HomeFeatures & ColumnsProject Formula Superbike by Phill Davis

Project Formula Superbike by Phill Davis


If you truly love high performance motorcycles, then consider yourself fortunate. Fortunate because we have the privilege of witnessing the golden age of the big-bore superbike first hand. Posterity will surely view the last 15 or so years as the greatest era of growth in the history of two-wheeled performance, and we will be able to brag to our grandkids that we were a part of it.

I still remember the first time I saw, in person, a 1986 GSXR 1100. It was so much lighter, nimbler, and more powerful than anything before it.Surely it would be the benchmark that motorcycles would forever be compared. Then came the next year.

And so it went, year after year, the ante was upped, first by one manufacturer, then another. By 1989, that same 86 GSXR 1100 was already looking like an antique. And the superbike wars were just getting going. It seems like, with the appearance of every new model year,some performance bar was being raised. Lighter, faster, bigger, quicker, no level of performance was ever good enough, or ever safe from being bested. Who could have imagined, back in 1986, just how awesome the machines rolling off of the showroom floors these days would be. I mean, you can go down to any dealership and buy a big-bore bike that is faster and more powerful than anyone, in their right mind that is, could ever need.

But being the speed junkies we are, more than we can use is never enough. So, almost before the latest models roll into dealerships, the aftermarket already has performance parts being shipped to upgrade them. First it starts with exhaust systems, jets kits, and EFI upgrade modules. Soon, pistons and cams follow. And the small motorcycle shops specializing in high performance can’t wait to get one, just so they can take apart a brand new motorcycle and see how to make it even faster. Then the bragging and posturing begin, followed by the inevitable drag race, just to prove whose bike is the baddest.





But what has always baffled me is the lack of organized drag racing for these production-based big-bore bikes. Sure, there is plenty of grudge and street racing, but no major drag racing organization has ever fielded a class to take advantage of the incredible boom of the superbike. Road racing has long had its versions of production-based racing, designed to showcase fully prepped racing machines based on bikes originally produced for the street. Formula Xtreme, AMA Superbike, and World Superbike have all been very successful, with heavy support from the manufacturers. It always seemed to me that we, as drag racers, were really missing the boat somehow. And I say this because the same bikes that were dominating the dragstrips in 1986, are still dominating the dragstrips today. Unless this changes, we can expect little growth in the factory support being given to the sport of motorcycle drag racing.

Lets face it, the GS and KZ platforms make for great drag bikes, but one of these bikes winning on Sunday does very little to help sell ZX12s and Hayabusas on Monday. Something needed to be done to stimulate the growth and development of late-model powerplants, and, in the process stimulate the interest of the manufacturers. That is why Keith “Scooter” Kizer, president of AMA/Prostar, first envisioned the Superbike class. He realized years ago that the only way to get the manufacturers truly interested in drag racing is to get drag racers to utilize the newest equipment coming out of Japan.

At first, the highly successful formula used by road racing sanctioning bodies was modified to apply to drag racing. But 750s proved to not be particularly suited to the task of drag racing, so, despite many attempts to rework the rules, the entire platform was dropped. In its place came a completely new class, drawn from a clean sheet of paper. What was needed was a class with its own identity, and to also be within reach of the average racer. So the long process of writing a new rulebook began, keeping in mind the important areas that the class needed to address. The class needed to be geared towards late-model production bikes, be financially viable to the average racer, and allow for the racer of average to above average size and riding skills to be competitive.

What resulted was the new class known as Formula Superbike. With production chassis, bolt-on swingarms, no parts-eating turbos or nitrous oxide, and many cost-limiting rules, it seemed to be the perfect solution. Not only did it create a great venue for manufacturers to support and promote their latest machines, but it also filled the void left open by the demise of Top Eliminator. You see, Top Eliminator was intended to provide an affordable head-up class of motorcycle drag racing, where the median racer could go beyond sportsman racing, without having to jump all the way into Pro Stock Or Pro Mod. He or she could learn the art of out-the-back-door racing, and hopefully use it as a stepping-stone to bigger things, without having to mortgage the farm to do it. But Top Eliminator was seriously flawed from the beginning. No rules to limit costs resulted in the class being so expensive to even get started, that most racers just stayed away. Plus with Pro Mod-like power being fed to a seven inch tire, they became a handful to ride. These hard learned lessons were fresh in the minds of the rules committee, and played a large part in the design of many rules in Formula Superbike.

But something happened in Formula Superbike’s first season. The class struggled to grow, and no one could understand why. Ongoing discussions took place throughout the year, with many ideas and opinions expressed.Prostar officials, Superbike racers, team owners, factory representatives,and members of the media all strained to explain it. And yet the question still lingers:

Why is Formula Superbike the best class in all of motorcycle drag racing that no one seems to know anything about? Is it because potential racers don’t understand the rules? Is it because they don’t believe that enough components exist in the aftermarket to build a late-model bike? Or do they just not believe that anything built later than 1985 can be turned into a dependable, fast race bike? Or maybe it is a combination of all of them. And, more importantly, what can be done to bring the class into the limelight, because the future of motorcycle drag racing, and any hopes of growing factory support, are absolutely dependant on the success of just such a class. And that is how the latest Dragbike.com project bike came to be. It was agreed by just about everyone involved that this would be the best way  to bring the class into view. By covering the buildup from start to finish, it will allow us to demonstrate, in detail, how a race bike is built. And it will allow us to explain the Formula Superbike rules and, in many cases, explain the reasoning behind the rules. It also gives a great opportunity to many manufacturers to showcase their products in a real-world setting. Not only will the products be showcased, but they will also be installed and used in actual professional competition. Our sport has no “Car Craft” or “Hot Rod” type of magazine to show the many elements that go into constructing a serious race bike. So this may well be the first time ever that such an in-depth coverage of bike construction has ever been shown.

CHOOSING THE BIKE


Once it was decided that the project would go forth, the next question to be answered was what bike to use as a platform. There were varied opinions about this subject because, while the class is intended to get the most current models on the racetrack, it is also open to most any bike built from 1986 and later. Some felt, as the rules were being written, that the class should be exclusive to only the latest models to hit the streets. But doing so risked losing a large portion of the classes potential entrants. There are already in existence so many race bikes based on slightly older chassis and power plants, it seemed foolish to disallow these bike from competing. Allowing any bike utilizing a late-model power plant to enter seemed the only smart solution. If class interest warrants it in the future, the rules can be modified over time to limit the class to only the newest machines.

So what would be most representative of the class? Would a brand-new, fuel-injected beast be what most racers chose to use, or would the more affordable older bike be the weapon of choice? High-tech vs. old-school, what should we do? So then someone suggested to perfect answer: Why not do both? We have so many aftermarket manufacturers looking to get involved, we can’t give them all an opportunity on just one buildup anyway.

And so it was decided, we would do one of each. Finding the shops to sponsor the buildups was the easy part, with both new bikes being constructed by experienced Formula Superbike competitors. Cycle Concepts in Lancaster, SC will be hosting the buildup for the first bike, and will be based on a Suzuki GSXR platform. Following the completion of the first bike, Del’s Performance Cycles in Paterson, NJ will host a buildup based on a Suzuki Hayabusa. Two very different approaches will be taken in the construction of the bikes, so it will be interesting to see what the end results will be.

While the second bike to be built has been known virtually from the beginning, the GSXR-based buildup wasn’t so clear. Originally, it was planned to use an oil-cooled (1986-1992) model GSXR, mainly because of the vast availability of aftermarket parts for these bikes. But we had a problem: We didn’t decide to do this buildup until the middle of January, leaving us only 6 weeks to construct a completely new race bike. After several days of searching, and several near-misses looking for the perfect used bike to start with, someone in the shop had an idea. Sitting right there, in the middle of the display room at Cycle Concepts, was the perfect bike. A clean, low-mileage 1997 GSXR 1100 WC was just begging to be hacked. Plus, because Cycle Concepts is specializes in the building of water-cooled GSXR’s, and we already had many parts available to us from our previous water-cooled Superbike efforts (more on this later), it only made sense to use this bike. While the new bike will ultimately be an entirely new machine, if we absolutely must, (and probably will), we can temporarily utilize some of the existing parts to make the first race.

So, about 6 hours after the decision was made, a perfectly good used street bike was turned into a bare frame and a pile of parts. Let me tell you, good air tools and a nice-sized hammer really make this job both fun and easy. From the pictures you can see what we started with, and where we are now. The photo showing the rolling chassis is for mock-up purposes, with the swingarm off of the old bike used for locating purposes. It will be necessary to rake the frame, as can be seen in the photo, to clear the exhaust system. Terry McIntosh, from McIntosh Fabrications in New Lebanon OH, will be installing a new billet steering neck, with the rake increased approximately 5 degrees over stock. Once this is back, and the new swingarm is completed, the classs assembly will begin.

In the meantime, work on the new engine and cylinder head has begun. We will be showing you some details on this in the next installment of the buildup. By the way, we will be posting a new installment approximately once a week, until the project is completed. After that, a new installment will be posted following each event of the AMA/Prostar national event tour, to allow you to follow the progress of the bike through the season. We have some really great manufacturers already on board for this project, with several others still in the works. So stay tuned, and see if we can complete the entire new bike by Gainesville.

 

 

PART 2

“So, when’s the next installment coming out?”
That’s a question I have been asked so many times this season, I can’t even count. And it is understandable why so many have asked the question, considering our intentions to complete the bike by the first race of the season. But since the writing of the first article, several unforeseen and uncontrollable situations forced us to alter our original timetable.

As the first event of the season approached, it became apparent that it was not going to be possible to have the bike completed within our limited amount of remaining time. This was due largely to the fact that many of our parts were special-ordered pieces, and there just simply weren’t enough days remaining to allow the manufacturers to deliver them to us. Thus, we found ourselves in a dilemma because, while we had an extensive project to be documented, we also had an AMA/Prostar championship to pursue.

So, with about three weeks remaining until Gainesville, we had to make the tough choice of putting aside the new chassis, and making some minor updates to our old, but proven chassis. We would then, as the season progressed and new components were received, slowly integrate the new equipment into the racing program. This would afford us a much better opportunity to test and experiment with the new parts prior to actually using them in competition.

We also decided to change the way in which the buildup would be covered on Dragbike.com. While our first intent was to cover the buildup on a day-by-day basis, we felt that a different type of approach would give the readers an easier-to-follow series of articles. Instead of day-by-day, we will be breaking up the articles into groups of related components. For instance, this installment will cover all of the basic frame and suspension components. A later article will cover the completion of the chassis, including mounting the body, brakes, etc. Down the road, the engine buildup will be covered, followed by another article covering all of the electronics.

So, now that everyone is up to date on where we have been, and where we are heading, let’s get down to the business of building a dragbike.

THE CHASSIS

As was previously mentioned, our old chassis was a proven design. When I say “proven”, I mean it had shown, over several seasons of competition, to consistently produce some of the best 60′ times in the class, and an extremely stable ride further down the track. This level of performance has come from years of experience and experimentation, and those lessons learned would help us to build an even better chassis for the new bike. But first, lets look at the somewhat unique demands that the Formula Superbike rules place on chassis design.

Unlike just about every other class in motorcycle drag racing, Formula Superbike requires that production frames be used in the construction of the bikes. So, while most other professional class drag race bikes have specialty-fabricated aftermarket frames, a Superbike has a production frame, with an aftermarket, bolt-on swingarm. By limiting these bikes toproduction frames, the cost of building a bike has been reduced. Plus, and probably more importantly, it keeps the bikes in the class more closely related to their, street-driven cousins. They have the look and “feel” of being production-based vehicles, much more so than other classes where full aftermarket frames result in bikes that only slightly resemble their original bloodlines.

Production frames are extremely strong, but they are designed to yield that strength in ways that do not necessarily reflect the needs of drag racing. That is because the high horsepower levels, combined with a sticky Mickey Thompson rear drag slick, create loads in the swingarm pivot and engine mount areas that far exceed what the factories ever envisioned their bikes needing to sustain. In order to counteract the flexing that results from this, a properly designed swingarm, with multiple attachment points and plenty of bracing, serves to greatly stiffen the stock frame.

For the construction of the swingarm, we turned to Athanas Race Chassis in Hyde Park, NY. Unlike many other chassis/swingarm manufacturers, all products from ARC are custom-built to the exact needs of the particular customer. There are no off-the-shelf components from ARC, each one is hand-built to whatever specs the customer desires. After consulting with the owner, Todd Athanas, what we came up with would be something completely new, and radically different than any other swingarm we have ever used. The swingarm would be constructed out of chrome moly tubing but, unlike most swingarm designs, it would not use heavy rectangular tubing as the main structure. Instead, it would be constructed entirely out of smaller diameter round tubing, using structural design to attain rigidity.

As you can see from the accompanying photos, what we ended up with is a very impressive piece. Instead of being just a swingarm, it is actually a complete rear frame section, similar to the back portion of a Pro Stock frame. It is bolted to the stock frame at the top in the original rear subframe holes, and is also attached at the bottom near the original footpeg mounts. This serves to transfer the load across the entire rear section of the frame, a far stronger method than just using the original shock mounts. The long runs of tubing along the top and bottom of the swingarm transfer the load of hard launches not only to the factory pivot location, but also to the top and bottom of the stock frame. Plenty of diagonals and cross braces tie together what is actually rather flimsy 1 inch diameter tubing. But despite the fact that the tubing only has a wall thickness of .058″, the structural support created by all of the bracing results in an extremely rigid unit.

Also, the pivot bolts have supports
that come both inside and outside the frame. This is to counteract the uneven load that a single-sided chain drive design places on the rear suspension. Under acceleration, the load on the chain is constantly trying to pull the sprockets together. Because this only happens on one side, the resulting load actually tries to pull the rear wheel to the left side of the bike. To understand how mounting the swingarm outside of the frame counteracts this force, consider this: Imagine standing with your feet shoulder-width apart, and having someone trying to push you from the side. It wouldn’t take much force to move you off balance. Now, move your feet to about twice shoulder-width apart, and have someone push you in the same manner. Your wider stance gives you much greater stability against this force, just as the outboard (or “clubfoot,” as this design is also known) swingarm mount gives greater stability against the uneven force of the chain.

Another advantage of this round tubing perimeter-style frame structure can be seen for the accompanying photo. When viewed from above, it is easy to see just how much room is available underneath the seat area. Compared to a rectangular-tube swingarm , the open area between the rear tire and the rear of the stock frame is massive. And we will need it, because within that area we must mount a large battery, the Schnitz Ignitions Pro Series 2 ignition controller, the Motorcycle Performance Engineering data acquisition system, and a very large oil tank for the dry sump oiling system. At the rear of the swingarm, ARC installed a set of Pro Stock-style axle block assemblies, provided by Precision
Metal Fab Racing
. PMFR manufactures a number of components for the serious drag racer, including wheels, brakes, front ends, even complete chassis for the professional class racer. Several components for this project were supplied by PMFR, but for now, lets look at the rear axle adjusters in detail. This style of axle adjusters is considerably stronger than a conventional rectangular tubing adjuster. As an additional benefit, these block assemblies allow for the rear ride height to be adjusted. This is especially helpful in this application, because the manner in which the swingarm bolts to the rear of the factory frame provides no means to adjust rear suspension height. The PMFR blocks will give us back the ability to not only fine-tune the ground clearance, but also gives us an additional method to tune the way in which the chassis reacts during hard launches at the drag strip.

To complete the rear suspension setup, ARC built a custom set of aluminum wheelie bars, which bolt into the PMFR axle adjuster rails. This setup, as pictured, including PMFR blocks, rear axle, wheelie bars, and footpeg mounts, is available from ARC for only $800 racer price. Considering the amount of detailed work involved in building this type of swingarm, plus the fact that each unit is custom-built to the customers needs, this is an absolute steal. It’s no small wonder why the majority of the bikes currently racing in the Formula Superbike class use swingarms manufactured by Athanas. Other styles of swingarms, including conventional rectangular tubing units, are also available from ARC, just call Todd to discuss your particular needs and prices.

Looking towards the front of the bike, there are almost no modifications performed to the stock frame. This is because the only allowable modifications within the rulebook are limited to bracket removal and relocation. The one exception to this is that the frame may be “raked”, which means that the angle of the steering stem may be increased. This modification is frequently performed to drag race bikes because it increases stability in the front end. It would take too much time to fully explain the dynamics of how this works, so let’s just take for granted that the higher the rake angle, the more straight-line stability will be present.

Of course, like most everything, improvements in one area usually yield reduced performance in another area. In this case, increased rake angles also result in a bike with slower, heavier steering capabilities. For street or road race use, which was the OEM’s intended use, light, nimble steering is a very important quality for their production bikes.The factories build their frames with enough rake for safe, stable operation, but no more than is necessary to maintain light steering. Drag racing has exactly the opposite needs, because the bikes simply have no need to turn. Instead, straight-line stability is of utmost importance. This need is further enhanced by the use of flimsy, soft side-walled drag slicks. These tires cause a tremendous amount of instability at the rear of the bike, and the resulting swaying and “wiggle” can cause oscillations within the chassis. These oscillations can cause “head shake”, something most experienced riders have had to deal with at one time or another. Increased rake angles help to dampen and counteract these oscillations, and reduce dangerous head shake.

Our previous chassis had the stock steering angle still in it, but it was decided that this bike would need to be raked. Not that we had ever experienced tremendous problems with head shake, but it can be a bit unnerving when the front wheel, which is carried several inched off the ground for about the first 150′, touches down at about 100mph. Because the front tire is basically not spinning when it touches, it actually skids for a brief moment when it first returns to the track. The result is a bit of nervousness in the front end, until the front tire catches up with the rest of the bike. Increasing the rake would help to counteract this problem.

But there were other reasons why the rake would be needed. As mentioned before, this bike will also have a dry sump oiling system, which we will discuss in detail later. For now, just understand that the oiling system will allow us to run a nearly flat oil pan, giving us the ability to lower the bike about 21/2 inches lower than the stock oil pan would allow. To get some idea of how low this is, take a look at the photo showing the complete roller chassis. That wood block under the frame rails is only about 31/2 inches tall, and the front wheel is still well in the air. Final ride height will place the bottom of the frame rails a mere 21/2 inches off the ground.

However, lowering the bike this much creates new problems. With the stock rake, when we shortened the forks as much as would be needed to achieve this ground clearance, the front tire got so close to the engine that the tire actually sat against the #3 exhaust tube. To further complicate things, the tire was also sitting against the bottom side of the lower triple tree. This left us no room for front suspension travel. Definitely an unsafe situation, and far short of Prostar’s required 11/2 inches of fork travel. For this new chassis, in order to take full advantage of the short oil pan, increasing frame rake would be a necessity. By increasing the rake, the front tire is moved further away from the rest of the bike, giving us back the necessary room for the exhaust, as well as the needed fork travel.

To perform the raking operation,we turned to McIntosh Fabrications. If you have never dealt with Terry McIntosh, give him a call. He does some absolutely beautiful custom fabrication work, and this rake job is no exception. The close-up photo hardly does justice to his work, you must see it in person to appreciate it. Terry doesn’t just cut out the old neck, then reweld it in a different location, but rather he completely removes the original neck. In its place, a brand new billet neck is used, complete with new bearing races already installed. Before the new neck is welded in its new position, the frame is set up in a fixture designed to keep the neck in perfect alignment. This is critical, because if the neck is not parallel with the direction of travel, a whole new set of handling difficulties could arise.

Once everything is mounted and located in the fixture, the neck is TIG-welded in position and, let me tell you, the welds are perfect. The frame is then allowed to cool while still in the fixture. This is done because twisting and distortion can occur during the cool-down process. The fixture helps the parts to maintain their alignment while the temperature of all of the various frame materials equalize temperature. McIntosh also welds new tabs onto the front of the neck to mount the headlight bracket, and also welds new steering stops. Our frame does not have the stops or the headlight tabs because we specifically requested that he not install them, due to the fact that we need them mounted in different locations from stock. But, unless you specify otherwise, these are included in the job. What you get is a frame ready to be reassembled, with little or no work required to reinstall all of the original components.

Looking again at the photo of the roller, you can probably see that the angle of the forks is increased. But also notice that, even with 5 extra degrees of rake, the front wheel still doesn’t appear to be way in front of the bike. In fact, it is about the same distance from the swingarm pivot to the front axle as it was stock. That is because practically every bit of movement forward created by the rake increase was counteracted by a set of front forks measuring just 24 inches overall length. To provide us with a set of forks this short, we again turned to PMFR. Their drag forks are absolutely the best quality available, and have been time-tested by years of use in both professional and sportsman-level racing. Each component of the fork assembly is CNC produced from billet stock, then carefully hand-assembled to the customers desired length and width.

And talk about light! The set of forks on this bike, including both triple trees, front axle, and fork brace, weighs less than 12 pounds. That is several pounds less than just one of the factory fork legs. But don’t be fooled by the light weight, they are incredibly durable. I have personally witnessed many Outlaw Pro Street bikes wheelie at 150+mph, then violently slam to the ground in a shower of sparks. I have seen several front wheels collapsed, but I have yet to see a set of PMFR forks bend.

Well that about covers it for this portion of the frame buildup. Next installment we will complete the frame by installing body mounts for the Beasley Fiberglass, tabs for sheet metal panels and inner fenders, mounting the brakes, and a whole list of small details. Until then, keep an eye on our progress!

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