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GPS Racing/BST Carbon Fiber Flat Track Wheels
When races can be won or lost by hundredths of a second, you need the world’s finest flat track wheels. Lighter and stronger than conventional materials, carbon fiber improves handling by reducing rotating mass.
Our Carbon Fiber Flat Track Wheels are a collaboration between two companies: GPS Racing and BST. BST of South Africa is recognized as the world’s premium manufacturer of motorcycle carbon fiber wheels.
Designed specifically for flat track, GPS Racing’s Proprietary billet hub system is incorporated with BST’s carbon fiber spoke and rims.
Due to its rigorous manufacturing and safety standards, GPS Racing/BST is the only carbon fiber wheel currently allowed in AFT (American Flat Track) competition.
ADVANTAGES OF CARBON FIBER WHEELS
Carbon fiber wheels are not only lighter than conventional wheels, they are lighter where it counts. Most of the weight saving is near the outside of the wheel in the critical rim and spoke areas.
By lightening the perimeter of the wheel, rotational inertia is reduced improving control, acceleration, and braking.
Weight is reduced without compromising strength by combining woven and unidirectional carbon material to form a monocoque (single unit) design with hollow spokes. This technique produces a wheel strong enough to exceed stringent (US) DOT (Department of Transportation) and (Japan) JWL (Japan light alloy wheel standard) safety standards. The JWL is the most stringent wheel standard in the world.
HOW DOES IT IMPROVE PERFORMANCE?
Weight saving on our carbon fiber wheels works like this:
- The Outer Rim area affects 85% of the overall performance of the wheel – Our carbon fiber wheels are lighter in the rim area
- The Spokes affect 10% of the overall performance of the wheels – Our carbon fiber spokes are lighter than conventional wheels
- The Hub center only affects 5% of the overall performance of the wheels
Our wheels have reduced weight where it increases performance most – a feat which is achieved because they are engineered to maximize carbon fiber’s properties of high strength and low weight in the critical spoke and rim area. If you reduce weight in the CORRECT places, you save on rotational inertia – and physics takes care of the rest.
BENEFITS OF REDUCING ROTATIONAL INERTIA
- Improves throttle control
- Increases braking response
- Improves top speed
If you want detailed information about the effects of inertia on motorcycle wheels, like what E=1/2 m v2 + ½ J w2 means, then check out “The Effects of Inertia” on the Technical tab above.
All Carbon Fiber Wheels are sold complete with hub adapters, bearings (installed), spacers, and hardware.
All wheels include hub adapters with outboard bearings for maximum rigidity.
For reduced friction, optional ceramic bearings are available. The reduced friction will free up rear wheel horsepower.
Our wheel spacers are designed to capture the hub’s floating center spacer, holding it in place when the axle is removed and installed.
Front Carbon Fiber WHeel comes with standard hub adapters.
A Front Carbon Fiber Wheel with two (2) front standard hub adapters is 4.50 wide measured at the axle entry and exit point.
- 2.15 (WM3) x 19”
- 2.50 (WM4) x 19”
- 2.75 (WM4.5) x 19”
- 3.00 (WM5) x 19”
Bolt-on and pull-thru hub styles are available. Both styles include knock-off nuts for quick changing of sprockets and disc brakes.
Available wheel sizes:
- 2.15 (WM3) x 19”
- 2.50 (WM4) x 19”
- 2.75 (WM4.5) x 19”
- 3.00 (WM5) x 19”
- 3.50 (WM6) x 19”
Rear Wheel with Quick Change Bolt-On Adapters
Bolt-On Adapters attach to the hub using 8 machined bolts. Adapters are precisely machined to save weight while maintaining strength. Wheels are available with universal symmetrical hubs or are model specific. If you don’t see the width you need, contact us. Custom widths are available.
All wheel sizes are available with these rear hubs:
- 6.25” Wide
- 6.50” Wide
- 7.25” Wide
- 8.00” Wide
- Honda CRF450
- Yamaha YZF450
Rear Wheel with Quick Change Pull-Thru Reversible Adapters
The pull-thru reversible design allows turning over the rear tire without removing it from the rim. Instead of bolting to the hub, pull-thru adapters attach to the hub using one of the knock-off nuts. Unscrew one knock-off nut and in less than 30 seconds you can reverse the direction of the tire.
Reversible adapters are only recommended for DTX rear wheel setups where the right and left side are different widths. If the right and left adapters are the same width, we recommend using bolt-on adapters. All Wheel widths are available with these rear hubs.
- Honda CRF450
- Yamaha YZF450
Quick Change Rear Disc Brake Mount
- For Yamaha 10.5” disc brake with 6 point attachment
19″ Carbon Fiber (2.15 – 3.50 width) 6.25 – 6.875 lbs
Comparison to Conventional Spoke Wheel
3.00 x 19” Carbon Fiber Wheel vs 3.00 x 19” Sun rim with Barnett Style hub:
- 6 1/2 lbs vs 9 3/8 lbs
The conventional wheel is more than 44% heavier than the GPSR/BST Carbon Fiber Wheel
GPSR/BST Carbon Fiber wheels utilize BST’s monocoque carbon fiber rim and spokes bonded to GPSR’s Proprietary Billet Tough Hub system. All adapters, spacers, and bearings used with our billet Tough Hub will also work with our Carbon Fiber wheels.
BST uses preimpregnated carbon fiber composites in both a woven and unidirectional format. The fibers are oriented in the direction of stress to increase strength. Engineers can increase the wall thickness where required and reduce thickness where it is not necessary.
Using a monocoque (single unit) design further reduces weight while increasing strength over conventional designs. BST has a patented process for the manufacture of a monocoque hollow spoke wheel.
The preimpregnated carbon fiber is ideally suited for wheels:
- Damage Tolerance: Similar to aluminum
- Strength: Better than aluminum
- Stiffness: Similar to aluminum
- Corrosion resistance: Totally corrosion free
- Chemical resistance: Resistant to most dilutants such as acetone, benzene, and thinners. Limited resistance to brake fluids and acids
- Max structural temperature: 212 degrees Fahrenheit
- Min structural temperature: -40 degrees Fahrenheit
- Max operating temperature: 176 degrees Fahrenheit
Wet Lay-Up Versus Preimpregnated Manufacturing Process
In the wet lay-up process, the carbon fiber material is laid into the mold dry and resin is applied with a brush. This is a less expensive and less precise method of manufacturing. The parts are normally heavier and the fibers can distort during the lamination process.
BST wheels are manufactured using the preimpregnated process. In the preimpregnated process, resin is applied by machine onto the fibers in a thin film. Following the layup, the wheels are then cured in an Autoclave in a high pressure and temperature controlled environment which ensures the consolidation of all the layers, resulting in a strong, rigid monocoque structure.
Compared to the wet lay-up process, preimpregnated carbon fiber can have 10% – 20% better laminate properties at a lower weight. This preimpregnated and Autoclave process is the same process used to manufacture Formula 1 race car chassis (tubs).
EFFECTS OF INERTIA
For detailed information, read BST’s The Effects of Inertia pdf.
For more information about BST, visit their website blackstonetek.com
Q: What safety ratings do GPS Racing (GPSR)/BST carbon fiber wheels have?
A: GPSR/BST wheels pass (US) DOT (Department of Transportation) and (Japan) JWL (Japan Light Alloy Wheel Standard) safety standards. Japan’s JWL is generally acknowledged as the world standard for wheels. The JWL is the most stringent wheel standard in the world.
Q: How tough are GPSR/BST Carbon Fiber wheels?
A: GPSR/BST wheels exceed international JWL (Japan Light Alloy Wheel Standard) safety standards which include an impact test. Contrary to rumor, a properly designed carbon fiber wheel has resilient properties. Check out the impact test video! Click Here to see test video.
Q: What torque should I use when fitting the hub adapter to GPS Racing (GPSR)/BST wheels?
A: There are eight 5/16-18 machined SHCS (socket head cap screws)per hub adapter (16 total per wheel). Torque them to 175 in/lbs. (14.5 ft./lbs.) Make sure the bolts are free of grease or oil, and fasten them with blue Loctite #24240.
Q: How do I tighten and remove the quick change ‘knock-off’ nuts?
A: GPSR has two styles of knock-off nuts available: a 2-wing and a 4 pin round. Special knock-off wrenches are required to tighten and remove the nuts. GPSR Manufactures a Hybrid Billet knock-off nut Wrench. The same Wrench will work with both styles of knock-off nuts.
Important note: to prevent galling, always apply a thin layer of anti-seize lubricant to the knock-off nut’s threads before tightening.
Q: Why use ceramic bearings?
A: Do you believe in magic? Ceramic bearings have much less friction than steel bearings. It requires less energy to spin the wheel and they continue to spin for a longer period of time. They reduce friction and free up horsepower. See movie to right. →
Q: How do I mount tires to carbon fiber wheels?
A: Any normal experienced shop will be able to mount tires. They should have a tire machine with plastic or rubber protectors on the clamps. If changing by hand, use nylon rim protectors to avoid scratching the clear coat finish.
Q: How are the GPSR hubs attached to the carbon part of the wheel?
A: The hubs are attached using high strength aerospace fasteners with mechanical locking mechanisms and a high strength aerospace adhesive. You should never attempt to remove them.
Q: How important is the serial number on a GPSR/BST wheel?
A: Each GPSR/BST wheel is labeled with a unique serial number. This number allows us to trace its entire history and build process. This label should NEVER be removed. Attempts to remove it will leave a very clear bare mark.
Q: How should I clean my GPSR/BST wheels?
A: Use warm water and a mild cleaner. NEVER use abrasive cleaners that will scratch the clear coat. Avoid petroleum or alcohol based products. A mild de-greaser will remove any oil. You can polish them with any normal polish for a painted surface.
Q: How does UV affect GPSR/BST carbon fiber wheels?
A: UV has little effect on GPSR/BST wheels. GPSR/BST wheels are painted with an automotive grade clear coat with UV protection. This layer protects the wheels in the same way that automotive paint protects a car.
Q: After an accident, how will I know if my wheel is still safe and usable?
A: One of the good things about carbon fiber is that you can see damage immediately. Major damage will show cracks through the rim and the wheel will not be usable. If you see no outward signs of damage after an accident, remove the tire and check the wheel carefully. Some damage is superficial: minor cracks will be visible in the clear coat, and the wheel is still usable. If the cracks are deeper and the layers of carbon fiber appear to be torn, this is more serious and the wheel should not be used.
Please contact us if you have questions. GPS Racing will offer structural stress analysis if further testing is required.
Q: Are GPSR/BST Carbon Fiber Wheels stronger than conventional wheels?
A: In an independent test performed in the UK to TUV (European Independent Test Firm) and JWL (Japan Light Alloy Wheel Standard) safety standards, a single BST wheel passed the cornering fatigue, radial fatigue, torsional fatigue, and impact test standards.
It is important to note that a single BST carbon fiber wheel passed all four of these tests. When testing alloy wheels, normally a different wheel is used for each test. A single alloy wheel would not pass all of these tests due to metal fatigue. To allow for this weakness in metal wheels, the test regulations actually specify that one new wheel for every test is permissible.
Q: How does carbon fiber compare with aluminum and magnesium alloy wheels?
A: Aluminum alloy has a high density to weight ratio (how much strength you can get per kilogram of aluminum) which makes them relatively heavy for wheels especially in the critical outer rim area.
Magnesium is a strong light material for wheels, but it has a very short lifespan, sometimes less than one season of racing. Magnesium has poor fatigue and corrosion properties and if micro-porosity occurs during the casting process, the fatigue and corrosion issues are accelerated.
In contrast, carbon fiber is lighter, stronger, fatigue free, corrosion free, and has a longer product life. As an engineering material, carbon fiber is far superior to aluminum and magnesium alloys.