2.8 MOTOAMERICA TWINS CUP TECHNICAL SPECIFICATIONS
The following rules are intended to give freedom to modify or replace some parts in the interest of safety, research and development and improved competition between various motorcycle concepts.
EVERYTHING THAT IS NOT AUTHORIZED AND PRESCRIBED IN THIS RULEBOOK IS STRICTLY FORBIDDEN
If a change to a part or system is not specifically allowed in any of the following articles, then it is forbidden
Twins Cup motorcycles require a MotoAmerica homologation. (See MotoAmerica homologation procedure for Twins cup). All motorcycles must comply in every respect with all the requirements for road racing as specified in these technical regulations.
Once a motorcycle has been homologated, it may be used for racing in the corresponding class for a maximum period of twenty (20) years or until such time that the homologated motorcycle is disqualified by new rules or changes in the technical specifications of the corresponding class.
The appearance from the front, rear and the profile of the Twins Cup motorcycles must (except when otherwise stated) conform in principle to the homologated shape (as originally produced by the manufacturer). The appearance of the exhaust system is excluded from this rule.
2.8.1 Motorcycle specifications
All parts and systems not specifically mentioned in the following articles must remain as originally produced by the manufacturer for the homologated motorcycle.
2.8.2 Engine configurations and displacement capacities
The following engine configurations comprise the Twins Cup class.
Over 600cc up to 750cc 4 stroke 2- cylinder water cooled
Over 600cc up to 800cc 4 stroke 2- cylinder air cooled
Modifying the bore and stroke to reach class limits is not allowed. All machines must be
normally aspirated.
2.8.3 Balancing various motorcycle concepts
In order to equalize the performance of motorcycles used in the Twins Cup Championship, a system of performance enhancements or restrictions can be developed (such as minimum weight, air restrictors or REV limits may be applied according to their respective racing performances). The decision to apply a balancing system to a motorcycle will be made by the MotoAmerica Permanent Bureau based on decisions made by the Technical Director at any time deemed necessary to ensure fair competition.
For 2021: See MotoAmerica Technical Bulletin 02-2021 for Aprilia RS660 engine restrictions.
2.8.4 Minimum weight
2.8.4.1 The minimum weight will be:
Over 600cc up to 800cc 135 kg (297.6 lbs.)
At any time during the event, the weight of the whole motorcycle (including the tank
and its contents) must not be less than the minimum weight.
There is no tolerance on the minimum weight of the motorcycle.
During the final technical inspection at the end of each race, the selected motorcycles
will be weighed in the condition they finished the race and the established weightPage 108 of 179
limit must be met in this condition. Nothing may be added to the motorcycle. This
includes all fluids.
During the practice and qualifying sessions, riders may be asked to submit their
motorcycle to a weight control. In all cases, the rider must comply with this
request.
The use of ballast is allowed to stay over the minimum weight limit and may be
required due to the handicap system. The use of ballast and weight handicap
must be declared to the Technical Director at the preliminary checks.
2.8.5 Numbers and number plates
The background colors and figures (numbers) for the Twins Cup are blue (pantone 281c) background with white numbers:
The allocated number (& plate) for the rider must be affixed on the motorcycle as
follows:
a. Once on the front, either in the center of the fairing or slightly off to one side. The
number must be centered on the blue background with no advertising within 25 mm
in all directions.
b. Once, on each side of the motorcycle. The preferred location for the numbers on
each side of the motorcycle is on the lower rear portion of the main fairing near the
bottom. The number must be centered on the blue background. Any change to this
position must be pre-approved a minimum of two (2) weeks before the first race by
the Technical Director.
c. The numbers must use the fonts as detailed after Art 2. Any numbers not using
these fonts must have the design of the numbers and the layout pre-approved by
the Technical Director a minimum of two (2) weeks before the first race. All digits
must be of standard form.
d. Any outlines must be of a contrasting color and the maximum width of the outline is
three (3) mm. The background color must be clearly visible around all edges of the
number (including outline). Reflective or mirror type numbers are not permitted.
e. Numbers cannot overlap.
In case of a dispute concerning the legibility of numbers, the decision of the
Technical Director will be final.
The sizes for all the front numbers are: Minimum height: 140 mm
Minimum width: 80 mm
Minimum stroke: 25 mm
Minimum space
between numbers: 10 mm
The sizes for all the side numbers are: Minimum height: 120 mm
Minimum width: 70 mm
Minimum stroke: 20 mm
Minimum space
between numbers: 10 mm
2.8.6 Fuel
a. The designated fuel is VP Racing Fuels MGP.
b. Please refer to Article 2.10 for additional details
2.8.7 Tires
a. The maximum number of tires, of any type, available to each rider during the event will be specified in Article 2.3.7.1.
b. A maximum of six (6) tires per rider can be mounted at any time.
c. For the race only, wet tires will not need to be marked with a tire sticker. They will not be considered in the total number of tires available for use; however, normal allocation limits still apply.
d. During free practices, qualifying practices, warm-up sessions and races, front and rear tires are required to be marked with tire stickers
e. See article. 2.3.7
2.8.8 Engine
2.8.8.1 Fuel injection system
2.8.8.1.1 Fuel injection systems refer to throttle bodies, fuel injectors, variable length intake tract devices and fuel pumps.
a. The original homologated fuel injection system must be used without any
modification with the following exceptions:
i. Air funnels may be modified.
ii. Throttle bores may be modified.
iii. Butterfly valves may be modified to fit increased throttle size but must include
the same safety features as stock.
iv. Secondary throttle valves and shafts may be removed or fixed in the open position and the electronics may be disconnected or removed.
b. The fuel injectors must be stock and unaltered from the original specification and
manufacture.
c. Variable intake tract devices cannot be added if they are not present on the
homologated motorcycle and they must remain identical and operate in the same
way as the homologated system. All parts of the variable intake tract device must
remain exactly as homologated.
d. Air and air/fuel mixture must go to the combustion chamber exclusively through the
throttle body butterflies.
e. Electronically controlled throttle valves, known as ‘ride-by-wire’, may be only used if
the homologated model is equipped with the same system. Software may be
modified but all the safety systems and procedures designed by the original
manufacturer must be maintained.
2.8.8.2 Cylinder head
The cylinder head must be the originally fitted and a homologated part. The following
modifications are allowed:
a. Porting and polishing of the cylinder head normally associated with individual tuning
such as gas flowing of the cylinder head, including the combustion chamber, is
allowed. Welding is not allowed. No machining or modification is allowed in the cam
box / valve mechanism area.
b. The throttle body insulators may be modified.
c. Modifications of the inlet and exhaust ports by taking off or adding material (welding
is forbidden). Epoxy may be used to shape the ports.
d. Surface grinding of the cylinder head surface on the head gasket side
e. Original homologated valve guides may be replaced. Page 110 of 179
f. Polishing of the combustion chamber is allowed.
g. Original valve seats must be used, but modifications are allowed to the shape.
h. Compression ratio is free, but the combustion chamber may be modified only by
taking material off.
i. It is forbidden to add any material to the cylinder head unless as described above.
j. Rocker arms (if any) must remain as homologated.
k. The valves may be replaced but the valve face must remain the same diameter as
homologated.
l. Valve springs may be changed but the number must remain as homologated.
m. Valve spring retainers, collets and/or spring seats may be altered or replaced.
n. The shim buckets / tappets must remain as homologated.
2.8.8.3 Camshaft
a. Camshafts may be modified or replaced (see article 2.8.8.2 a).
b. At the technical checks: for direct cam drive systems, the cam lobe lift is measured;
for non-direct cam drive systems (i.e. with rocker arms), the valve lift is measured.
2.8.8.4 Cam sprockets or gears
a. Cam sprockets may be slotted to allow the adjustment of cam timing.
b. Pressed on cam sprockets may be replaced with an adjustable boss and cam
sprocket.
c. The cam chain must remain as homologated.
d. Cam chain tensioner may be replaced.
2.8.8.5 Cylinders
a. Cylinders may be bored to a maximum of 2mm over standard bore or up to a
maximum total displacement of 700 cc, whichever is less. Machines with a standard
displacement greater than 700cc must remain as homologated.
b. Cylinder coatings must remain as homologated or replaced with a steel sleeve.
2.8.8.6 Pistons
a. May be modified or replaced
2.8.8.7 Piston rings
a. May be modified or replaced
2.8.8.8 Piston pins and clips
a. May be modified or replaced
2.8.8.9 Connecting rods
a. Connecting rods may be altered or replaced from those fitted to the homologated
motorcycle.
b. The material must be the same type as the homologated item (e.g. steel, titanium,
alloy) or steel.
c. If the original homologated connecting rod is not fitted with a little end insert, then
the replacement connecting rods may be fitted with an insert of any material.
d. The center to center (little end to big end) length of the rod must be the same as the
original homologated item.Page 111 of 179
e. Connecting rod bolts are free.
2.8.8.10 Crankshaft
Only the following modifications are allowed to the originally fitted and homologated
crankshaft:
a. Bearing surfaces may be polished.
b. Surface treatments may be applied to the crankshaft.
c. Balancing is allowed but only by the same method as the homologated crankshaft.
For example, heavy metal (e.g. Mallory metal inserts) is not permitted unless
originally specified in the homologated crankshaft.
d. The reduction in weight of the crankshaft can be no higher than 5% of the
homologated weight without the tolerance as shown on the homologation drawing of
the crankshaft.
e. There is no limit to the addition of crankshaft weight.
f. The balancing must be performed by the original method (e.g. drilling or machining)
and in the same position (e.g. edge of counter weights).
g. Polishing of the crankshaft is not allowed.
h. The balance shaft must remain as homologated. No modifications are allowed.
2.8.8.11 Crankcase / Gearbox housing
a. Crankcases must remain as homologated. No modifications are allowed (including
painting, polishing and lightening).
b. Bolt-on brackets and/or bracing may be added internally to the crankcase to
increase strength, however welding on the crankcase and external bracing is not
allowed.
c. It is not allowed to add a pump used to create a vacuum in the crankcase. If a
vacuum pump is installed on the homologated motorcycle, then it may be used only
as homologated.
2.8.8.11.1 Lateral covers and protection
a. Lateral (side) covers may be altered, modified or replaced (excluding pump covers).
If altered or modified, the cover must have at least the same resistance to impact as
the original one. If replaced, the cover must be made in material of the same or
higher specific weight and the total weight of the cover must not be less than the
original one.
b. Titanium bolts may be used to fasten lateral covers.
c. Oil containing engine covers cannot be secured with aluminum bolts.
d. All lateral covers/engine cases containing oil, and which could be in contact with the
ground during a crash, must be protected by a second cover made from metal such
as aluminum alloy, stainless steel, steel or titanium. Each side (left and right) of the
engine must have at least one (1) protective cover installed on the farthest
protruding engine cover containing oil. Composite covers are not permitted. FIM
approved covers will be permitted without regard of the material or dimensions.
i. The secondary cover must cover a minimum of 1/3 of the original cover. It must
not have sharp edges that could damage the track surface. Covers must be
fixed properly and securely with a minimum of three (3) case cover screws that
also mount the original covers/engine cases to the crankcases.
ii. Heavy duty engine case covers may be used in lieu of secondary case covers. Page 112 of 179
e. The Technical Director has the right to refuse any cover not satisfying this safety
purpose.
2.8.8.12 Transmission / Gearbox
a. The stock transmission shafts and gear set only are permitted. Shimming is allowed.
b. Undercutting and surface treatments are permitted.
c. OEM shift drum detent stars may be modified or replaced.
d. Quick-shift systems are allowed (including wire and potentiometer).
e. The countershaft sprocket, rear wheel sprocket, chain pitch and size may be
changed.
f. The sprocket cover may be modified or eliminated.
g. The chain guard may be removed.
2.8.8.13 Clutch
a. The clutch system (wet or dry type) and the method of operation (by cable or
hydraulic) must remain as homologated.
b. Friction and drive discs may be changed.
c. Clutch springs may be changed.
d. The original clutch assembly (including the clutch basket) may be modified or
replaced by an aftermarket unit. The maximum retail price of the complete assembly
is €1200. The clutch may include back torque limiting capabilities (slipper type).
e. No power source (i.e. hydraulic or electric) can be used for gear selection if not
installed in the homologated model for road use. Human power is excluded from the
ban.
2.8.8.14 Oil pumps and oil lines
a. The originally fitted and homologated oil pump may be modified but the oil pump
housing, mounting points and oil feed points must remain as original.
b. Oil lines may be modified or replaced. Oil lines containing positive pressure, if
replaced, must be of braided reinforced construction with swaged or threaded
connectors.
2.8.8.15 Cooling System
a. The only liquid engine coolant permitted is water.
b. Protective meshes may be added in front of the oil and/or water radiator(s).
c. The cooling system hoses and catch tanks may be changed.
d. The radiator fan and wiring may be removed. Thermal switches, water temperature
sensors and thermostats may be removed inside the cooling system.
e. The radiator may be changed with an aftermarket radiator or additional radiator.
f. Oil coolers may be modified. Heat exchangers (oil/water) may be replaced with an
oil cooler.
g. Oil coolers must not be mounted on or above the rear fender.
h. The radiator cap is free.
2.8.8.16 Air box
a. The air box design is free but must be able to allow the engine to operate in all
climatic conditions at all times (i.e. rain should not stall the engine).
b. The air box drains must be sealed.
c. Ram air tubes or ducts running from the fairing to the air box may be modified,
replaced or removed.
d. All motorcycles must have a closed breather system. All oil breather lines must be
connected and discharge in the air box.
e. Additional heat shielding is allowed (i.e. gold or silver heat tape).
2.8.8.17 Fuel supply
a. Fuel pumps must remain as homologated.
b. The fuel pressure regulator may be modified or replaced.
c. Fuel lines from the fuel tank up to the injectors (fuel hoses, delivery pipe assembly,
joints, clamps, fuel canister) may be replaced and must be located in such a way
that they are protected from crash damage.
d. Fuel petcocks may be altered, replaced or removed from those fitted to the
homologated motorcycle.
e. Quick connectors or dry break connectors may be used.
f. Fuel vent lines may be replaced.
g. Fuel filters may be added.
2.8.8.18 Exhaust system
a. Exhaust pipes, catalytic converters and silencers may be altered or replaced from
those fitted to the homologated motorcycle. Catalytic converters must be removed.
b. The number of the final exhaust silencer(s) is free.
c. For safety reasons, the exposed edge(s) of the exhaust pipe(s) outlet(s) must be
rounded to avoid any sharp edges.
d. Wrapping of exhaust systems is not allowed except in the area of the rider’s foot or
an area in contact with the fairing for protection from heat.
e. The noise limit for the Twins Cup will be 107 dB/A (with a three (3) dB/A tolerance
after the race only) except for where local rules prevail.
2.8.9 Electrics and electronics
2.8.9.1 Ignition / Engine Control System (ECU)
a. The engine control system (ECU) may be modified or replaced with the following:
i. The original and homologated ECU with or without software changes and /or
FIM/DWO/MotoAmerica approved external ignition/ injection module(s). Price
limit €1500 (tax and OEM ECU price excluded but includes software, upgrades/
flashes)
ii. A MotoAmerica approved race ECU. For the race ECU to be approved the retail
price including software, any activations and upgrades or necessary hardware
(e.g. ignition driver and lambda modules) must be less than: €1500 excluding
data logger or €2750 including data logger
iii. The maximum total price of other active/control/calculation units such as lambda
driver modules, quick shifters, analogue to CAN, air bleed control, dash and
ABS defeat modules and traction control units is €750. These devices must be
approved by FIM/DWO/MotoAmerica.Page 114 of 179
b. For the ignition and or injection module, or quick shifter to be approved, samples
must be sent by the manufacturer of the device to the Technical Director with
technical data and selling price.
c. Optional equipment sold by the motorcycle manufacturer for the homologated model
is considered not homologated with the bike and must follow the requirements for
approved electronics/data loggers.
d. During an event, the Technical Director has the right to ask a team to substitute their
ECU or external module with the sample received from the manufacturer. The
change must be done before Sunday warm-up.
e. No extra sensors may be added for control strategies except shift rod sensors,
wheel speed sensors and lambda sensors.
f. Other additional electronic hardware equipment not on the original homologated
motorcycle cannot be added with the exceptions noted below.
g. The characteristics of approved data logging systems must be the following:
i. The maximum retail price of the unit (hardware + software, excluding sensors
and wiring harness) cannot exceed €3000 (tax excluded) if it is a standalone unit
and €3750 (tax excluded) if combined with the ECU.
ii. The data logger unit must be available for sale to the public.
iii. A maximum of seven (7) simultaneously working sensors (connected to the
additional data logger) may be added to the original sensors on the motorcycle.
iv. The sensors must be simple-function.
v. Approved data loggers with internal inertial platforms (IMU or gyros) may be
used for data collection but may not be used for control strategy. Also see
2.6.9.1/i./vii.
vi. Type of sensor is free.
vii. Communication from the ECU to an approved data logger (logger can receive
data only; no data transmission is allowed) is allowed without any limitation in
CAN channel logger number.
h. The addition of a device for infra-red (IR) transmission of a signal between the
racing rider and his team, used exclusively for lap timing, is allowed and considered
in the seven (7) sensors.
i. The addition of a GPS unit for lap timing/scoring purposes is allowed and
considered in the seven (7) sensors.
j. Telemetry is not allowed.
k. No remote or wireless connection to the bike for any data exchange or setting is
allowed whilst the engine is running or the bike is moving.
l. Harness:
i. Wiring harness is free.
m. The original speedometer and tachometer may be altered or replaced.
n. Spark plugs may be replaced.
o. The central unit (ECU) may be relocated.
p. The battery is free.
2.8.9.2 Generator, alternator, electric starter
a. The generator (ACG) must remain as homologated; no modifications are allowed.Page 115 of 179
b. The flywheel may be modified or replaced.
c. The ACG must generate sufficiently to maintain battery charge.
d. The stator must be fitted in its original position and without offsetting.
e. The electric starter must operate normally and always be able to start the engine
during the event.
During parc fermé, the starter must crank the engine at a suitable speed for starting for
a minimum of two (2) seconds without the use of a boost battery. No boost battery may
be connected to the machine after the end of the session.
2.8.10 Main frame and pre-assembled spare frame
a. During the entire duration of the event, each rider can only use one (1) complete
motorcycle, as presented for technical control, with the frame clearly identified with a
seal.
b. In case the frame needs to be replaced, the rider or the team can request the use of
a spare frame to the Technical Director.
c. The pre-assembled spare frame must be presented to the Technical Director to
receive the permission to rebuild the motorcycle. The pre-assembly of the frame
shall be strictly limited to:
i. Main frame and swing-arm
ii. Bearings (steering pipe, swing arm, etc.)
iii. Rider controls (handle bars, rear sets, shift/brake linkage), front and rear mud
guard.
iv. Rear suspension linkage and shock absorber
v. Upper and lower triple clamps, front forks, braking system and wheels.
vi. Wiring harness, ECU, dash associated electronics, throttles, airbox and
associated cables.
d. The spare frame will not be allowed in the pit box before the rider or the team has received authorization from the Technical Director.
e. The motorcycle, once rebuilt, must be inspected before its use by the technical stewards for safety checks and a new seal will be placed on the motorcycle frame.
f. No complete spare machine may be at the track. If found, penalties will be applied. For the remainder of the event the machine will be impounded and no part of that machine may be used for spare parts.
See 2.5.10 for a complete explanation of procedures
2.8.10.1 Frame body and sub-frames
a. The main frame must remain as originally produced by the manufacturer for use on the homologated machine.
b. Gussets or tubes may not be added or removed; other modifications are allowed within the following section of these rules. Brackets may be welded or bolted to the main frame for the purpose of constructing a detachable front or rear sub-frame or attaching fairings. These brackets may not be used to change the rigidity of the main frame. (See 2.8.10.1/ j)
c. Holes may be drilled in the frame only to fix approved components (i.e. fairing brackets, steering damper mount).
d. The engine must be mounted in the homologated position.
e. Suspension linkage mounting points on the frame must remain as homologated.
f. If the homologated machine has exchangeable bearing inserts/ bushes:
i. The bushings/inserts are free to make the above adjustment and the homologated
position is considered as the position in which the production motorcycle is supplied.
g. If the homologated motorcycle has fixed bearing positions for the steering stem:
i. Steering angle changes are permitted by fitting inserts onto the bearing seats of the
original steering head. The original bearing seats may be modified (ovaled) or
increased in diameter to insert special bushings. No part of these special bushings
may protrude axially more than three (3) mm from the original steering head pipe
location nor may the bearing be inset.
h. All motorcycles must display a vehicle identification number punched on the frame
body (a proper “legal VIN” which the Technical Director may choose to append). No
detachable plates are permitted.
i. No polishing or surface refinishing is allowed but the paint scheme is not restricted.
j. The front and rear sub frame may be changed, altered or removed. If the rear sub
frame is integral to the main frame, additional seat brackets may be added and nonstressed protruding brackets may be removed if they do not affect the safety of the
construction or assembly. Rear sub frames that are integral to the main frame may
be removed and replaced with a detachable sub-frame. Titanium or composites may
not be used for the construction of the subframe. Bolt-on accessories to the rear
sub-frame may be removed. Also see 2.8.11/f.
k. Approved sub-frames will be permitted without regard of the material.
2.8.10.2 Suspension – General
a. Participants in the Twins Cup class must only use the approved and listed
suspension units for that season.
b. The approved products from the manufacturers must be available to all participants
at least one (1) month before the first round of the Twins Cup season and remain
available all season. The products must be available within six (6) weeks of a
confirmed order.
c. Setting parts and tuning parts must be provided by the suspension manufacturers to
all customers/teams/participants using the manufacturer’s products. These parts
can be used by all participants during the season. These parts shall be available for
immediate delivery to all teams/customers.
d. Teams may not modify any part of the forks or shock absorber; all setting parts must
be supplied by the suspension manufacturer and available to all teams/riders.
e. The suspension manufacturers are allowed to offer service contracts when the team
is using the approved and listed suspension products. The suspension
manufacturers cannot demand a service contract for a customer or participant in
order to obtain a suspension product.
f. Electronically controlled suspension must be removed.
2.8.10.3 Front suspension
a. The front fork in whole or part may be changed but must be the same type as the
homologated (leading link, telescopic, etc.).
b. Forks from the Twins Cup approved list, or from any other FIM homologated
Supersport or Superstock 1000 machine, may be used.
c. The upper and lower fork clamps (triple clamp, fork bridges) and stem may be
changed or modified.Page 117 of 179
d. A steering damper may be added or replaced with an after-market damper.
e. The steering damper cannot act as a steering lock limiting device.
2.8.10.4 Swing-arm (rear fork)
a. The rear fork must remain as originally produced by the manufacturer for the
homologated motorcycle.
b. The rear swing-arm pivot position may be modified by use of a modified pivot bolt
(smaller or elongated) but the frame must remain as homologated. If the standard
bike has inserts then the orientation/position of the original insert may be changed
but the insert cannot be replaced or modified.
c. Rear wheel stand brackets may be added to the rear fork by welding or by bolts.
Brackets must have rounded edges (with a large radius). Fastening screws must be
recessed. An anchorage system or point(s) to keep the original rear brake caliper in
place may be added to the rear swing-arm.
d. The rear axle chain adjuster may be modified or changed.
2.8.10.5 Rear suspension unit (shock)
a. The rear suspension unit may be changed but a similar system must be used (i.e.
dual or mono).
b. The rear suspension linkage may be modified or replaced.
c. The original fixing points on the frame (if any) must be used to mount the shock
absorber, linkage and rod assembly fulcrum (pivot points).
d. Removable top shock mounts may be replaced. If replaced, they must retain their
homologated geometry.
2.8.10.6 Wheels
a. Wheels may be replaced (see article 2.3.4) and associated parts may be altered or
replaced from those fitted to the homologated motorcycle.
b. OEM wheels that do not meet the size requirements must be replaced.
c. Aftermarket wheels must be made from aluminum alloys.
d. The use of the following alloy materials for the wheels is not allowed: Beryllium
(>=5%), Scandium (>=2%), Lithium (>=1%).
e. Each specific racing wheel model must be approved and certified according to
JASO (Japanese Automotive Standards Organization) T 203-85 where W
(maximum design load) of art. 11.1.3 is 195 kg for the front wheel and 195 kg for the
rear wheel; K = 1.5 for front and rear wheels. Static radius of tire: front 0.301 m, rear
0.331 m.
f. Wheel manufacturers must provide a copy (or copies) of the certificate for their
wheel(s) as proof of compliance to the Technical Director when requested.
g. The homologated wheel and sprocket carrier assembly may be used with no
modification, irrespective of material.
h. The wheels may be overpainted, but the original finish cannot be removed.
i. On motorcycles equipped with a double-sided swing arm (rear fork), the rear
sprocket and brake rotor must remain on the rear wheel when the wheel is removed.
j. Bearings, seals, and axles may be altered or replaced from those fitted to the
homologated motorcycle. The use of titanium and light alloys is forbidden for wheel
spindles (axles).
2.8.10.7 Brakes
a. Participants in the Twins Cup season may use the following front brake parts:
i. The originally fitted and homologated front and rear master cylinder and calipers
ii. The front and rear master cylinder and calipers from an FIM homologated
Supersport or Superstock 1000 machine
iii. The front and rear master cylinder and calipers from the Twins Cup approved list
iv. Any combination of the above
b. The approved products from the manufacturers must be available to all participants
at least one month before the first round of the MotoAmerica Twins Cup season and
remain available all season. The products must be available within four (4) weeks of
a confirmed order.
c. No parts can be added to the approved list during the current season. Performance
related updates are not allowed. Any product changes due to manufacturing or
material supply issues must be approved in advance.
d. Front and rear brake calipers, as well as all the mounting points and mounting
hardware (mount, carrier, hanger), must remain in the homologated position (see
also article 2.8.10.4 c). When using brake systems from other homologated
machines you may use the same mounting technique that the systems originated
from. (i.e. rear brakes may be converted to underslung if the caliper was made for
that purpose and vice versa)
e. Brake pads or shoes may be altered or replaced from those fitted to the
homologated motorcycle.
f. Brake hoses and brake couplings may be altered or replaced from those fitted to the
homologated motorcycle. The split of the front brake lines for both front brake
calipers must be made above the lower fork bridge (lower triple clamp).
g. Only steel (max. carbon content 2.1 wt. %) is allowed for brake discs.
h. The ABS system must be removed.
2.8.10.8 Handlebars and hand controls
a. Handlebars may be replaced.
b. Handlebars and hand controls may be relocated.
c. Throttle controls must be self-closing when not held by the hand.
d. Throttle assembly and associated cables may be modified or replaced but the
connection to the throttle body and to the throttle controls must remain as on the
homologated motorcycle.
e. The clutch and brake lever may be replaced with an after-market model. An adjuster
to the brake lever is allowed.
f. Switches may be changed but the electric starter switch and engine stop switch
must be located on the handlebars.
g. Motorcycles must be equipped with a functional ignition kill switch or button
mounted on the right-hand handlebar (within reach of the hand while on the hand
Wheel rim diameter size (front and rear): 17 inches
Front wheel rim width: 3.50 inches
Rear wheel rim width: 5.25-5.5 inches
grips) that is capable of stopping a running engine. The button or switch must be
RED.
2.8.10.9 Footrest and foot controls
a. Footrests, hangers/brackets and hardware may be replaced and relocated but the
hangers/brackets must be mounted to their original frame mounting points.
b. Foot controls, gear shift and rear brake must remain operated manually by foot.
c. Footrests may be rigidly mounted or a folding type which must incorporate a device
to return them to the normal position.
d. The end of the foot rest must have at least an eight (8) mm solid spherical radius.
e. Non-folding footrests must have an end (plug) which is permanently fixed, made of
aluminum, plastic, Teflon® or an equivalent type material (minimum radius 8 mm).
The plug surface must be designed to reach the widest possible area. The
Technical Director has the right to refuse any plug not satisfying this safety purpose.
2.8.10.10 Fuel Tank
a. The fuel tank must be the originally fitted and homologated part with no modification
allowed.
b. All fuel tanks must be completely filled with fire retardant material (i.e. fuel tank
foam).
c. Fuel tanks with tank breather pipes must be fitted with non-return valves that
discharge into a catch tank with a minimum volume of 250cc made of a suitable
material.
d. Fuel caps may be changed. Fuel caps, when closed, must be leak proof.
Additionally, they must be securely locked to prevent accidental opening at any
time.
e. A rider spacer/pad may be fitted to the rear of the tank with non-permanent
adhesive. It may be constructed of foam padding or composite material.
f. The tank may have a fitted cover.
g. The sides and rear of the fuel tank may be protected with a cover made of a
composite material.
2.8.10.11 Fairing / Bodywork
a. The fairing and body work may conform in principle to the homologated shape as
originally produced by the manufacturer or replicate any full fairing type motorcycle
within the following limits:
i. No wings or winglets
ii. No excessive aerodynamics that may interfere with the safe operation of the
motorcycle
b. The use of carbon fiber or Kevlar® materials is not allowed in fairing, fuel tank
cover, seat, seat base and associated bodywork construction. Specific
reinforcements in Kevlar® or carbon are allowed locally around holes and stressed
areas.
c. “Naked” or fairing-less is acceptable but must have a belly pan that conforms with
2.8.10.11 (e)(f).
d. The windscreen may be replaced or added if not originally equipped.
e. The original air ducts running between the fairing to the airbox may be altered or replaced from those fitted to the homologated motorcycle.Page 120 of 179
f. The lower fairing must be constructed to hold, in case of an engine breakdown, at least half of the total oil and engine coolant capacity used in the engine (min. 5 liters). The lower edge of openings in the fairing must be positioned at least 50 mm above the bottom of the fairing.
g. The lower fairing must incorporate one hole of 25 mm in the bottom of the front lower area. This hole must remain closed in dry conditions and must be only opened in wet race conditions, as declared by the race director.
h. The front fender design and material are free but no excessive aerodynamics that may interfere with the safe operation of the motorcycle. The decision will be made by the Technical Director and is final.
i. The rear fender design and material are free, may be added or removed. No excessive aerodynamics that may interfere with the safe operation of the motorcycle. The decision will be made by the Technical Director and is final.
2.8.10.12 Seat
a. The seat may be altered or replaced from those fitted to the homologated motorcycle.
b. The top portion of the rear body work around the seat may be modified to a solo seat.
c. Holes may be drilled in the seat or rear cowl to allow additional cooling. Holes which
are bigger than 10 mm must be covered with metal gauze or fine mesh. Mesh must
be painted to match the surrounding material.
d. Material of construction of the seat may be altered or replaced from those fitted to
the homologated motorcycle.
2.8.10.13 Rear safety light
All motorcycles must have a functioning red light mounted at the rear of the
machine. This light must be switched on any time the motorcycle is on the track or
being ridden in the pit lane and the session is declared WET. All lights must comply
with the following:
a. Lighting direction must be parallel to the machine center line (motorcycle running
direction) and be clearly visible from the rear at least 15 degrees to both the left and
right sides of the machine center line.
b. The rear light must be mounted near the end of the seat/rear bodywork and
approximately on the machine center line, in a position approved by the Technical
Director. In case of dispute over the mounting position or visibility, the decision of
the Technical Director will be final.
c. Power output/luminosity equivalent to approximately: 10 – 15 (incandescent), 0.6 –
1.8 W (LED).
d. The output must be continuous; no flashing safety light is allowed whilst on track.
Flashing is allowed in the pit lane when the pit limiter is active.
e. The safety light power supply may be separated from the motorcycle.
f. The Technical Director has the right to refuse any light system not satisfying this
safety purpose.
2.8.10.14 Fasteners
a. Standard fasteners may be replaced with fasteners of any material and design.
b. Aluminum fasteners may only be used in non-structural locations.Page 121 of 179
c. Titanium fasteners may be used in structural locations but the strength and design
must be equal to or exceed the strength of the standard fastener it is replacing. See
article 2.8.10.6/j.
d. Special steel fasteners may be used in structural locations but the strength and
design must be equal to or exceed the strength of the standard fastener it is
replacing.
e. Fasteners may be drilled for safety wire, but intentional weight-saving modifications
are not allowed.
f. Threads repairs may be made using inserts of different material such as Helicoils
and Timeserts.
g. Fairing/bodywork fasteners may be changed to the quick disconnect type.
2.8.11 The following items MAY BE altered or replaced from those fitted to the
homologated motorcycle
a. Any type of lubrication, brake or suspension fluid may be used.
b. Gaskets, seals and gasket materials
c. Bearings (ball, roller, taper, plain, etc.) of any type or brand may be used.
d. Instruments, instrument bracket(s) and associated cables
e. Painted external surface finishes and decals
f. Material for brackets connecting non-original parts (fairing, exhaust, instruments,
etc.) to the frame (or engine) cannot be made from titanium or fiber reinforced
composites except the exhaust silencer hanger that may be in carbon.
g. Protective covers for the frame, chain and footrests may be made in other materials,
like fiber composite material, if these parts do not replace original parts mounted on
the homologated model.
2.8.12 The following items MAY BE removed
a. Instrument, instrument bracket and associated cables
b. Tachometer
c. Speedometer and associated wheel spacers
d. Chain guard
2.8.13 The following items MUST BE removed
a. Headlamp, rear lamp and turn signal indicators (when not incorporated in the
fairing). Openings must be covered by suitable materials.
b. Rear-view mirrors
c. Horn
d. License plate bracket
e. Tool box
f. Helmet hooks and luggage carrier hooks
g. Passenger foot rests
h. Passenger grab rails
i. Safety bars, center and side stand brackets welded to the main frame may be
removed.
