Q:
How do I fit the sprocket to BST wheels?
A: The best description is on
Brocks Performance web site with detailed instructions and pics.
Thanks Brock!
The
look of BST Carbon Fiber wheels
BST wheels are hand crafted from ISO certified materials. BST's wheels
are extensively tested and there is no doubt as to their structural
integrity. We take pride in producing wheels that are as aesthetically
perfect as possible. Occasionally a wheel may exhibit slight irregularities
such as slight weave distortion, light or dark marks from resin flow
or natural porosity resulting in small 'fish eyes'. These irregularities
are acceptable by the motor industry and BST and do not affect the structural
integrity or performance in any way whatsoever. Should your wheel exhibit
such irregularities, please consider it the signature of uniqueness
- a product crafted by hand for your enjoyment.
Q:
Can I change the hubs on my wheels to fit a different bike or model?
A: BST wheels are made specifically for a type
and model of bike. Part of the manufacturing process ensures that
the wheel runs absolutely true on its own hub. The hubs have a unique
fastening system, and they must not be tampered with. So no, you
cannot change the hubs. If you are changing motorcycles, the best
solution is to sell your wheels - either separately or as a value-add
to your current motorcycle - and buy new BST wheels for your new
bike.
The
rule generally is:
HUBS
can be re-used and be fitted onto NEW Carbon Wheels (but only
the BST factory may remove the hubs)
Carbon
Blanks cannot be re-used for the purpose of putting new hubs onto
them.
Q:
Can I use tire warmers on my BST wheels?
A:
Yes you can. Make sure that the warmers and regulators are operating correctly.
Do NOT use enclosed tire warmers (side covers that blanket the entire
wheel) as this pushes the temperature higher than the specification given
on the warmers and on the BST wheels. BST wheels are designed to operate
up to 80º C which is more than adequate and will work within the requirements
of the tire warmer specifications. If used under normal circumstances,
a tire warmer set at 90º C will warm the tire accordingly, and the wheel
itself will not achieve more than 50-60º C. Carbon does not radiate the
heat as quickly as metals so there is no need to over-do it with the warmers.
Q:
How should I clean my BST wheels?
A: Use warm water with a mild cleaner, avoid petroleum
or alcohol based products and don’t use aggressive or abrasive cleaners.
A mild de-greaser will remove any oil. You can polish them with any normal
polish for a painted surface. If you want to refurbish the wheels to get
back the gloss and shine, then use a polish with a rubbing compound in
it, and complete the process with a finishing polish. USA Distributor
Motowheels uses "Plexus" to clean and "Glare" wax to protect.
Q:
How should I fit the tires to the BST wheels?
A: A normal good quality shop will be able to fit the
tires. Use a tire machine, and turn down the clamping force a touch. Don’t
use too much mounting fluid (or soap) as this can make beading more difficult.
Q:
How does the BST warranty work?
A: The BST warranty covers all workmanship for a period
of 2 years from date of sale to the rider. This is regardless of the date
on the wheels - the date on the silver sticker indicates the date of manufacture
of the carbon part. There is no shelf life for carbon fiber, so the date
does not affect the warranty.
Q:
How are the BST hubs fitted to the carbon part of the wheel?
A: The hubs are attached to the carbon fiber wheel using
a unique fastening system combining high strength aerospace fasteners
with mechanical locking mechanisms as well as high strength aerospace
adhesive.
Q:
What is the difference between the BST STREET and RACE wheels?
A: BST Street wheels are designed for normal street and
track use. BST RACE wheels have a different and lighter carbon layup,
as well as 7075 T6 aluminium hubs. These wheels are even lighter than
the standard wheels and are designed for race use only.
Q:
What sprocket can I use with my BST wheels?
A: The BST wheels come with a 5 bolt hole sprocket carrier
- the PCD of the 5 holes is 100mm and the ID is 76mm.
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. The first test is whether the tire is
holding air. If it is not, the wheel is likely damaged beyond repair.
Major damage will show cracks through the rim and the wheel will obviously
not be usable. If it holds air, remove the tire and check the wheel
carefully. Damage can be superficial in which case minor cracks will
be visible in the clear coat, and the wheel is 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 feel free to send
us photos to help assess the damage for you.
Q:
If my wheel is damaged, can it be fixed?
A: Hubs
can often be re-used if they have not been damaged. If the carbon fiber
is damaged beyond repair, you can cut the spokes close to the hub and
send the hubs to us. We will likely be able to fit them to new carbon
parts, giving you new wheels at a much reduced price. Your 'new' wheels
will carry the 2 year warranty.
If
the hubs have been damaged, the wheel cannot be recovered, as the carbon
parts cannot have new hubs attached to them.
All
repairs should be done at the BST factory.
Wheels
can also be refurbished at the factory for a very reasonable fee.
Q:
Where can I buy BST wheels?
A: BST has appointed distributors around the world. Check
out the one nearest to you at Where to Buy.
Q:
How much stronger are BST Carbon fiber Wheels than conventional wheels?
A:
BST Carbon fiber wheels have undergone an intensive programme of very
stringent testing to verify their design and to confirm their strength
and durability.
A
designated test body in the UK performed the following tests and all
tests were conducted on a single prototype wheel.
It
is important to note that this ‘single wheel test' is not usually the
case when testing a metal wheel, since due to metal fatigue behaviour
a single wheel would not last throughout all the tests. To allow for
this weakness in metal wheels, the test regulations actually specify
that one new wheel for every test is permissible, whereas in this case
a single BST wheel withstood ALL tests. A sample of test results
is given below, tests and forces exerted depend upon requirements of
the testing body (eg TÜV) and the wheel (front or rear).
- Cornering
fatigue: 1,000,000 cycles at 530Nm
- Radial
fatigue: 3,200,000 cycles at 6082Nm
- Torsional
fatigue: 1,000,000 cycles at 890Nm
- Impact
test: 337.5kg from 150mm (JWL)
The
front wheel was designed for a 150kg static load and the rear wheel
for a 250kg static load (this translates into a bike with a total dry
weight of up to 400kg). Modern sports bikes normally weigh between 160-220kg
and race bikes rarely exceed 170kg, so these static load design parameters
comfortably exceed normal conditions.
Q:
What weight are the BST wheels designed to carry?
A:
Load rating of BST wheels.
BST has derived our load specification from experience
in the field of motorcycle physics:
The load rating printed on the wheel sticker will reflect the maximum
static load/weight that is permitted on the specific wheel to not exceed
the critical loads during the dynamic situation of riding the motorcycle.
We design with a safety factor of approximately 4.
To check if the wheels are appropirate for your bike you
can use the following rules of thumb:
Scenario 1: Motorcycle
with a rider:
The usual weight distribution here is approximately 40% for the front
wheel and 60% for the rear wheel.
Total Static Weight or TSW = Weight of bike with all fluids
+ weight of rider = 220Kg + 90Kg = 310 Kg
This leaves us with the following load ratings:
For Front wheel = 310Kg x 40% = 124Kg
For Rear wheel = 310Kg x 60% = 186Kg
Scenario 2: Motorcycle
with a rider and 1 passenger:
The usual weight distribution here is approximately 37.5% for the front
wheel and 62.5% for the rear wheel.
TSW = Weight of bike with all fluids + weight of rider
+ weight of passenger =220Kg + 90Kg + 90Kg =400 Kg
This leaves us with the following load ratings:
For Front wheel = 400Kg x 37.5% = 150Kg
For Rear wheels = 310Kg x 62.5% = 250Kg
Q:
How do I set up my bike for fast road riding with BST wheels - tire pressure
and suspension settings?
A:
For road use, use the same tire pressure that you usually use. For suspension
- if the suspension is working OK for you before you put on the BST wheels,
you should not have to make adjustments. The carbon wheels make a huge
difference to the smaller bikes so there are some things you need to know.
If you get chatter on fast corners once you change to the carbon wheels
that was not there with metal wheels, you should be able to tune it out
with suspension settings, or you could add weight to the swing-arm. The
reason is simple: the total weight working on the shock is a lot less
and hence you are not working within the range of the rear shock. The
shock works at about 5 - 10 hertz and the wheel at +- 30 hertz so the
natural frequency can chase the chatter on the smaller bikes. By putting
weight on the swingarm you have the same weight working on the rear shock
while gaining the advantage of the much lighter rear wheel.
We have about ten 125 Hondas that run the wheels here in SA and they also
tend to run lower tire pressures cold as the carbon does not transfer
heat very well and they can get a bigger contact patch with lower pressure.
Q:
What torque should I use when fitting the BST wheels?
A: Use the torque as specified for the OEM
wheels. As a rule this means:
| M6
bolts |
10Nm |
| M8
bolts |
16Nm |
Make sure the bolts are free of grease or oil, and fasten
them with Locktite.
Q:
What do BST wheels include?
A: The BST wheels are designed
to fit the same way the OEM wheels fit. They are supplied with:
- All
internal bearings, spacers and seals pre-installed
- External
spacers, where required
- Air
valves
- Cush
drive (rear conventional swing arm)
- Sprocket
carrier (rear conventional swing arm) where required – wheels can be
purchased without a sprocket carrier if you wish (for race teams etc.)
- You
will need to buy a sprocket that fits the BST sprocket carrier
Q: What are the physical properties of Prepreg Carbon fiber that
make it particularly suitable for wheels?
A: Some of the properties of Carbon fiber composites
as used in BST wheels:
- Material
used - Carbon fiber Prepreg in a woven and unidirectional format,
embedded in a resin matrix, made from toughened epoxy.
- Max
structural temperature: 100 degrees C
- Min
structural temperature: -40 degrees C
- Max
operating temperature: 80 degrees C
- Corrosion
resistance: Totally corrosion free
- Chemical
resistance: Resistant to most dilutants such as acetone, benzene,
thinners,
- Automotive
fluid resistance: Limited resistance to brake fluids and acids
- Density:
Approximately 1.7 kg/qdm (Aluminium 2.7, Titanium 4.5, Steel 7.9)
- Damage
Tolerance: Similar to 2024 Aluminium
- Strength:
Better than 2024 Aluminium
- Stiffness:
Similar to 2024 Aluminium
Variable
wall thicknesses can be created anywhere as needed in order to increase
strength where required.
Fibers are oriented in the direction of stress in order to increase
strength.
BST has a patented process for the manufacture of a monocoque (single
unit) hollow spoke wheel.
Q:
What is the difference between wet lay-up and the Prepreg construction,
as used in BST wheels?
A: In the wet lay-up process, the
fibers are positioned in the mould dry and the resin is applied with a
brush. The resin is mixed by hand and mistakes can be made during mixing.
This is a relatively inexpensive process, but normally the part is heavier
and the fibers can distort during the lamination process meaning the process
is less controlled. This method does not lend itself to the Autoclave
process which cures the part under controlled heat and pressure.
In the Prepreg process used to manufacture BST wheels, the resin is applied
by machine onto the fibers in a thin film. Therefore, the resin is very
even and controlled. The parts are then cured under a high pressure and
temperature environment (Autoclave). This results in a well-compacted
laminate with better properties than with wet lay-up. Laminate properties
in Prepreg Carbon fiber can be 10%- 20% better than wet lay-up at a lower
weight (because less resin is used to do the same job). This Prepreg and
Autoclave process is used to manufacture the exceedingly strong, but light,
chassis centres (often known as ‘tubs’) for Formula 1 race cars.
Q: What performance gains can I expect on my bike by changing to BST wheels?
A:
You'll gain in many ways – this is the best performance enhancing
product you can buy. BSTs will make a dramatic difference that
will gain you speed and responsiveness with less effort and fatigue. It'll
feel like you've added a few horses to your engine – but at a very reasonable
price. Best BANG per $$ for performance …
Extra
performance:
Low mass and lowest Moment of Inertia (see our page on
The Effects of Inertia) results in a lower unsprung mass; this means
faster cornering, later braking, improved acceleration – in all, faster
lap times. Imagine the difference you'll experience from dropping 11.2
lbs off the weight of your bike! That's the difference in weight between
the standard GSXR1000 wheels and the BSTs.
Extra Riding Fun and Rider Safety:
The huge drop in weight means that handling improves dramatically
– quicker lap times with less effort and astonishing responsiveness means
less fatigue.
Extra Safety:
- Carbon fibre is a fatigue free material
resulting in longer product life;
- Carbon fiber composite is a very damage
tolerant material. In the event that a wheel is damaged, the damage
propogates less easily;
- Very low corrosion susceptibility.
Extra
Cool Looks:
Whether you are into performance or looks, this wheel
attracts attention – gleaming, black, woven-look finish and “soft” styling
makes a stunning addition to your motorcycle.
The views of UK SuperBike magazine:
"what
else can you do to a bike - for that money - to make it so much faster?"
UK
sports bike magazine, SuperBike, performed an independent two day test
at the Almeria circuit in Spain using a 2002 Honda CBR900RR (954) FireBlade.
“
The first day's testing took place with standard wheels and the only change
for the second day was the substitution of BST wheels.
Weather conditions were unchanged and the following was observed:
- Acceleration
was noticeably stronger with the rider reporting “it
felt as though it had gained ten horsepower
”
- The
bike could be braked
later
- The
bike could be turned more easily
- Top
speed
at the end of the main straight was increased
by 5mph
- Lap
times fell by a full 3 seconds – although the
rider did report “pulling the pin out” as he felt very confident on
the bike during the second day
These
results are consistent with performance gains normally found by virtue
of the combination of reduced unsprung weight and reduced rotational inertia
provided by BST wheels. Even if a bike is not being used on a circuit,
the same benefits of increased performance and rideability also apply
to road/street use. "
If
you have any further questions relating to this test or would like more
information, email the rider, Jamie Wilkins, SuperBike magazine's Road
Test Editor, on: jamie_wilkins@ipcmedia.com
Q:
How does Carbon fiber compare with Magnesium and Aluminium alloys?
A: Wheels manufactured from metal are either cast, forged,
machined, or manufactured as a combination of the three processes. Aluminium
wheels have been around for many years. They are relatively easy to manufacture
and also relatively cheap, but they are heavy because of the density to
strength ratio of Aluminium (how much strength you can get for a kilogram
of Aluminium). To improve the weight you can either choose a material that
is lighter or one that is stronger, or one that is lighter and stronger.
Using magnesium, which is lighter but not necessarily stronger, you can
improve on weight slightly.
The problem with magnesium is two fold: first - its fatigue properties are
poor and so are the corrosion properties, so a wheel may not last very long
even if perfectly cast and machined. The second problem is worse - very
often micro-porosity occurs during the casting process, which has a negative
impact on both fatigue life and corrosion. So magnesium wheels can be nice
and light but may not last very long, sometimes less than a racing season.
This makes magnesium wheels good for racing but unattractive to the man
in the street. The only solution is to find a material that is lighter,
stronger, fatigue free and corrosion free - Carbon fiber. As an engineering
material, carbon fiber is far superior to Magnesium or Aluminium alloys.
Q:
Do BST wheels have TUV certification?
A:
We achieved
TUV certification for the facility and for the wheels – GSXR1000 front and
rears, Ducati 916-998 series and 748 front and rears. TUV requires certification
per model. BST wheels passed every test. However TUV are currently writing
new specifications for carbon wheels and all manufacturers will have to
have their carbon wheels tested to the new specifications when this process
has been completed.
Q: How much safer are BST Carbon Fiber wheels than standard wheels?
A:
Carbon
fiber wheels have been around for some considerable time and have been
proven to be safe when designed and manufactured properly and, as with
any wheel, used within their design parameters. One of the parameters
is the maximum static weight of the motorcycle for which the wheel is
designed (BST sportbike wheels are designed for motorcycles that weigh
up to 280 kg dry) and have more than adequate strength and damage tolerance
for any usage within road/street, sport or race environment. Safety is
dependant on more than just strength and stiffness. Due to improved handling
and therefore lower driver fatigue and effort, BSTs make a positive contribution
towards driver safety.
