SECTION 14óDIRT TRACK

14.1 RIDER ELIGIBILITY/EQUIPMENT:

a) Competitors must demonstrate that they can ride up to Junior level, or be vouched for in writing by an AHRMA-accredited dirt track rider.

b) Riders who have raced as a professional in the preceding 12 months may not compete in AHRMA dirt track events, to protect AHRMA amateur riders. Pro-Sport/Pro-Am riders and Division 2 and Division 3 speedway riders are eligible to compete.

c) Any rider entered in an AHRMA Novice class event may not compete in any other AHRMA classes that day.

d) The minimum rider age is 18.

e) Riders must wear full leathers on track a half-mile in length or longer. Leathers are strongly recommended for all types of dirt track races. The use of back protectors is strongly recommended. Boots covering at least the top of the ankle and gloves are required of all competitors. Helmets must be full-facial type and certified by the manufacturer by having a sticker affixed to the helmet stating the helmet meets or exceeds the Snell M2000 standard or other applicable standards listed in rule 3.3.14.

14.2 FLAT TRACK CLASSES

14.2.1 DINOSAUR: 1951 and earlier, 500cc OHV or 750cc sidevalve.

14.2.2 CLASSIC 250: 1967 and earlier and approved-design machines up to 250cc. The following machines are eligible:

Aermacchi (H-D Sprint), all 250cc

AJS Stormer 250

BSA C15, B25, all

Bultaco round-barrel, round-case four- and five-speed (engine & frame serial # prefix 3-45, 63, 66, 67)

CZ twin-port

Ducati

Eso

Greeves Challenger

Honda CB/CL72

Husqvarna "bolt-together" pre-í68 only (no Sportsman components)

Jawa twin-port

Kawasaki A1

Maico, with OEM iron barrel

Matchless G2

Montesa four-speed (Serial # prefix 02-18, 23-25, 33, 53 small barrel)

Ossa four-speed (no DMR chassis) (Serial #153000-155999, #250000-262999 and #280000-280999)

Parilla

Suzuki T20 X6 (no T250s)

Triumph Tiger 70, Cub, TR25W

Villiers-powered machines (Greeves, Dot, James, Norman, etc.)

Yamaha twins up through TD1C

a) Two-strokes are limited to 32mm carburetors on singles, 28mm twins, except that Ossas may run OEM 33mm IRZ carburetors.

14.2.3 CLASSIC 500/750: 1967 and earlier and approved-design machines up to 500cc, including 750cc sidevalve bikes. Eligible machines are:

Aermacchi 350 (H-D Sprint), all

Ariel 500 singles or twins, VB 600 sidevalve single

AJS/Matchless four-stroke singles, twins

AJS Stormer 370/410

BSA A7, A50, B31/32/33/34, Gold Star, B40, B44, M20, M21

Bultaco El Bandido, Montadero (Serial # prefix 17, 18, 50, 51, 61, 70 and 81)

CZ 360 twin-port

Ducati 350, 450

Greeves 360 Challenger

Harley-Davidson KR

Honda CL77, CB450 Black Bomber four-speed (serial #CB4501000001-CB4502999999) utilizing torsion-bar valve control system

Husqvarna 360 "bolt-together" pre-í68 only (no Sportsman components)

Maico 360 oval barrel

Montesa 360 Cappra four-speed (Serial # prefix 36, 46 and 66)

Norton 500 singles, twins, 600 sidevalves

Royal-Enfield singles, twins (including new-production Enfield singles)

Triumph pre-unit or unit twins

Velocette

Yamaha Big Bear Scrambler, Catalina

14.2.4 SPORTSMAN 250: 1974 and earlier machines up to 250cc, including like-design models. Eligible machines include:

Bultaco, all

Can-Am 175; all 250cc machines must run in Seventies Two-Stroke

CZ single-port

Greeves Griffon

Harley-Davidson two-strokes; MX250-based machines must run in Seventies Two-Stroke

Honda CR250M, XL250

Husqvarna, pre-reed-valve, plus '74 Mag 250CR

Kawasaki A1R, Greenstreak 238, pre-reed-valve KX250 (engine number K2E900001-K2E911400 only)

Maico square-barrel and radial, up to GP

Montesa, all five-speed

Ossa four-speed w/DMR frame, all five-speed

Suzuki T250, TM250, TS250 all

Yamaha DT singles (engine # prefix DT1, 438 or 450), MX250 (#364), YZ250 (#431 or 483)

Yamaha air-cooled twins up through RD250 or TD3B

a) Yamaha singles with engine number prefixes 509, 1W3, 2K7 or later are prohibited. See Seventies Two-Stroke.

Note: Can-Am 250s must run in Seventies Two-Stroke.

14.2.5 SPORTSMAN 600: 1974 and earlier machines manufactured as 251-600cc, including like-design models. Eligible machines include:

Bultaco, all 350, 360, 370 five-speed

CZ single-port 360, 380

Greeves Griffon 380

Honda CB350, CB450, 500T

Kawasaki Bighorn 350, F12M, KX450, 1975-'76 KX400

Maico square-barrel and radial, up to GP

Suzuki T350, TM400, TS400, T500

Yamaha RT singles (Engine # prefix RT1), DT360 (#446), MX360 (#365), YZ360 (#432 or 484), SC500 (#363)

Yamaha air-cooled twins TR2, TR3, R5, RD350, TX500

a) Honda XL350s with center-intake-port head are prohibited.

b) Yamaha TT/XT/SR500s are prohibited.

c) Yamaha singles after serial #484 are prohibited.

14.2.6 SPORTSMAN 750: 1974 and earlier machines manufactured as 601-750cc, including like-design models. Eligible machines include:

BSA A65, A70

Harley-Davidson Sportster-based bikes, XR750 (iron-barrel only)

Norton 750

Nourish/Weslake twins

Triumph 650, 750 twins, triples

Yamaha XS650

a) Aftermarket swingarm frames are allowed, including Champion, Cheney, Redline, Rickman and Trackmaster.

b) 1972-up alloy-cylinder H-D XR750s are prohibited.

c) Norton 850s are prohibited.

14.2.7 SEVENTIES SINGLES: Late 1970s era four-stroke single-cylinder motorcycles up to 600cc such as were raced in period dirt track events. Eligible machines include:

1982-83 Honda FT-500 Ascot

1976-78 Honda XL-350 (center port head)

1979-81 Honda XL-500 (all engine numbers with prefix PD01E-), maximum 38mm carburetor

1979-80 Honda XR-500 (engine # PE01E-5000001 up to -5200001), maximum 38mm carburetor

1978-79 Suzuki DR-370 and SP-370

Yamaha TT-500 (engine prefix 583, 1T1 or 240), XT-500 and SR-500

Sportsman 600 vintage four-stroke singles not exceeding 600cc may bump up into this class.

Radial head four-valve Honda XR-500s are prohibited.

Reed valve Honda XR-500s are prohibited.

a) All frames must be dual-shock, including period-style aftermarket items.

b) Shocks with remote reservoirs are not permitted; piggyback-type shocks are allowed.

c) 38mm maximum diameter fork tubes are allowed. No external dampening adjustments are allowed on forks.

d) Up to WM4.5 rims are allowed.

e) Wide Goodyear Eagle DT-II tires are allowed on the rear wheel.

f) Adjustable type fork triple clamps are allowed.

g) A 600cc limit (plus allowable overbore of .080") will be strictly enforced for all Seventies Singles machines.

h) Maximum carburetor size is 44mm. Period flat-slide carburetors are permitted; Lake, Lectron, Posa and Gardner only.

i) Unless otherwise noted, all general vintage class rules apply.

Any requests for new rules or machine eligibility must be submitted to the Dirt Track Rules & Eligibility Committee before coming to the racetrack.

14.2.8 SEVENTIES TWO-STROKE: 1981 and earlier air-cooled two-strokes up to 250cc. Eligible machines include:

Can-Am (all 250s regardless of year of manufacture)

Harley-Davidson MX250

Honda CR

Kawasaki KX, including 1982 model

KTM MX

Suzuki RM

Yamaha YZ

a) All frames must be dual-shock, including period-style aftermarket items.

b) Shocks with remote reservoirs are not permitted; piggyback-type shocks are allowed.

c) 38mm maximum diameter fork tubes are allowed. No external dampening adjustments are allowed on forks.

d) Up to WM4.5 rims are allowed.

e) Period flat-slide carburetors are permitted; Lake, Lectron, Posa and Gardner only.

f) Sportsman 250 two-strokes may bump up to this class.

Additional bikes and rule updates will be included as the class develops.

14.2.9 SENIOR: Riders age 50 or older on any Sportsman-eligible machine.

14.2.10 SUPER SENIOR: Riders age 60 or older on any Sportsman-eligible machine.

14.2.11 NOVICE: A non-championship class for entry-level riders on any Sportsman-eligible machine; displacement breakdowns for 0-250cc, 251-600cc and 601-750cc may be run, but will be combined into one class in instance of a low rider turnout.

14.2.12 SUPPORT CLASSES. Sportsman 125, Seventies Twins (see below) and Veteran (riders age 35 and older on Sportsman machines) may be run as support classes at the promoterís discretion.

a) Seventies Twins: A support class for late-1970s style dirt track racers including Harley-Davidson XR750s and Ducati 860s. Twin-cylinder Sportsman 750 machines are eligible, as are other twins up to 850cc in capacity (except XR750). Harley-Davidson XR750s and Ducati 860s are limited to 750cc.

Chassis: Similar to Seventies Singles; limited to twin-shock, circa 1980 chassis with maximum 38mm forks and WM4.5 rims. Wide dirt track tires may be used.

Carburetor rules are the same as Seventies Singles; no "modern" flat slides or pumper carbs.

14.2.13 EXHIBITION CLASSES. AHRMA dirt track exhibition classes include:

a) Board Track and like-design dirt track machines

b) Two-valve speedway machines (on soft tracks where conditions allow)

14.3 TT CLASSES

14.3.1 DINOSAUR: 1951 and earlier, with no limitations on valve arrangement or displacement.

14.3.2 CLASSIC 250: 1967 and earlier and approved-design machines up to 250cc. (For machine list, see 14.2.2).

14.3.3 CLASSIC OPEN: 1967 and earlier and approved-design machines manufactured as 300cc and larger, with no limitations on valve arrangement. In addition to machines listed in 13.2.3, the following are eligible:

AJS/Matchless Typhoon singles, 600, 650, 750 twins

BSA A10, A65

Harley-Davidson XL, XLR

Norton 600 OHV singles, or 650, 750 twins

Triumph pre-unit or unit 650

14.3.4 SPORTSMAN 250: 1974 and earlier machines up to 250cc (see 14.2.4).

14.3.5 SPORTSMAN 600: 1974 and earlier machines manufactured as 251-600cc (see 14.2.5).

14.3.6 SPORTSMAN 750: 1974 and earlier machines manufactured as 601-750cc (see 14.2.6). Harley-Davidson KH883cc sidevalve is eligible for Sportsman 750 TT only.

14.3.7 SEVENTIES SINGLES: Late 1970s era four-stroke single-cylinder motorcycles up to 600cc such as were raced in period TT events (see 14.2.7).

14.3.8 SEVENTIES TWO-STROKE: 1981 and earlier air-cooled two-strokes up to 250cc.

14.3.9. SENIOR: Riders age 50 and older on any Sportsman or Classic eligible machine.

14.3.10 SUPER SENIOR: Riders age 60 or older on any Sportsman or Classic eligible machine.

14.3.11 NOVICE: A non-championship class for entry-level riders on any Sportsman-eligible machine; displacement breakdowns for 0- 250cc, 251-600cc and 601-750cc may be run, but will be combined into one class in instance of a low rider turnout.

14.3.12 SUPPORT CLASSES. Sportsman 125, Veteran and Seventies Twins may be run as support classes at the promoterís discretion (see 14.2.12).

14.4 RACE PROCEDURES

a) Riders may "bump up" from one period class to another, providing the machine meets all the rules of the newer-period class (e.g., a Classic oval-track machine may run in Sportsman after attaching brakes). Machines may not move up to a larger displacement class.

b) Shifting is allowed during any event in any class.

c) Brakeless and braked machines must never occupy the track at the same time, either in practice or during competition.

14.5 DIRT TRACK TECHNICAL INSPECTION & MODIFICATIONS

a) TIRES: Knobby tires are not permitted. AHRMA encourages the use of 19-inch front wheels and new tires for the safest and most predictable setup. Following is the list of allowable tires. Other tires may be added to the list from time to time by the Dirt Track Rules &Eligibility Committee.

19-inch tires:

Carlisle 51-S 4.00x19
Carlisle Avenger 4.00x19 or smaller
Carlisle Universal 4.00x19 or smaller
Continental Milestone 120/80x19 and 130/80x19
Dunlop K70 4.00x19 or smaller
Dunlop K180F 110/80x19
Goodyear DT1 4.00x19 or smaller
Goodyear Eagle DTII 27.0x7.0x19
Maxxis DTR-1 27.0x7.0x19
Pirelli MT53 4.00x19 or smaller

18-inch tires:

Avon GP1 4.10x18 and Gripster 110/80x18
Carlisle Universal 4.00x18 or smaller
Dunlop K70 4.00x18 or smaller
Dunlop K180 120/90x18
Dunlop Trailmax 120/90x18
Metzeler Enduro 4.00x18 and Enduro 4 110/80x18 &120/80x18
Pirelli MT53 4.00x18 or smaller
Pirelli MT60 110/80x18 and 120/80x18

b) WHEELS: Rim width must not exceed WM3 (2.15") for all classes.

c) BRAKES: Brakes are not permitted in Dinosaur or Classic classes. As an alternative to brake removal, an effective mechanical lockout may be used to disable rear brakes for these classes. Any disc brake caliper with up to two opposed pistons is acceptable for Sportsman. Operating front brakes are not permitted in flat track racing. Hydraulically operated drum brakes are prohibited.

d) CHASSIS: Must be of the same period as the class in which the machine is entered. Dinosaur machines' chassis and engine must be made by the same manufacturer (i.e., OEM chassis or replacement type offered by the engine manufacturer). Frame modifications for Dinosaur class must be of period style. Weld-on rear axle holders are permitted but bolt-on adjustable-height rear axle supports (i.e., Sonicweld type) are not.

Swingarm frames are allowed in Classic classes only if they are production components for that make and year motorcycle and equipped with stock-configuration swingarms. Any aftermarket racing frame must be of rigid type (hardtail or strutted) to compete in Classic classes. Post-1967 Champion, Redline, Trackmaster, Ossa DMR, Bultaco Astro and similar type dirt track frames are not allowed in Classic classes even if fitted with struts. Aftermarket frames cannot be used in the Classic Open TT class.

Sportsman class machines may use a production chassis from 1974 or earlier, or an aftermarket chassis of the type and configuration used in North American dirt track competition prior to 1975. Typical eligible models include Champion, Trackmaster and Redline. Others must be submitted to the Dirt Track Rules & Eligibility Committee for an eligibility decision. Requests must be accompanied by documentation and photographs establishing the configuration and appropriate time-line. Accurate replicas of eligible dirt track aftermarket chassis are eligible as long as they conform to the original design and other class rules. See roadrace rule 9.7.3f for a diagram of a braced swingarm eligible for Sportsman and Seventies Singles machines only.

No machine in any category may have more than 7 inches of front wheel travel and 4 inches of rear wheel travel, measured at the axle, regardless of original specification.

e) All of the following must be covered with rubber and conform with AMA and AHRMA competition rules: footpegs, stand mounting lugs, brake rods and anything else that might present a hazard.

f) Footpegs must be of the folding type able to pivot upwards and aft at a 45-degree angle.

g) FORKS: Machines must use OEM or pre-1975 aftermarket forks, with maximum 35mm diameter tubes. Ceriani, Red Wing, Betor or other non-period telescopic forks are not allowed on Dinosaur class machines. No adjustable front fork triple clamps are allowed in any class except for OEM adjustable steering stems on Can-Am and certain period C&J frames. Non-adjustable, billet style triple clamps are allowed.

h) SHOCKS: No single-shock chassis are permitted. Dual-shock machines may use any shock absorber, providing the technology and design was commercially available in 1974 or was supplied as OEM on any AHRMA-legal dirt track machine.

i) ENGINE: No major engine components may be changed or updated to later model parts (i.e., cylinder, head, cases, etc.). Hydraulically operated clutches are prohibited.

Machines in all classes may be built to the class limit, plus overbores (in TT racing only, Dinosaur and Classic Open must use the stock displacement, plus overbores). Overbore limits for all classes are as follows: +.080" for singles; +.060" twins; +.040" triples; +.020" fours. Pre-unit Triumph 500 twins may use 650cc crankshaft but must not exceed +.020" overbore. Any AHRMA official may ask for a random engine teardown at any event, without posting the protest fee. Any rider refusing to teardown or found to be using an oversize engine in any AHRMA competitive event is subject to an immediate 13-month suspension of his/her racing license.

Two-strokes are limited to no more than two cylinders; multi-cylinder four-strokes are permitted. Use of compression releases is allowed on any two-stroke machine. All two-strokes must be equipped with an effective silencer. Throttles must be self-closing. All motorcycles must be equipped with a functional handlebar-mounted kill switch. If the motorcycle is equipped with a magneto where an operational kill switch cannot be fitted, then the carburetor settings must be such that a running engine shuts off when the throttle is fully closed.

j) CARBURETORS: No flat-slide or injection-type carburetors are allowed. "Power jet" and "Pumper" type (accelerator pump-equipped) carburetors are not permitted unless such mechanisms are disconnected or removed. Fuel injection is not permitted. Smoothbores with concentric float bowls are not permitted. Period carburetors are encouraged.

Classic 250 two-strokes are restricted to 32mm for singles, 28mm for twins except that Ossas may run OEM 33mm IRZ carburetors.

All Dinosaur bikes must use OEM or period-type carburetors with specific exceptions as identified in 10.4.1c of the Class C roadracing rules.

k) All drain plugs must be safety wired.

l) All modifications must be consistent with the spirit of the class; period modifications only.

m) Appearance and workmanship of a reasonable standard shall be enforced.

n) All machines must carry three 10x12" (minimum) rectangular number platesóone on the front, and one clearly visible on each side of the motorcycle. Novice entrants shall have yellow plates, all others must be white. All numbers must be black, at least 8" tall, with a minimum 1" brush stroke. Any letters must be at least 3" tall. It is the rider's responsibility to be scored; legible numbers on the rider's back and helmet are highly encouraged. All competitors must display their AHRMA-assigned number unless granted prior permission to run a different number at that event only.

o) In addition to the rules in Section 14, riders must comply with all applicable rules in Sections 3 (events and race procedure), 4 (entry procedure) and 6 (offenses, penalties, protests and appeals), rule 9.7.11 (fuel) and rule 9.7.17 (AHRMA decals; two required and may be placed on any readily visible part of the motorcycle).

14.6 TT TECHNICAL INSPECTION & MODIFICATIONS

a) Dirt track rules 14.5a, b and d through o apply.

b) BRAKES: All TT machines must have a functional rear brake; front brakes are optional but highly recommended. Dinosaur bikes must use OEM drum brakes or single-leading-shoe/single-trailing-shoe type with a maximum brake diameter of 8.75 inches and a maximum shoe width of 1.75 inches. Classic and Sportsman machines may use pre-1975 drum or period disc brakes with calipers utilizing up to two opposed pistons. Hydraulically operated drum brakes are prohibited.

c) SUSPENSION: Maximum suspension travel for machines in all classes, including Seventies Singles, is 7 inches in the front and 4 inches rear, measured at the axle.

14.7 SERIES POINTS AWARDS

a) A rider will receive points if he or she is the sole class competitor.

b) A rider must score points in at least two events to be eligible for series awards, or according to requirements as published in Vintage Views from time to time. National series awards are based on a riderís 10 best finishes.

c) If there is less than a full field for the final, a rider who failed to start his heat race may run in the final but will start from the penalty line.

d) Riders who start a main event will be scored in the order they cross the finish line at the pre-determined number of laps. Any rider not completing the entire distance will be scored according to the number of laps completed. There are no "DNFs."

e) The following series points are awarded.

  • Position Points   Position Points
    1 20   8 7
    2 16   9 6
    3 13   10 5
    4 11   11 4
    5 10   12 3
    6 9   13 2
    7 8   14 1
         

    15-on

    0

  • f) Points will be paid only to entrants who start the main event. In the case that fewer than 14 riders compete in a main event, points through 14th position will be paid. This will be determined by the finishing order in a "B" main, or in qualifying semis or heats, whichever is appropriate. A rider must complete at least one lap to earn points.

    g) Year-end scoring ties will be broken by the greatest number of first-place finishes, then second-place finishes, third-place, etc. In the event of an absolute tie, the oldest rider wins.

    h) TT National races award Dirt Track series points for their respective classes.


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