First things first: Consider your comfort riding for the long stretches of road on this tour? If you're backside and wrists are aching halfway through the first day, you're going to have a serious problem to contend with. Are you riding with a passenger? Consider your seat and theirs as well. After a few hours in the saddle are you comfortable? If your passenger is shifting their weight to get comfortable or wanting to get off the motorcycle more frequently because they are sore it will become and issue. Harley Davidson aftermarket seats from LePera and Mustang are available that offer exceptional comfort and design. Two choices to consider are the new Le Pera Maverick seat or the Mustang Vintage seat. Think about your handlebar grips. Are your hands comfortable? The Performance Machine Contour Grips have been a long time and are a perennial favorite.

Once you're confident you'll be comfortable on the bike, the next thing to consider is load distribution. The weight of fully loaded luggage and saddlebags can add up and change the way the motorcycle handles. Generally speaking, a backpack is a terrible idea. Not only will it wear you out quicker but it can also prevent air circulation along your back and just be plain uncomfortable after a while. Riding long distances can take enough out of you, you need to stay as comfortable as possible. There are a lot of alternative motorcycle luggage systems. The Nelson Rigg Riggpak Deluxe Tourer CTB-900 and CTB-950 offer approximately 1.6 cubic feet of storage. For those of you with a trunk the T-Bags Bookcase is a good add on to increase storage capacity. Pack heavy items and less frequently used items at the bottom of the motorcycle luggage. Another frequently overlooked consideration is having items such as maps, snacks, and water easily accessible. For these items a tank bag is recommended. Consider a tank bag with straps that can be easily removed for carrying.

Inspect your tires. How miles have you ridden on this set of tire? Tire pressure should be checked regularly as part of your normal routine. It's not unheard of to buy new tires for a big trip, especially if the ones currently on your bike are noticeably worn. The thicker tread of a new tire won't just make the ride a bit smoother, it also offers additional protection against blowouts. The Metzeler ME880 Marathon is an excellent tire to consider. Don't think you have to throw away your partially worn tires, just take them off for the trip. You can use them again when you get back.

The next thing to consider is your bike's suspension. Shocks and front end suspension springs wear out and need to be inspected. If the front suspension springs are worn and tired the steering will be heavy, the front end will bounce, and you will not have a smooth rebound from the bumps in the road. Similarly if the rear shocks are worn you will notice bouncing and uneven rebound. Aside from the comfort of better performing shocks there is the impact worn shocks and front end springs have on handling. Either set it up yourself or have a qualified mechanic make the adjustments or do the install of new shocks. Progresive Suspension has a complete line of suspension products for Harley Davidson motorcycles. Whatever you do, DON'T tune or add components to your bike just prior to a long trip. Give yourself a couple of hundred miles to make sure any potential problems have had time to make themselves known and get sorted out. If you plan to do it yourself, check out the article we have on Tuning Your Bike's Suspension.

For the remaining areas we will use a quick checklist:

Controls: Check your clutch cable. Is it sloppy or have slack. Check the brake lines and master cylinder. Are the brakes solid and responsive or mushy.

Fluids: Check your Engine oil, Transmission oil, and Primary oil.

Lights: Headlights, High beams, tail lights, brake lights, turn signals all working.

Battery: Inspect your battery and make sure it is in good working order.

Finally, having some mechanical and/or electrical skills as well as a good feel for your bike's normal workings can be valuable. It's a great idea to check all the nuts and bolts on your bike to make sure everything is correctly tightened. Keep in mind that there IS such a thing as over-tightened and you want to avoid doing it. Pay attention to the sounds your bike makes when you first start it up and during normal riding. Even if you don't know what's wrong, being able to identify that something sounds a bit off today from the way it sounded last week is the first step in getting a problem fixed before it goes critical and leaves you stranded in the middle of nowhere.

The Shovelhead engine got its name from the distinctive look of the engine's rocker box covers.   These covers resemble the heads of coal shovels, which is how the Shovelhead got its name.   The Panhead engine was originally developed with hydraulic valve lifters and later a hand-clutch/foot-shift option.   The biggest advancement came in 1965 on the Electra Glide with the the electric starter.   As time went on, the Panhead lost its appeal and went out of style as Harley Davidson developed bikes that required more horsepower.

The Shovelhead engines of the sixties entered the scene with newly designed top ends that were invented to give you more acceleration and power.   However, motorcycle experts that deal in antique Harley parts say that the weight of the new shovel head engine detracted from the speed and power of certain models in the sixties.

The weight of the Shovelhead engine combined with its proximity to the ground affected the steering of the bike.   As the Harley Davidsons approached top speed, the shovelhead engine impacting the maneuverability resulting in by some riders accounts a tendency to weave.  

Minor changes that were made to the Shovelhead engines in the 1970’s helped fix some of the problems demonstrated by the much heavier sixties shovel head model.   Those who have been following the history of Harley Davidson products say that even these revisions did not quite catch the Shovelhead"up to speed."   As Harley Davidson was trying to revise the model during the great energy crisis in the 1970s, they had to stick by government regulations that basically said motorcycles could not have more than a top speed of 90 miles per hour.

If the engine came with a feature called the FLH Electra-Glide Package, it was identified as a shovel head engine for police bikes.   This feature was also sometimes called the Police Option as it made it easier for them to run cars off the road.   This was a skill that was often also emulated by pranksters who road Harely Davidsons at the time.

The FLH Electra-Glide package also enabled the engine to turn over longer while the machine was in idle.   However this feature also made for a heavy bike that was not easy for the average rider to maneuver or brake instantly.

Finding a Harley Davison Shovelhead engine with the original FLH Electra-Glide package is very rare.    Motorcycle antique dealers and Harley Davidson parts collectors to this day seek out original Harley Davidson motorcycles with the Shovelhead engine.

The pan-head engine is Harley-Davidson's second overhead-valve engine.   The PANHEAD got its name from the large flat covers at the top of the cylinder heads.  It had a better cooling system than the Knucklehead, as well as other harley modifications that reduced wear.  This made it easier to maintain.  It was quieter and cleaner than the Knucklehead which had been used since 1936.

The Harley Davidson PANHEAD didn't change much from the knuckle.   But it came equipped with aluminum heads for more power because the bikeswere getting heavier.   Also, the heat beater was depressed.   In 1955 Harley modified the pan head engine by installing a more efficient lower end (this is why the PANHEAD is quieter than the knucklehead.  Pan head engines were also the first v-twin to come with an electric starting system in 1965.

There are several differences between the pan and knucklehead frames, but most of them are pretty hard to spot.   Some differences are infrequent, like the straight front down-tubes.   The knucklehead frames have straight tubes while most of the rigid pan head frames have "bowleg" tubes.

However, the early 1948, late 56, and 57 PANHEAD frames were also straight bars.   The one sure way to tell the difference is the top motor mount.   The top motor mount on a knucklehead frame is a straight-sided rectangle tab, but the top mount on a PANHEAD is a triangular sort of shape.   It's possible to fit a PANHEAD engine into a knucklehead frame, but it takes some serious grinding and welding, and some hammering.

Harley Davidson Knucklehead engines are distinguished in appearance from the rest of the engines by the head.   The Knucklehead was named after the knuckle-like valve covers look of an upside down cake pan on the top of the engine.   The chrome head of a knuckle head engine resembles the back of your hand.   The sculptural appearance of this engine has great appeal for those who love the look of power.

The Knucklehead engine was the first overhead valve engine made by Harley Davidson.   The Knucklehead was the heart of a boldly redesigned and reengineered cycle, the revolutionary Model E.   Harley Davidson's Knucklehead provided vastly increased horsepower and durability over previous designs. This engine is referred to the "61 OHV" in factory literature of the day and called the Sixty-one in every day circles.

The Flathead was similar in valve operation to the venerable flathead engines that powered now-vintage American automobiles.   Harley's Flathead, with its constant-loss oiling system, remained in production until the mid-'70s, when it was used to power the familiar three-wheeled police trikes.

SEND2PRESS NEWSWIRE
Published: August 8, 2007

SANTA ANA, Calif. -- August 8, 2007 (SEND2PRESS NEWSWIRE) --

Axiom Cycles, Inc. has tackled the wobble and rear-steer problems with Harley Davidson rubber mounted motorcycles adding stabilizer brackets from Ride-Str8 and True-Track to the Harley Davidson parts catalog.  Adding Ride-Str8 and True-Track stabilizer brackets to their selection of aftermarket Harley Davidson parts Axiom Cycles hopes to increase rider safety by improving suspension related issues.

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Harley Davidson Stabilization Products

"After speaking with hundreds of customers in addition to my own riding experience," Mark Nemets, Axiom's president, explained.  "I became increasingly concerned that riders were at risk of crashing as a result of the alleged flaw in the design of the Harley Davidson rubber mounted touring and cruising motorcycles."

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Axiom Cycles researched the cause of swingarm movement that results in wobble and rear-steer and found stabilizer brackets from Ride-Str8 and True-Track.  The problem is the result of swingarm mounts anchored using rubber bushings on each side.  As the rubber bushings compress the rear of the bike tracks in a different direction to the front of the bike which creates a sudden mis-alignment between the front and back tires.  This results in the front trying to compensate or counter-steer.  The flex is most noticeable in a sweeping turn and amplified on rough un-even road surface.

The staff has identified possible solutions and experimented with products on the market that claim to solve the problem with Harley Davidson swingarm flex and wobble.  Through testing on various bikes Axiom Cycles now offers multiple potential solutions from Ride-Str8 and True-Track increasing rider safety on Harley Davidson Touring and Cruising models By attaching stabilizer brackets from Ride-Str8 and True-Track the flex is minimized.

For more information, visit: Axiom Cycles

For more information, contact:
Mark Nemets, of Axiom Cycles, 714-648-0900.  

SEND2PRESS NEWSWIRE
Published: July 25, 2007

SANTA ANA, Calif. -- July 25, 2007 (SEND2PRESS NEWSWIRE) --

Axiom Cycles, Inc. sells aftermarket Harley Davidson parts, custom motorcycle parts and Harley Davidson accessories.  They recently announced new service offerings to include: additional performance tuning, engine rebuilding, and enhanced customer service and technical support.

Axiom Cycles prides itself on providing stellar customer service to bike enthusiasts seeking the finest aftermarket Harley Davidson parts and custom motorcycle parts and Harley Davidson accessories from top-quality manufacturers.  Service and attention to detail are the company's main focus.

"It's important to meet our customers' needs," Mark Nemets, Axiom's president, explained.  "If a customer can't find Harley Davidson accessories or parts when visiting our store or web site, all they need to do is ask; if it exists, our staff will find it."

Axiom Cycles is not a big corporate entity, but a service-driven company that provides personal attention and problem-solving skills.  They offer pre-sale and post-sale assistance to customers.

"Up until recently," Nemets said, "we offered assistance to our Internet customers over the phone and via e-mail for services such as Harley Davidson Performance Tuning.  We have now enhanced our customer service program so customers can submit questions via our web site as well as on location in our Santa Ana, CA store.  This sets us apart from other Internet-based companies, offering similar Harley Davidson Performance Tuning products.  We have full-time mechanics that help solve problems and provide Harley Davidson Performance Tuning technical support in addition to all service related questions for Harley Davidson parts."

Axiom Cycles also provides customers with in house Harley Davidson performance tuning and engine rebuilding services.  For the last 12 months, they have been focusing on enhancing the performance of Harley Davidson motorcycles and now offer an expanded assortment of performance-related parts and services.

Using products from companies like Daytona Twin Tec, Zipper's, and Speed's Performance Plus, Axiom Cycles has produced up to an additional 18 horsepower.

Axiom Cycles also carries parts for custom choppers as well as Bobber Motorcycles from every market manufacturer.  The majority of companies Axiom works with are U.S.-based; imports are limited and only used when required.

The company offers the selection of the largest retailers, and prices below the competition; they provide personal attention that only a full-service shop can offer when selecting Harley Davidson accessories and Harley Davidson parts.  Additional service-driven programs are in the works and include an engine head replacement program.

For more information, visit: www.axiomcycles.com

For more information, contact:
Mark Nemets, of Axiom Cycles, 714-648-0900.  

Platinum Air Suspension

Platinum Air Suspension has designed a true rebound control air shock with the Bleed/Feed system.

One common issue with the majority of the air suspension systems in the Harley Davidson and custom motorcycle market is the pogo effect.  The pogo effect results from the lack of control on the rebound.   By having positive pressure in the shocks at all times Platinum has controlled the rebound.  Putting back pressure in both cylinders ensures the bike rides on positive pressure at all times.  An added benefit in comparison to the use of a spring and air compressor combination is the greater adjustment of ride height without sacraficing stiffnes or riding comfort.

The benefit of a fast active system is due to the use of a larger compressor.  With the use of an included wire harnes the system offers true plug and play.  Two switches allow for the control of both the seat height and stiffnes of the suspension.

As an alternative Platinum Air Suspension offers a simple system similar to other air suspension systems on the market.  What diferntiates the Platinum simple air suspension system is a tight breather muffler.  All suspension systems are available for Harley Davidson softail, V-ROD, and FLH bagger motorcycles.

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Progressive Suspension

The traditional air spring was never designed to perform the entire suspension function so Progressive Susspension utilized a traditional coil spring.  Rethinking the design of air adjustable shocks Prgressive inverted the customary function of the air chamber.  Lowers the bike is accomplished with adding air pressure.  This means that if the shock were fails, the bike would rise to full height.  The on-board air compressor allows for adjustment of both ride height and spring rate.

For Harley Davidson Touring and Baggers Progressive Suspension offers the I.A.S. system.  Utilizing both a coil and air shock the I.A.S. system offers height adjustment and spring rate tuning.  Suspension stiffnes is independent of height adjustment with dual air chambers.   With the addition of the Progressive Suspension handlebar mounted control center adjustment is made with ease at any time the rider desires.

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There are many factors affecting the safe operation of a motorcycle.  Steering problems involve the design and geometry of the front end.  "Rake" and "Trail" are the terms associated with determining a bikes rideability.  The correct amount of trail for any given amount of front end rake is essential.  It determines the stability and control of any motorcycle.  For Harley Davidson Front Ends on chopper the the trend has been to extend the length thereby increasing the trail.

The rake is the angle of your steering neck compared to a line perpendicular to the frame.  Most choppers have a rake between 34 and 45 degrees.  The trail is the distance between a line drawn through the steering neck and a line drawn vertically through the front hub at the axle.  I have read various articles on the Internet that indicate trail should be between 2-4 inches and other sites that prescribe 4-6 inches of trail.

Bikes with a high amount of rake, like say 38 degrees and up, will give even a relatively light machine a heavier feel at the handlebars due to weight of the chassis trying to self-straighten the fork as it hangs in the steering neck.  A higher degree of rake, with proper trail will give better straight-line performance, but it will feel heavier and a bit sluggish during tighter turning.

Lower rake numbers, take for instance the 26 degree frames used on Harley's big touring bikes, make the heavier machines feel deceivingly lighter than they really are.  The big bikes are much more maneuverable than, say, a raked out softail, but these bikes do not track as well at very high speeds and that's why you'll find maximum recommended speed limits for them actually listed in the Harley owner's manual.

Another thing you may notice about some Harleys upon closer inspection, is that they use raked triple trees right from the factory.   In fact, the springer models have a specific rake angle for the 21-inch wheel, and one-degree less rake built into the trees for the Heritage Springers with the larger 16-inch wheel.  During their exhaustive testing procedures Harley found the fatter-tired bike needed to be de-raked one degree to stabilize the handling.

Either way you look at it, selecting your desired rake and trail is going to be a compromise in one direction or another.  You'll either have quick handling and a little less high-speed stability, or you'll have excellent directional control at salt flat speeds with a machine that feels a little heavier as turning radii decrease.

The problems with trail arise when the rake is set at extreme angles, such as 45 degrees or more.  This is a cool look, but it creates a very long trail (pic 2).  This is usually overcome by adding some offset in the triple trees.  The offset increases the rake, but greatly reduces trail.

Adding rake to the trees can be very dangerous as it reduces the trail and can quickly lead to a negative trail situation.

In cases where a frame might have too much trail due to excessive rake, the steering can be uncontrollably heavy and needs to be held at all times at low speeds to keep the front end from "flopping" over on it's own.  Although your bitchin' new frame might be the coolest thing you've ever seen, unless set up properly, it can be very dangerous to ride.  Cases like these can usually be cured very easily with the use of fixed-rake, or adjustable-rake triple trees.

Straight pipes:  Open straight Harley Davidson exhausts perform poorly in the 2500 to 3800 rpm range.  If they are 34" or longer, they do not perform really well at any rpm.  Symptoms include missing, backfiring through the carburetor, reversion (fuel dripping out of the air cleaner) and poor acceleration.

Open mufflers:  "Gutted" mufflers with stock (or stock-like) Harley Davidson exhausts header pipes tend to perform poorly in the same rpm range as straight pipes and exhibit similar symptoms.

Long thin mufflers:  Long, small diameter Harley Davidson exhausts & mufflers with full-length baffles often exhibit the same symptoms as straight pipes, although their over-all performance may be better.

High performance 2-into-1 systems:  2 into 1 systems are often poor performers in the 2000 to 3000 rpm range.  Harley Davidson exhausts of the 2-into-1 type deliver a significant torque dip at 2500 which is slightly less than 60 mph in top gear for most stock Harley Big Twins.

Header pipe diameter:  The great majority of Harley engines, of any displacement, do their best work with 1-3/4" diameter exhaust pipes.  Larger pipes tend to suppress mid-rpm performance and, for that matter, seldom deliver the best power at high rpm either.

Header pipe length:  The stock header pipe is about 30".  Multiple tests, made by several groups, confirm this length as being very nearly the best for all-round performance.  Shorter (less than 27") and longer (over 32") header pipes significantly reduce peak power, throttle response and over-all performance.  An exception to this "rule" are a couple of the high performance 2-into-1 systems which work very well with longer (and un-even) header pipe lengths.  Stock Harley header pipes are near-perfect in diameter and length.

Muffler size:  It is not possible to make a muffler quiet, small and powerful at the same time.  One can choose power and small, quiet and small but not all three.  The reason stock mufflers are poor performers is because they are small and quiet.   However, small and loud is not a guarantee of performance.  In general, small mufflers with large straight-through, perforated tube baffles (looks like a tube with many holes drilled in it) make the most power and the most noise.  An exception to this rule (there may be more) are the popular H-D Screamin' Eagle (and Cycle Shack) small slip-on mufflers which perform very well yet are not straight-through designs.  The popular louvered core baffles restrict flow at full throttle & high rpm and reduce power a bit as a result.

Atmospheric pressure will force high pressure to low pressure.  As the piston on a two stroke engine goes up (or goes down on a four stroke engine), a low pressure is formed inside the crankcase (above the piston on a four stroke).  This low pressure also causes a low pressure inside the carburetor.  Since the pressure is higher outside the engine and carburetor, air will rush inside the carburetor and engine until the pressure is equalized.  The moving air going through the carburetor will pick up fuel and mix with the air.

Flat throttle response in the mid-rpm range is seldom caused by either an over-rich or overly lean condition.  Flat mid-rpm performance is more likely due to the effects of the cam or exhaust design.  If the needle size is incorrect, it will normally reveal itself as poor mileage (too rich), slow warm-up (too lean) or light detonation when accelerating moderately from around 2500 to 2900 rpm (again, too lean).

Carburetor troubleshooting is simple.  With basic principles and concepts understood you are half way to getting the optimal results from your machine.  The first step is to find where the engine is running poorly.  It must be remembered that carburetor jetting is determined by the throttle position, not engine speed.  If the engine is having troubles at low rpm (idle to 1/4 throttle), the pilot system or slide valve is the likely problem.  If the engine has problems between 1/4 and 3/4 throttle, the jet needle and needle jet (most likely the jet needle) is likely the problem.  If the engine is running poorly at 3/4 to full throttle, the main jet is the likely problem.

A typical FXD (either engine type) motorcycle will deliver around 45 mpg at 65 mph on a flat, windless road.  A heavy touring machine (FLHT- series) may be down a few mpg from that standard.  Fuel mileage in the 30s indicates a rich condition.

Confusing symptoms is one of the most common errors in diagnosing carburetor tuning inaccuracies.  For instance, low power at 60 mph (2500 rpm) in top gear may have one or more of several causes: The exhaust system may not work well at that rpm, the cam design may not work well at that rpm, the ignition timing could be incorrect for that rpm, or, --- the carburetor could be set too lean or too rich at that throttle opening.

Notice that when the carburetor was mentioned above, it is the throttle opening we refer to and not the rpm.  This is an important difference.  The Roll-Off technique is the quickest and is almost as accurate as the Roll-On method.  First, one gets the engine warm on the way to a safe roadway.  If there is room, use fourth gear as this allows more time to assess the result.

Now, get the engine rpm high enough that it is on the cam and in its power band.  This may need to be as high as 4000 rpm with some cam choices.  Apply full throttle.  Let the engine accelerate for a couple of seconds until it has settled in and is pulling hard.  Quickly roll the throttle off to about the 7/8ths position.  When you do this, the mixture richens slightly for a second or so.  If the engine gains power as you roll the throttle off, then the main jet is too small and you need to fit a larger one.  If the engine staggers slightly or has a hard hesitation, then the main jet is too large and you need to fit a smaller one.

While the performance of other engine components depend, to a large extent, upon rpm, the carburetor only responds to the position of its throttle valve (slide) and the amount of air flowing through it (and sometimes the direction of that air flow).  One of the most valuable carburetor tuning aids is to change rpm (down or up shift) while holding the same road speed.  An example: The engine gives poor acceleration from 60 mph (2570 rpm) in top gear.

If you maintain the road speed and down shift to fourth gear, the throttle setting will remain essentially the same but the engine rpm will increase 20%.  If the poor top gear acceleration is due to, say, poor exhaust system performance at that rpm, then, the problem will either go away, get better or at least change its character.  If, on the other hand, the problem is carburetor tuning, the poor acceleration will remain the same because the carburetor throttle opening is the same.

The most crucial part of the beak in of any engine including those from S&S is the first 50 miles.  It is during these miles that engine damage will occur if not ridden properly.   First and foremost do not exceed 2500 RPM and do not lug the engine for the first 50 miles.  In other words stay in the lower gears.  Vary the RPM.   Vary the load.  Do not hold the RPM steady for any length of time.  Stay off the freeway.  If it is really hot day wait till it cools down.   Excessive engine temperature is damaging particularly for the high performance engines of today such as S&S.  A common myth is that using synthetic oil during breaking reduces the necessary wearing.   This has not been proven.  After the first 50 miles change the oil to remove any debris.

Run the engine no higher than 3500 RPM for the next 500 miles.  Again vary the RPM and load.  Avoid steady speeds and do not lug the engine.   After 500 miles we recommend changing the engine oil, transmission oil, and primary oil if running a wet clutch.

The next 500 miles increase the RPM without hitting the rev limiter.  Continue to vary the RPM and be conservative.  Operate at normal highway speeds.   Do not engage in drag racing, dyno runs, and excessive speeds.  After 1000 miles if you have a carbureted bike check the jets and make appropriate adjustments.   Change the engine oil.  Your engine is now broken in.

To assist the wearing in of the piston rings the surfaces on new or overhauled cylinders are honed with abrasive stones.   This process of producing a rough surface on the cylinder walls is known as cross-hatching.  A series of minute peaks and valleys cut into its surface exist on a cylinder that has been cross hatched.

The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall.   When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects.   Each tiny groove acts as the oil reservoir holding oil up to the top level of the groove where it then spreads over the peak surface.   The piston ring must travel up and down over this grooved surface, and must "hydroplane" on the oil film retained by the grooves.   Otherwise, the ring would make metal-to-metal contact with the cylinder wall and the cylinder would quickly wear out.

However the ring will only ride on this film of oil if there is sufficient surface area to support the ring on the oil.   When the cylinders are freshly honed the peaks are sharp with little surface area.  Our goal when seating the rings on new steel cylinders is to flatten out these peaks to give more surface area to support the rings, while leaving the bottom of the groove intact to hold enough oil to keep the surface of the cylinder wet with oil.   See illustration.  At the point where the top of the peaks produced by the honing operation become smooth and the tapered portion of the piston ring wears flat break in has occurred.

When the engine is operating, a force known as Break Mean Effective Pressure or B.M.E.P is generated within the combustion chamber.   B.M.E.P. is the resultant force produced from the controlled burning of the fuel air mixture that the engine runs on.   The higher the power setting the engine is running at, the higher the B.M.E.P. is and conversely as the power setting is lowered the B.M.E.P. becomes less.

B.M.E.P is an important part of the break in process.  When the engine is running, B.M.E.P. is present in the cylinder behind the piston rings and it's force pushes the piston ring outward against the coarse honed cylinder wall.   Piston rings are designed to take advantage of the pressure and us it to push the rings out against the cylinder wall.   Therefore, as pressure builds during the compression stroke, the rings are pushed harder against the cylinder wall which aids in seating the rings.

The higher the B.M.E.P, the harder the piston ring is pushed against the wall.  The surface temperature at the piston ring face and cylinder wall interface will be greater with high B.M.E.P. than with low B.M.E.P.   This is because we are pushing the ring harder against the rough cylinder wall surface causing high amounts of friction and thus heat.

The primary deterrent of break in is this heat.  Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface.   This glaze will prevent any further seating of the piston rings.  If glazing is allowed to happen break in will never occur.   Also, if too little pressure (throttle) is used during the break-in period glazing will also occur.

We are not here to purport that the advice given in this article is the last word.  It is solely the accumulated knowledge of experience, obtaining information from manufactures such as S&S, Crane Cams, speaking with factory team mechanics, and reading as much published text as we were able to get our hands on from sources such as S&S.

Speaking with S&S it is clear engine break in is not something to take lightly.  Whether it be a brand new Harley Davidson or a re-built S&S Evo break in determines maximum horsepower the engine can generate and the amount of oil the engine will consume.   The initial five hundred miles of an engine's life have a major impact on how the engine will perform and ultimately the life of the engine.

First a little background.  Break in is the process of seating the compression rings to the cylinder walls.  It is the physical mating of the engine's piston rings to it's corresponding cylinder wall.   Achieving a good compatible seal between the piston rings and the cylinder wall is done through the initial wearing of the rings and cylinder.  In turn this reduces the amount of combustible gases escaping the combustion chamber past the piston rings into the crankcase section of the engine.

The term blow by was coined to refer to the escaping gas.  Reducing blow by enables the engine to run cleaner and cooler.  Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil.   The piston rings serve a few purposes.  Among these purposes is managing the amount of oil present on the cylinder walls and sealing the gases within the combustion chamber.   Without the rings seating properly excessive amounts of oil will accumulate on the cylinder wall surfaces.  Every time the cylinder fires this oil is burned.   Add to this blow by induced engine breathing and you have the engine consuming oil.

Breaking in an engine is a process.  Manufactures such as S&S and Crane Cams by their very nature are very conservative in their advice.  They also tend to keep it simple which for a lot of things in life is usually good.   Manufacturers advice on break in, with minor variation, is to keep the RPM low for the first 1000 miles, change the oil after 1000 miles, and then gradually raise the RPM.

In our opinion and others such as S&S and Crane Cams lugging an engine by keeping the RPM too low is equally bad if not worse then the advice to run the engine as hard as you usually do when riding.   Lugging the engine or using low power will not expand the pistons rings to the degree required to avoid forming a film on the cylinder walls.   This film is referred to as glazing and the only method to remove it is to re-hone the cylinders by removing them.   This can be a very expensive job.  The break in process stops with the result of excessive oil consumption when the cylinders are glazed.

Engine break in is separated into two parts.  Initial pre-ride and the first 1000 miles.

To ensure the head gaskets do not fail the initial start up is important.  Run the engine approximately one minute at 1250-1750 rpm.   Do not crack throttle or subject the engine to any loads during this period.  Check the oil pressure and ensure it is normal.  Verify oil is returning to the oil tank, and that no leaks exist.

Shut off the engine.  Check for leaks or other problems.  It is important to let engine cool to the touch.  After the engine has cooled, start up again and allow the motor to build some heat.   The Engine should be run no longer than three to four minutes.  When the cylinders become warm or approximately 150 degrees shut the motor down and let it cool to room temp.  Check for leaks and verify oil is returning to the oil tank.

Repeat this procedure 3 or 4 times.  Each successive time let the engine run a little hotter, 10 degrees or so.   Apply a little more throttle each run up to 2500 on the last cycle.  If running a carbureted bike do not attempt to set the best idle speed and mixture at this time.   Get these setting close.  Until the engine is operating at normal running temperatures these settings can not be dialed in.   Also do not let the engine temperature become excessive.  For most garage mechanics as my wife says, take it outside.   After the last cycle allow the engine to cool to room temperature.  Check for leaks.

Your bike is now ready for the second part of the break in ... 

The classic Harley springer fork appeared as standard issue on the thousands of Flatheads and Knuckles produced through the middle of the 20th century.

I was fitted to the 45 cubic inch built during World War II functioning well under the adverse conditions.

When servicemen returned home hey adopted the classic Harley with its springer fork and fatbobs as their transport of choice.   The motorcycles were inexpensive and readily available.   With the advent of motorcycle clubs members began building the first choppers.   Lopping off Harleys standard hulking great mudguards and dual seats the custom Harley fatbob with it's springer front end was created.   In "The Wild One" Lee Marvin's Flathead easily out does Marlon Brando's stock Triumph in terms of cool.   It may have been slower and more of a handful to ride but it was definately cool.

In 1991, The Dyna line of Harley-Davidson's was introduced with the FXDB Dyna Glide Sturgis.   1994 saw the jump of Harley-Davidson into the Superbike racing with the VR1000.   The VR1000 featured a dual overhead cam and a liquid cooled engine and showed that Harley-Davidson was not fully averse to manufacturing a race inspired sport bike.   In 1996 a state of the art Parts and Accessories distribution plant was opened in Franklin, Wisconsin.   The following year a new Product Development Center opened in Milwaukee.   Also in 1997, a 330,000 square foot plant in Kansas City made its first Sportster.   In 1998, assembly operations were taking place in another part of the world, Brazil.   In the year 2001 Fuel injection was available on the Softail models.

Harley was forced to endure another bad period throughout the 1950's.   The Brittish owned 40 % of the motorcycle market with their Triumph.  In 1957 Harley introduced the Sportster, the fastest Harley ever.  A great bike.  It was fast, nimble, and easy to ride.  Just like the English motorcycle industry, Harley stuck to its expertise, style and character.

Due to the enormous attack on the motorcycle market from the Japanese, the English disappeared without a trace and the American were almost dead.   Even the Shovelhead couldn't save Harley.   1969 Harley merged with the American Machine and Foundry Company (AMF).   The result of this decision was that the quality decreased enormously and the Super Glide and the SLCR Caféracer of 1970's got a bad name.

The beginning of the 1970's saw a revolution of the Harley-Davidson.   In 1971, the cruiser was born.   This machine united a sporty front end with the frame and power train of the FL series.   1973 saw the move of assembly operations to a new 400,000 square foot plant in York, Pennsylvania.   The year 1975 was the first of four consecutive years that the Harley-Davidson won the AMA Grand National Championships in dirt track racing.   In 1977, the FXS Low Rider and the FLHS Electra Glide Sport were introduced to the public.   The FXS featured a special lower seat position which resulted in the distinguishing term Low Rider.   The FLHS was a low cost base line FLH Electra Glide with modifications intended to make the model sportier.

The beginning of the 1980's saw another change in the partnership of the engine and transmission.  In 1980, the FLT model was born with a 5-speed transmission hard bolted to the engine.  Also this year, the drive train was replaced with a Kevlar belt.  In 1981 senior members of Harley-Davidson bought back Harley-Davidson Motor Company from AMF.  In 1982 Harley-Davidson enacted the Materials as Needed (MAN) application in their production.  This would cut production costs and improve the quality of the parts.  In 1983 the group H.O.G was founded and became the largest factory-sponsored motorcycle club in the world.

In 1984 the 1340 cc V-twin engine was introduced, seven years in the making.   With this engine was able to create a modern motorcycle, which was still a Harley Davidson.   Also this year, the Softail model became available.    The Softail was most primarily distinguishable by hidden rear shock absorbers.   In 1987 Harley-Davidson began its "Buy Back Program" which offered full trade in value within two years on certain models.   Also at this time, the Harley-Davidson Company obtained a place on the New York Stock Exchange for those interested in taking a financial stake in the company.   In 1988 Harley-Davidson celebrated their 85th Anniversary in Milwaukee, an event that brought forth 60,000 aficionados of the Harley-Davidson.   At the end of this revolutionary decade for Harley-Davidson, the FXSTS Springer Softail model was introduced into the lineup.   The FXSTS Springer Softail was a modern day recreation of the 1940's Harley-Davidson.   It had the classic biker look with the 1340 cc engine symbolizing the new era of Harley-Davidson.

This motorcycle was initially built for racing and was powered by a one-cylinder gasoline combustion engine.

Bill Harley and Arthur Walter Davidson in 1903 developed a one-cylinder motorcycle in Milwaukee.  It was a reliable and even a beautiful cycle.  After selling the first one in 1905 they had made 11 more motorcycles, in 1908 it was 154.  The company operated out of a little wooden barn, that was build by Davidson's father.  The small company extended quickly and another member of the Davidson family, William, joined them.  As the company grew they hired about 20 employees moving from the barn to a build stone factory building.  In 1909 Bill Harley made a project of the first 1000 CC V-Twin.  It produced a modest seven horsepower.  The 45-degree V-twin would become one of the more recognizable images of the Harley-Davidson motorcycle.  This V-Twin has stayed with HD.  A little known fact is Harley-Davidson didn't invent the V-twin.  When Bill Harley developed one, he just followed others of the time.

The "Bar and Shield" logo that has become legendary was introduced in 1910.   Placed on their motorcycles to this day is symbolizes Harley Davidson.   With numerous first place winnings in races, endurance contests and hill climbs Harley-Davidson received recognition as a builder.

The "F-head" engine was introduced in 1911.  This engine was the power workhorse until 1929, when the "Flathead" engine was introduced.

Harley-Davidson continued to grow with over 200 dealerships by 1912.  Construction began on a new 6-story factory.   Harley-Davidson also became an exporter this year and their first overseas sale was made in Japan.   The side car was added in 1914 and Harley Davidson formally put their hand in the ring of motorcycle racing.   Within a few short years they dominated the sport and become known as the "Wrecking Crew".   The three-speed sliding-gear transmission was introduced in 1915.   In 1917, one-third of all Harley-Davidsons were sent overseas to the U.S. Military to fulfill their patriotic call and to aid in the war effort.   The following year, roughly half of the motorcycles produced were sold to the U.S. military.   In the end, about 20,000 motorcycles were used in the war, most of them Harley-Davidsons.   By 1918 Harley-Davidson was the biggest motorcycle factory in the world with nearly 2,000 dealerships worldwide.

The 1920's saw changes to the appearance of Harley Davidson motorcycles.   One such change was the identifiable teardrop shape gas tank.   The single-cylinder engines were re-introduced in 1926 after having been discontinued in 1918.  In 1928, the first twin-cam engine and front wheel brakes were available on the Harley-Davidson.  With this modification, the motorcycle could reach speeds in excess of 85 mph.

The 1930's and subsequent years saw more record breaking and award winning Harley-Davidson's.   The three-wheel Servi-Car was introduced in 1932 becoming a familiar commercial and police vehicle for years to come.   Along with appearance changes such as the "eagle" design, which was painted on all Harley-Davidson gas tanks, changes were also made to the engine.   The biggest Harley, the 1340 CC appeared in the mid 30's.   This motorcycle became Harley Davidson's trademark. 1936 also became a milestone.   That year the Knucklehead was launched and with this motorcycle Harley Davidson was able to claim victory over the Indian.