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The conversion of a beautiful stock streetbike into a track-only racebike is an ambitious undertaking requiring a fair amount of financial and emotional fortitude. Buying a new streetbike should be an experience filled with wonder and excitement. Immediately stripping the bike down to its component parts is more demystifying than first-date sex. It’s more like first-date dissection.
Many people prefer to build a racebike slowly over time, first the bodywork, then the pipe, then the shock, etc. This approach is fine when financial restraint is dictating the engineering of the motorcycle. We try to tread a fine line between financial efficiency and performance requirements. The bikes (a Superbike GSX-R600 but mainly a Supersport trim 2003 YZF-R6) shown in this series are built to be competitive in the WERA National Endurance series. Contesting a series Championship means showing up heavy for the first round. Therefore, the bikes are built from the ground up with all required modifications over the winter months to free up summer weekends for racing or maintenance.
We usually budget about $14,000 to $16,000 to build a basic brand-new 600cc Supersport racebike. This includes the bike, bodywork, exhaust, modified shock and forks, brake upgrades, engine covers, mild engine improvements, chassis guards, steering damper, clip-ons, rear-sets, chain, sprockets, wiring supplies, fuel injection programmer, lap timer, air filter and assorted other pieces. We try to avoid low performance returns like aluminum bolts. We usually budget about 40 to 60 hours to complete the process with a fair amount of outsourcing. Performing all your own suspension work, engine work or paint work can easily double that amount of time.
If you break down the whole process into steps most of the modifications are to:
- Decrease weight
- Improve handling
- Improve reliability and safety
- Improve brakes
- Improve power
- Improve crash resistance
- Improve ergonomics
You should be able to clearly define the objective of any modification before undertaking the time and effort to effect the change. The obvious and most cited examples involve Novice racers spending money on power upgrades instead of tires and suspension. Before dropping money on some $400 part make sure you ask yourself if this part is going to quantifiably A. decrease lap times or B. make you safer (by increasing reliability). If it won’t, then don’t bother.
Most racebikes will be returned to street service before being sold. With that in mind you may want to carefully pack away all stock bodywork, lights and such and be careful about cutting electrical connectors or making irreversible modifications. Cutting the bungee hooks off of your subframe will probably not show up in your lap times and you will regret it when you try to sell the bike in two years.
You will also want to be careful in your choice of aftermarket suppliers. The participant turnover in road racing is very high. The average duration of participation in road racing is about three years. Due to this turnover some disreputable companies have been able to remain in business selling shoddy goods to racers for years. The racers who get burned once and would swear to never buy another set of crappy bodywork then leave the sport and the new kids that show up do not know that not all race tires of a certain brand are round and they sometimes fail catastrophically, that some brands of bodywork often don’t fit and may be destroyed in a single crash, that some brands of valve springs break and that some exhaust pipes are just louder, without improving performance.
Customer service, and product quality control, has suffered over the years as vendors realize they don’t have to work too hard, as there is always one more customer (mark) calling. Getting the right part, that fits, delivered to your door on-time from knowledgeable and helpful vendors is becoming an infrequent experience, perhaps because of our burgeoning economy, and greater popularity of road racing. If you find a good parts guy (male or female), or used parts vendor, or a company that makes a part that works and doesn’t break, or a supplier that can help you out with a non-standard application, do your patriotic duty and support them with all the fervor you can muster.
Ask lots of questions and trust no one. Observe with your own eyes performance, fit, function, reliability and draw your own conclusions. Being able to punch out the fairing and resume practice after sending a bike into the haybales at Memphis is preferable to reducing the fairing to several dinner-plate-sized chunks in a similar crash. Making the right choice of aftermarket vendors will greatly impact your race results.
In the interests of disclosure, some of the aftermarket products used in these articles were supplied at a discount or free due to the publicity generated by the two teams (Neighbor of the Beast and Army Of Darkness) but most of the equipment was purchased through usual racer channels. Virtually all of the suppliers used in these articles were utilized by the teams well before the teams won races. In other words, although we might have received some of the stuff free now (and not much at that), we were using the same products when we were paying for them last year. Also, you should be aware that Roadracing World will intentionally eliminate advertisers from the pages of the magazine if the editor becomes aware (usually via letters from readers) of unscrupulous business dealings. That is not to say that you are 100 percent safe shopping from the pages of Roadracing World or that you are at always at greater risk if you buy from suppliers who do not advertise in Roadracing World but you should be aware of that filter.
With those disclaimers, let’s tear down these beautiful YZF-R6 Yamahas:
In the beginning, there was the streetbike...
The first thing you want to do when you get her home is take off her clothes. Manufacturers usually use a variety of hardware to fasten the bodywork in sometimes not-so-obvious ways so you want to locate all the attachment points and identify what tool you'll need to remove a particular fastener before you start frantically pulling on stuff. Remember to unplug the electrical connectors for the turn signals before pulling the fairings all the way off, and unplug the tail light connector before removing the tail section. If you are using any amount of force to try to pull off a section of bodywork, you probably have overlooked part of the several pounds of stock fasteners.
The order in which you strip body parts off the bike is dependent upon how it was assembled, for instance if you can't get to the tail section fasteners without removing the seats, you have to remove the seats first. On the R6, we started by removing the lower fairings, including the v-shaped piece below the radiator which you may be able to leave attached to one of the fairings. Next, we removed the upper fairing, headlights, instruments, and upper fairing bracket as one piece, being careful to disconnect all the electrical plugs before pulling off the upper fairing. We then unbolted the rider's seat and removed the passenger seat and the tail section.
Sneaky hardware. Some manufacturers use these snap button type fasteners, which despite your first instinct are not removed by forceful prying by screwdriver (see “prying screwdriver = bleeding hand” in Garage article). Depressing the small button in the center with some sort of small poking device like a ballpoint pen will release the catch and then you can pull the fastener out.
We put all of the stock fasteners that we won't be using for the race bodywork into a ziplock bag and store it with the bodywork so if the bike ever goes back to street trim, you don't have to spend hours digging around the random hardware containers looking for those matching cosmetically perfect bolts when you're rebuilding it. All of the bodywork and associated hardware and cosmetic covers we pulled off this R6 fit nicely into the box our Sharkskinz race bodywork came in.
If you're painting your gas tank you'll want to drain it with a siphon hose before removing it to facilitate disassembly. Make sure you disconnect all the electrical plugs and fuel and vent hoses before lifting the tank off the frame, and watch out for pressurized fuel spraying out of the fuel line as it always seems to have the uncanny ability to find unprotected eyeballs no matter where they are looking. Or, you could be smart about it and wear some eye protection.
Since coolant isn't legal in most (if not all) race organizations and you have to take the radiator off to get to the headers anyway, drain the coolant. Even if your bike is equipped with a coolant drain plug it's often faster and easier to just pull a coolant hose off the water pump and drain it there. There have been heated debates about what is the proper way to dispose of your used coolant. Some recycling centers offer coolant recycling, but with such a small amount of coolant your city's water treatment plant is more than capable of handling your coolant processing. You can pour it down the toilet and flush it. Once you have the radiator off you can remove the cooling fan from it to save weight and, at speed, improve cooling. Be very careful with the fins on the radiator as they are easily bent.
Remove the header bolts from the exhaust studs, then unbolt the muffler from the passenger peg, and then remove the center exhaust bolt from the frame and the whole system should just drop off. You might want to support it with something under the headers when you're removing that last bolt so the exhaust system won't get crushed under its own weight like a beached whale when it hits the floor. You can then remove the passenger footpegs, and while you're at it, anything else from the subframe that you won't need such as the passenger seat mount, stock toolkit, etc. It's also easy at this point to drain the oil without fear of making a huge mess by getting oil on the stock exhaust.
Now you can remove the airbox and throttle bodies. Depending on what kind of bike you are working with you may be able to remove them as a unit. On the R6 we removed the airbox first and then took off the throttle bodies, being careful to unplug all electrical connectors and hoses, disconnect the throttle cables, and unclip the idle speed cable, before just ripping the throttle bodies out of there. Even though the head is coming off of this motor, it's good practice to tape up the intake boots, and especially the crankcase breather, to prevent the introduction of foreign objects into the motor.
Next, remove or unplug anything still connecting the motor to any other system on the bike, such as the countershaft sprocket, shifter, neutral indicator, oil pressure or level indicator, alternator, ignition pickup, clutch cable, battery leads, etc. Take a few minutes to check and double check to make sure there is nothing still attached to the motor aside from the motor mounts. When you are sure you are ready to drop the motor, loosen the motor mounts, including the motor spacers if your bike has them, but don't remove the mounts yet. Always remove the negative cable from the battery first, and then the positive cable. Assembly is the reverse of disassembly. The reason for this is to avoid the consequences of inadvertently touching a wrench to the positive terminal and the frame(dead short if the negative cable is still attached) while you are disconnecting it, if say, you are wearing a ring that is touching the wrench…
Believe us: no amount of prying or tapping or swearing will force that motor out of the frame if the motor spacers are still tight. Your typical motor spacer threads into a boss on the frame and presses against the motor, and it has notches in it that require either a manufacturer's special tool or a well-placed screwdriver to loosen. Here is what the motor spacers look like on the R6.
At this point you can suspend the front of the bike using a come-along and a couple of soft ties wrapped around the frame in such a way that leaves the triple clamps free. This allows you to bring the bike into a fully upright position so it's easier to drop the motor out. You could do this with a rearstand as well but we do it with the come-along since the next thing to come off the bike is the front end. Once you have the bike suspended you can remove the sidestand. Then, remove the motor mounts. We unbolted the front motor mounts first and then removed the long rear bolts. You want to have either some additional hands to help you lower the motor down or something under the motor like a jack to support it as you drop it from the frame. With the motor out, you can remove any superfluous hoses and anything else it doesn't need to go to the engine builder, and pack it nicely into its 2’ X 2’ plywood crate for shipping.
Since you're in the shipping mood, you'll next want to remove the forks, which is easy with the front end already suspended. Unbolt and remove the brake calipers, loosen the necessary pinch bolts, remove the axle, and then remove the front wheel. Remove the throttle sleeve, left grip, clutch perch, switch housings, and brake master cylinder from the stock clip-ons, and then remove the clip-ons and the brake system. Then you can loosen the lower triple clamp pinch bolts, and then the upper triple clamp pinch bolts, and slide the forks out of the triple clamps.
You should end up with something like this, a far cry from that gorgeous streetbike of a few hours ago. It is perfectly normal to feel a little regretful and nervous at this point.
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