liter	Unlimited	Auto ok	375 lbs	400 lbs	425 lbs
• Big bore bikes with auto transmission: Add 30 lbs.

 

*GRUDGE*

CLASS DESCRIPTION: This class is designed for the ultimate in grudge bike racing.

DESIGNATION: None.

FORMAT: Class is run on a .400 pro tree. Each opponent sets up his or her own races.

POINTS: This is not a points class.

BRAKES: Front brakes are required.

CHAIN GUARDS: Chain guards are required on all entries.

ELECTRICAL: Anything goes.

LIGHTS: Not required.

CLUTCH: Any style clutch permitted.

TIRES: DOT tires or any size slick is permitted.

WHEELIE BARS: Wheelie bars are permitted.

GROUND CLEARANCE: All bikes must have a minimum of 2” ground clearance with rider sitting on bike, straight up perpendicular to the ground.

GENERAL SAFETY: All riders must have a SNELL 95 or higher full face helmet, shoes above the ankle, leather gloves, and a leather jacket. Any rider running faster than 10.99 must also have leather pants. Pants and jacket are not required to be zipped together. Nylon or textile jackets and pants are not permitted, even if they have pads. All jackets and pants must be made of 100% leather.