Learn The Chopper Basics Before You Build One

            Chopper Basics: A Simple Look At How Choppers Work...
           
             If you want to learn how to build a chopper from start to finish and
            study all the fine detials involved in every step of the process,
            this article is not for you. It's simply too large a subject to
            discuss in one simple article. But if you want to learn the basics
            of how a chopper is built, and how each of the parts work, you may
            find this article extremely informative. This article is probably
            best for the novice chopper enthusiast who wants to take the fist
            step in learning how to build a chopper.
            If you want to ad in any additional information, please contact us
            and we may include it in this article. We would love to expand on
            this and make an advanced presnentation. And with your help on how
            to build a chopper we can accomplish this together.
            Also, if after you have read this article you want more detailed
            information I recommend this video (DVD) series.
            Following is the brief description about the parts used in chopper
            motorcycles and a basic guide to what's needed in the process of
            learning how to build a chopper...


            Chopper Basics: The FRAME

            The most important step in learning how to build a chopper is
            understanding the frame. The frame is one of the most important
            components on a motorcycle, especially on a large motorcycle. The
            frame must be designed strong enough and built rigid enough to:

              Manage the power and torque created by your power train and
              maintain its alignment during the full range of
              acceleration/deceleration.

              Maintain wheel alignment during extreme braking and hard
              cornering, as well as while riding over rough surfaces.

              Provide a solid mounting surface and pivot points for the front
              and rear suspension.

              Effectively support the weight of the motorcycle itself as well as
              the rider, a passenger, and travel gear.

            Frame Construction

            The frame is made from high-strength seamless steel tubing and
            utilizes a high tensile strength welding process to extremely tight
            tolerances.
            Chopper Basics: Types of Frames:
            1) Hidden Shock Frame
             A) Steering Head
             B) Frame
             C) Rear Forks and Pivot Shafts
             D) Shock Absorbers

            2) Rubber Mount Frame
             A) Steering Head
             B) Frame
             C) Rear Forks and Pivot Shafts
             D) Shock Absorbers

            3) Rigid Frame
             A) Steering Head
             B) Frame
           
            SYSTEMChopper Basics: The SUSPENSION  (Front & Rear)

            In learning how to build a chopper beyond frame design, the
            suspension system is the chief ingredient in determining the
            handling capability of a motorcycle. The suspension system is
            responsible for keeping the wheels on the ground and absorbing the
            shock as the motorcycle passes over uneven surfaces in the road.
            Both the front suspension (telescoping front forks) and the rear
            suspension (rear swing arm and shock absorbers) operate by
            compressing and extending as the motorcycle passes over a bump,
            absorbing the shock of the bump to keep the motorcycle stable. The
            front and rear suspension utilize springs for the up and down
            compression and extension, and suspension dampers to stabilize the
            up and down movement. Without the suspension dampers, the springs in
            the suspension system would continue to bounce up and down after
            each bump creating a “rocking horse” effect.

            FRONT SUSPENSION

            Motorcycles use two types of telescopic front fork assemblies:
            conventional and inverted. Each assembly consists of two fork tubes
            which contain springs, spring dampers and oil. The fork legs slide
            on the fork tubes. The tube or leg extends and compresses within
            itself as a shock absorber. The two types differ in these ways. On
            the conventional type, the fork tubes are captured by the triple
            clamp positioning the fork leg at the bottom of the assembly. The
            inverted type was developed on racing motorcycles to place the
            heaviest and strongest part, the fork leg itself, in the triple
            clamp - thus inverting the assembly. This design gives more rigidity
            to the fork, reducing fork tube flex and lessens the unsprung
            weight, improving suspension response. The triple clamps (trees) and
            fork stem hold the front fork tubes to the frame and keep the tubes
            aligned. The fork stem is an integral part of the triple tree and
            fits through the steering head allowing the forks to be turned to
            the right and left.
                                                                       
            Inverted Fork Suspension                                     
            Conventional Fork Suspension
            A) Triple Clamps and Fork Stem
            B) Fork Legs                                                                                                              
            C) Fork Tubes

            REAR SUSPENSION 

            There are two types of rear suspension exposed shock absorbers and
            hidden shock absorbers. The rear fork is attached to the frame with
            the pivot shaft. The arms of the rear fork (often called the swing
            arm) hold the rear wheel and keep it aligned. The rear shock
            absorbers mount to the rear forks and the back struts of the
            motorcycle. The ability of motorcycle to handle effectively while
            cornering, breaking, etc. depends in part on the suspension system
            having the right amount of “controlled flexibility.” Over time or
            under certain conditions if your suspension seems too rigid or too
            spongy, it may need servicing or adjustment.

            Chopper Basics: The POWERTRAIN
            The power train is composed of:
            A. V-Twin, 107 cubic-inch, or any four stroke engine
            B. Chain driven primary drive except in metric applications
            C. 5-Speed transmission or 6-Speed transmission
            D. Belt driven final drive down Chain works just as well

            Chopper Basics: How the Engine Works

            In learning how to build a chopper, you have to have a thorough
            understanding of the engine. A four-stroke engine means that each
            piston moves four times (strokes) for the engine to complete one
            full cycle.
           
            Four Strokes of engine are: Suck, Squeeze, Bang, Blow!!!

            (Suck)Intake Stroke -The piston moves down while the intake valve is open,
            pulling the air/fuel mixture into the cylinder.
            (Squeeze)Compression Stroke - The piston moves upward pressurizing the
            air/fuel mixture.
            (Bang)Power Stroke - As the spark plug ignites the compressed air/fuel
            mixture, the combustion pushes the piston back down.
            (Blow)Exhaust Stroke - With the exhaust valve open the piston moves upward
            again, pushing the burned gases out of the cylinder.

            The valves opening & closing, the pistons cycling at 3,000 to 5,000
            revolutions per minute (at normal operating speeds), the spark plugs
            firing all occurring in the proper timing is what it takes to keep
            your motorcycle down the road.

            PRIMARY DRIVE:

            The purpose of the primary drive is to deliver power from the engine
            to the gear box. The primary, or initial drive, on your motorcycle
            is composed of a primary drive chain which runs from the crankshaft
            in the engine to the clutch in the gear box. The power from the
            engine to the gear box is engaged and disengaged by the clutch.
           
            TRANSMISSION (GEAR BOX):

            The transmission or gear box connects the primary drive to the final
            drive with a set of shafts and different size gears. Engaging the
            different size gears in the gear box allows for a wide variety of
            rear wheel speeds, while allowing the engine to operate
            "comfortably" within its range of normal operating speeds. Smaller
            gears provide more torque while larger gears provide more speed.
            This pairing of different size gears is called “gear ratio” or “gear
            reduction”. The gear ratio or reduction in your Big Dog power train
            begins with the primary drive, increases in the gear box and
            culminates with the final drive.

            FINAL DRIVE:

            The final drive, is the last link in the power train and connects
            the gear box to the rear wheel.

            Chopper Basics: The BRAKING SYSTEM

            The front brake is a hydraulic disc type, which is operated by the
            hand lever on the right handle bar. It is composed of:
            A. Front disc rotor
            B. 4-piston caliper
            C. Braided stainless steel lines
            D. 5/8" bore master cylinder and fluid reservoir
            The rear brake is a hydraulic disc type which is operated by the
            pedal on the right foot rest. It is composed of:
            E. Rear disc rotor
            F. 4 piston caliper
            G. Braided stainless steel lines
            H. 5/8" bore master cylinder and fluid reservoir
            How the Braking System Works
            The braking system is designed so that the front brake should supply
            75% of the braking power or your motorcycle. It should be used as
            the primary brake while using the rear brake as secondary.
            FOR NORMAL BRAKING: Apply both the rear and front brakes while down
            shifting to match your road speed.
            FOR MAXIMUM BRAKING: Close the throttle and firmly apply both rear
            and front brakes; then pull in the clutch lever before coming to a
            complete stop to prevent the engine from stalling.

            Chopper Basics: The CLUTCH SYSTEM

            A. Clutch hand lever
            B. Clutch cable
            C. Clutch assembly
            The clutch assembly is positioned between the primary drive chain
            and the gearbox, and provides a way to connect and disconnect the
            primary drive (power transmitted from the engine) and the gearbox.
            The clutch assembly is disengaged by pulling the clutch hand lever
            in against the handlebar grip; it is engaged by releasing the lever.
            When the engine is running, the primary drive is spinning. As the
            clutch is engaged (the hand lever released) the power from the
            engine is transferred to the gearbox and the rear wheel. When the
            clutch is disengaged (the hand lever pulled closed) the gearbox does
            not receive power from the engine.

            THE CLUTCH ASSEMBLY:

            Simply put, the clutch assembly is composed of round discs called
            “clutch plates” which are contained inside a clutch housing (often
            called the clutch basket). These plates are pushed together by
            spring tension. When pushed together, friction between the plates
            causes them to bind or couple together which provides the link to
            transfer power from the engine, through the clutch, to the gearbox.
            CLUTCH HAND LEVER & CABLE:

            When the clutch hand lever is pulled, the clutch cable acts against
            (or relieves) the spring tension within the clutch assembly to
            release the friction grip inside the clutch. As the clutch plates
            separate from each other and slip, this de-couples the gearbox from
            the engine. The clutch assembly is a mechanical wet clutch.
            Mechanical means that it does not operate by hydraulic pressure. A
            wet clutch means that the clutch assembly operates immersed in an
            oil bath. This not only helps to keep the clutch assembly cool, but
            also washes away loosened friction material from the clutch plates,
            keeping the surfaces clean and free of debris.

            Chopper Basics: The ELECTRICAL SYSTEM

            The electrical system provides power for your motorcycle. It is
            powered by a high cranking, long -life, 12-volt battery. The
            electrical system can be divided into five sub systems:
            1. STARTING SYSTEM
            A. Battery
            B. Start switch - Not Shown
            C. Solenoid (Relay)
            D. Starting motor (Starter)
            2. CHARGING SYSTEM
            E. Alternator
            F. Voltage regulator
            A. Battery
            3. IGNITION SYSTEM
            G. Ignition switch and ignition coil
            H. Kill switch - Not Shown
            I. Electronic Control Unit
            J. Spark plugs - Not Shown
            4. ACCESSORY SYSTEM
            * Lights
            * Horn
            * Turn Signals
            * Warning Lights
            * Other Accessories
            5. CIRCUIT BREAKER

            Chopper Basics: The FUEL SYSTEM
            A. Fuel tank
            B. Fuel supply valve
            C. Carburetor and air filter
            D. Throttle grip & cable
            E. Fuel lines
            The fuel system on your motorcycle is a gravity flow system, so no
            fuel pump is required. Although it is a simple system, it must
            perform the complicated task of blending (or mixing) the fuel and
            air together in the right proportions and supply this mixture to the
            engine.
            FUEL SUPPLY VALVE:
            The fuel supply valve (petcock) is a manually operated on/off valve
            designed to control the fuel flow from the gas tank to the
            carburetor.
            CARBURETOR:
            The carburetor is the central part as well as the most complex part
            of the fuel system. Its primary job is it to atomize (break up) the
            fuel into small droplets, and mix the atomized fuel with the right
            amount of air. This mixing (or metering) of fuel and air is called
            the air/fuel ratio. It is precisely here (the carburetor’s ability to
            atomize and properly meter the air-fuel ratio) that performance, as
            well as fuel efficiency, is won or lost.
            CARBURETOR OPERATION:
            In basic terms (see illustration) as air enters the carburetor, its
            speed increases passing through the bottleneck in the throat of the
            carburetor. This increase in air speed creates a vacuum within the
            carburetor which pulls fuel from the fuel reservoir into the air
            stream. The fuel is atomized and mixed as it enters the air stream
            and is then provided to the engine.
            THROTTLE GRIP AND CABLE:
            The throttle grip and cable are connected to the throttle plate or
            throttle slide inside the carburetor (see illustration). The
            throttle plate and/or throttle slide controls the flow of air
            through the carburetor. Opening the throttle allows more air to pass
            through the carburetor which draws more fuel into the air stream.
            This results in increased power from the engine.
            AIR FILTER:
            The air filter keeps airborne dirt and debris from entering the
            throat of the carburetor and passing into the engine.

            Chopper Basics: CONTROLS AND DISPLAYS

            TURN SIGNAL SWITCHES:
            Located at the base of each handlebar control group. The right
            handlebar turn signal switch operates the right front and right rear
            flashing lamps, and the left handlebar turn signal switch operates
            the left. To operate the turn signal you must depress and release
            the turn switch.

            Chopper Basics: MIRRORS AKA Pig Spotters!

            Generally your Motorcycle is equipped with two mirrors. Adjust the
            mirrors to clearly reflect the area behind the motorcycle.
            A. SPEEDOMETER/ODOMETER:
            The speedometer registers miles per hour of forward speed. The
            odometer registers the number of miles the vehicle has traveled.
            B. TURN INDICATOR LIGHTS:
            The green TURN indicators will flash when turn signals are
            activated.
            C. HIGH BEAM LIGHT:
            The blue BEAM indicator light, when lit, signals that the headlamp
            high beam is on.
            D. TRANSMISSION NEUTRAL LIGHT:
            The green NEUTRAL light turns on to indicate when the transmission
            is in neutral.
            E. OIL INDICATOR LIGHT:
            The red OIL indicator light, when lit, signals that oil is not
            circulating through the engine. The light will come on when the
            ignition is turned on prior to starting the engine. With the engine
            running, this light should be off except possibly at low idle. If
            the oil pressure indicator light does not go off at speeds above
            idling, it is usually because of an empty oil tank or diluted oil.
            In freezing weather the oil feed may clog with ice and sludge,
            preventing oil circulation.

            GEAR SHIFTER: The gear shifter is located on the left side, and is
            operated with the toe of the left foot. There are five or six
            forward gears (depending on model) and no reverse. Pushing the lever
            all the way down (one full stroke) shifts the transmission to the
            next lower gear, while lifting the lever all the way up (one full
            stroke) shifts the transmission into the next higher gear. The
            operator must release the gear shift lever after each gear change to
            allow the lever to return to its central position before another
            gear change can be made. The neutral position is between first (low)
            and second gears. First gear is the last gear position that can be
            found by pushing the lever full strokes downward. To shift from
            first gear to neutral, lift the lever half its full stroke.
            SIDE STAND:
            The side stand is located on the left side of the motorcycle and
            swings outward to support the motorcycle for parking.
            BRAKE PEDAL:
            In this article on how to build a chopper, we are going to end it
            with the brake pedal. The Brake pedal controls the rear wheel brake
            and is located on the motorcycle's right side. It is operated by the
            right foot.
            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          

Now I know a lot of this applies to Harley Choppers, but it is all useful info to any gearhead out there. Make what works for work for you. Hope y'all enjoyed!!!