Reserved for V-Twin cylinder configuration motorcycles powered by S&S 124 c.i. Super Sidewinder Plus Evo style or Twin Cam engine competing heads up on a .400 pro tree. Motorcycle must be ridden under its own power to staging, starting line and back to the pit area after completion of run - no towing or pushing allowed (except for verified breakage after the conclusion of a run). Minimum weight at conclusion of run, including rider, must be 750 lbs.
- ENGINE
Engine: Must be S&S 124 cubic inch Evo style, or twin cam style, or TC with V2 mounts, and must use all S&S "124" components. S&S logos must be clearly visible. S&S pistons are supplied with a dry film lube from the factory. No additional internal engine coating is permitted (i.e., friction reduction or thermal barrier treatments). Crankcase and all tanks containing fluids must have vent tubes routed to a catch can or have a non-spill breather system on the motorcycle.
Configuration: 4-1/8 bore x 4-5/8-inch stroke. Maximum overbore .030. Connecting rod length 7.668.
Induction: Naturally aspirated S&S VFI with supplied module or one S&S carburetor or S&S G-Extreme Dual Carburetor System. VFI must use a radiused inlet, air cleaner assembly, or tuned runners. Carburetor(s) may be modified and air filter, velocity stack, or radiused inlet is required.
Cylinder Heads: Must use either S&S SSW or B2 style heads. Porting is allowed, but the original factory port opening size, shape, and location must be maintained. Oversize valves are not allowed. No titanium valves are allowed. Valve sizes are to be as follows. For the SSW head: 2.00-inch int. and 1.605-inch exh. For the B-2 head: 2.220-inch int. and 1.800 exh. Stock 124 rocker arm or S&S part number 90-4098 (1.725:1) rocker arm only.
Pistons: Any S&S 4-1/8" bore (up to +.030 oversize) piston may be used. Piston crown and valve pockets may be machined for clearance. Gas porting of the top ring is allowed. No welding or other piston modifications are allowed.
Camshaft: S&S .640 or .675 lift grind only.
Fuel: AHDRA specified fuel only. No Fuel additives and /or combustible oil additives are allowed. Dielectric constant, as per AHDRA testing meter, must match baseline reading of specified fuel. Fuel must match color of specified fuel. Fuel must match AHDRA generated graphs in random Gas Chromatography analysis of specified fuel.
- DRIVE TRAIN
Chain Guard: Chain or belt primary and chain or belt secondary must have guards.
Transmission: Any type of five or six-speed foot shift only transmission is allowed. No automatic transmissions. Clutch must be hand operated. No clutch assists or lockup clutches are allowed. No ignition electric kill or interrupt, or air shifters or electronic solenoid shifters are allowed to aid shifting. Internal modifications are limited to back-cut, clearance, and lightening operations.
- SUSPENSION AND BRAKES
Brakes: Front and rear mandatory (disc or drum).
Controls: Handle bar controls must be located in safe, workable position. Foot pegs and foot controls shall be located ahead of swing arm pivot. Snap-back throttle return is mandatory.
Suspension: Must have a working front and rear suspension. Rigid frames are not allowed. Front suspension minimum size is 32 mm with a minimum of 2-inch travel. Rear suspension must have shocks, not struts. Rear suspension must have a minimum of 1-inch travel.
- FRAME
Frame: Must be commercially available with at least 25 units being produced per year. Frame modifications are not allowed with the exception of AHDRA approved notching of the backbone to clear cylinder head.
Ground Clearance: 2-inch minimum with rider on bike (including exhaust and kickstand) and rear tire pressure of 10 PSI.
Wheel Base: 68 inches maximum.
Wheelie Bars: Wheelie bars are not allowed.
- WHEELS AND TIRES
Tires: Tires must be V-rated, D.O.T. approved, commercially available motorcycle tires. No car tires are allowed. Must have 2/32 tread on front and rear. Any size.
Wheels: Stock O.E.M. wheels or aftermarket performance wheels of any size.
- BODY
Body: Any type allowed.
Fairing: Allowed.
Seat: Stock O.E.M. or seat with a step up. All seats must be upholstered.
- ELECTRICAL
Ignition: Any type is allowed. Delay boxes, two steps, or electronic throttle stops are not allowed.
Charging System: Must be present and working O.E.M. type (no lightening of magnet rotor).
Starting System: Must be electric on board. External jump-starts, push starts, rollers, or external starters are not allowed.
Control Switches: Must be mounted and constructed in a safe, craftsman-like manner. Must have emergency kill switch with tether to rider.
Computers: No data gathering computers are allowed. Shift light is allowed.
Lights: Must have D.O.T. approved headlight, taillight, and brake light present and properly functioning.
- RIDER
Credentials: Valid AHDRA 9.90 competitor license.
Helmet: Full-coverage (Snell-2000 or better) approved helmets only. Eye protection required.
Protective Clothing: Leather jacket, full-finger gloves, and high-top leather shoes or boots are mandatory. Riders exceeding 120 mph must wear full leathers. AHDRA highly recommends reinforcement and/or armor in the knee, elbow, shoulder and knuckle areas. Lightweight leather athletic or driving shoes are NOT recommended. Back/spine protectors are mandatory.
- TECH
Tech: All motorcycles must be tech approved prior to any runs. Motorcycle, rider, and protective gear must be present at the tech area. The tech official will have final authority on any unclear rules or equipment. Winner and runner-up will be subject to teardown after final round.
