C o v e r Sto r y Motorbike

The New BMW HP2 Sport

Following the HP2 Enduro and the HP2 Megamoto, the HP 2 Sport is the third model in the High
Performance Series from BMW Motorrad featuring the boxer power unit so rich in tradition and
a wide range of innovative solutions. The new HP2 Sport is indeed the most sporting, powerful
and, at the same time, lightest production boxer of all times. Through the participation of BMW
Motorrad in the World Endurance Championships, the Company’s engineers and technicians
have been able to prove the supreme performance and high standard of the concept, at the
same time gaining experience in engine and suspension technology subsequently transferred
into series production.

 ATZ 03I2008 Volume 110

1 Short Description ing this the most powerful production Authors
boxer in the range. Maximum output of
With its dry weight of 178 kg (392 lb), the 133 hp (98 kW) and maximum engine
BMW HP2 Sport is another 12 kg (26.5 lb) speed of 9,500 rpm required complete Dipl.-Ing.
lighter than the current BMW R 1200 S modification of the valve operating sys- Peter Müller
Sports Boxer. Engine output has been in- tem. Peak torque of 115 Newton-metres/ is Director of Develop-
creased to 133 hp at 8750 rpm, with 85 lb-ft at just 6,000 rpm, on the other ment and Model Series
maximum torque of 115 Newton-metres/ hand, again reflects the practical every- at BMW Motorrad in
85 lb-ft at 6,000 rpm. Operating via drag day riding qualities so typical of a BMW Munich (Germany).
arms, two overhead camshafts on each Boxer.
side (dohc) activate the valves in the new- Interacting with the stainless-steel ex-
ly developed cylinder heads. Featuring a haust system and a three-way catalyst, Dipl.-Ing. (FH)
gearshift assistant, the new six-speed BMS-KP electronic engine management Franz Berkmann
gearbox with its tighter gear increments complete with an oxygen sensor serves to is Director of the R
allows the rider to shift up under full fulfil the European EU3 emission stand- Model Series at BMW
load without de-clutching and without ard. The high-performance engine comes Motorrad in Munich
taking back engine power. The fairing is with a compression ratio of 12.5:1 and (Germany).
made completely of carbon-fibre com- runs on premium plus gasoline (98 oc-
pound (CFP), for the first time on a pro- tane), but may also make do, thanks to
duction motorcycle with load-bearing knock control, with the usual premium Dipl.-Ing. (FH)
rear and front sections. Adjustable to a gasoline (min 95 octane). Jörg Schneppenheim
wide range of different settings, the To meet the greater requirements in is Project Manager
sports suspension as well as the adjusta- terms of engine output and speed, both HP2 Sport at BMW
ble footrests and extra-short handlebar the engine block and the cylinders have Motorrad in Munich
may be set up as required for different been appropriately modified. The new (Germany).
race tracks and for road use. Apart from cylinder heads allow the use of shorter
providing the usual information, the in- and, accordingly, more stable thread
strument cluster is also able to present rods fastening the cylinders and cylinder
lap times, the fastest lap in a given ses- heads (pull anchors). With the distance
sion, maximum engine speed, and many between the pull anchors being enlarged
other data relevant to motorsport. The in the engine block, the engine features
picture of the HP 2 Sport and technical new nikasil-coated cylinders with cylin-
data are shown by Figure 1 and Table. der liners almost twice as thick (4.2 mm/
0.17”) as usual, Figure 2.

2 Drivetrain 2.1 Crankdrive

By and large, the HP2 Sport features the
The HP2 Sport is based on the drivetrain proven crankdrive of the EVO Boxer in-
of the R 1200 S and benefits from a wide troduced in 2004 appropriately modified
range of new construction features mak- in this case in consideration of the high-

Figure 1: Sideview HP2 Sport

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Table: Specifications HP2 Sport er running loads. One such modification

is the ancillary shaft driven by the crank-
Engine shaft via a roller chain at a ratio of 2:1
Air/oil-cooled 2-cylinder 4-stroke flat twin (‚Boxer‘), two camshafts, and now incorporating sprockets with
Type
four valves per cylinder in radial arrangement, central balancer shaft
23 (previously 17) teeth serving to drive
Bore x stroke 101 mm x 73 mm
the timing chains for the camshafts. The
Capacity 1170 cm3 new roller chains with smaller chain
Rated output 98 kW (133 bhp) at 8,750 rpm units reduce friction while running and
Max. torque 115 Nm at 6,000 rpm enclose the sprockets more tightly.
Compression ratio 12,5 : 1
Mixture control Electronic intake pipe injection 2.2 Cooling
BMS-K digital engine management with overrun fuel cut-off, To cope with the higher thermal loads
Engine management
single-spark ignition acting on the flat-twin power unit also
Emission control Closed-loop 3-way catalytic converter, emission standard EU-3 under racing conditions, the principle of
Performance / Fuel Consumption combined air/oil cooling has been devel-
Maximum speed over 200 km/h oped to an even higher standard. The
Acceleration 0–100 km/h 3 sec. cooling oil ducts next to the outlet ducts
4.1 l (at constant 90 km/h) in the cylinder heads have been enlarged
Fuel consumption per 100 km appropriately, a thermostat valve open-
5.8 l (at constant 120 km/h)
Unleaded premium, octane number 98 (RON); automatic knock control ing as of an oil temperature of approxi-
Fuel type mately 95°C allowing the oil to flow into
permits operation with minimum octane number 95 (RON)
Electrical System the two oil coolers arranged parallel to
Alternator Three-phase alternator 480 W one another in the front fairing.
Battery 12 V / 12 Ah, maintenance-free To keep the frontal area and, accord-
Power Transmission
ingly, the drag coefficient of the new
HP2 Sport as low as possible, while at the
Clutch Single dry plate clutch, hydraulically operated
same time to make the cooling surface
Gearbox Constant mesh 6-speed gearbox with helical gear teeth
larger, the two oil coolers are positioned
Drive Shaft drive
behind one another. The CFP side fairing
Chassis / Brakes and the engine spoiler serve to guide the
Tubular steel space frame, front and rear made of self-supporting flow of air appropriately, thus ensuring
Frame
carbon
an optimum flow of air around the cylin-
Front wheel location / Telelever, spring pre-load continuously variable, compression damping,
suspension rebound damping and vehicle height adjustable der head.
Rear wheel location / EVO Paralever, Öhlins central spring strut, spring pre-load continuously adjus-
suspension table, rebound and compression damping adjustable, vehicle height adjustable 2.3 Valve Drive
Suspension travel front / rear 105 mm / 120 mm The most significant modification in-
Wheelbase 1487 mm volves the re-construction of the valve
Castor 86 mm operating units, where in each of the two
four-valve cylinder heads two overhead,
Steering head angle 66°
chain-driven camshafts (dohc) now oper-
Wheels Milled cast aluminium wheels
ate the valves via drag arms and polished
Rim, front 3.50 x 17”
hemispherical operating units as on the
Rim, rear 6 x 17”
new BMW K 1200 models. The camshafts
Tyres, front 120/70 ZR 17 are arranged flat in the direction of trav-
Tyres, rear 190/55 ZR 17 el and each feature one intake and one
Dual disc brake, floating brake discs, 320 mm diameter, outlet cam.
Brake, front
Brembo monobloc 4-piston caliper
To keep the combustion chambers with
Brake, rear Single disc brake, diameter 265 mm, double-piston floating caliper their central spark plug even more com-
Dimensions / Weights
pact and to improve flow conditions, the
valves come in radial arrangement. The
Seat height 830 mm
outlet valves are positioned at a vertical
Unladen weight, road ready,
199 kg angle leaning 6° to the front and the in-
fully fuelled
Dry weight 178 kg take valves lean 5° to the rear. In addition,
Permitted total weight 330 kg the outlet valves are fitted in the cylinder
head at a horizontal angle offset by 4.6° to
Usable tank volume 16 l
the top and bottom, the intake valves are
Reserve approx. 3 l
offset by 3° to the top and bottom, fitted at
Width (incl. mirrors) 750 mm
a slanted angle in the cylinder head.

 ATZ 03I2008 Volume 110

Figure 2: Full load curves HP2 Sport

The intake valves have been enlarged

in diameter by 3 mm to 39 mm (15.4“)
and the sodium-filled outlet valves are 2
mm larger, now measuring 33 mm
(13.0”) in diameter. All valves are nitride-
hardened on their seat surfaces to im-
prove their resistance to wear.
The valve guides are sintered out of
powder metal offering better anti-friction
and wear behaviour than brass guides
and therefore able to make do with small-
er overlap in the intake and outlet ducts.
Valve shaft diameter has been increased
from 5 to 5.5 mm (0.20 - 0.22”), the intake
valve seat comes in a 45°, the outlet valve
seat in a 60° angle in order to improve
the dissipation of heat. Figure 3: Cutaway drawing DOHC cylinder head on HP2 Sport
Each valve is closed by two progressive
valve strings wound in the opposite di-
rection. Two spring-loaded, hydraulic
chain tensioners and optimised guide erances in the weight of the piston are 2.5 Intake System
rails ensure the largest possible mesh ar- set off by piston pins likewise classified The newly designed airbox with its long-
ea on the timing chain gears, thus driv- by weight. The compression height of er intake funnel optimised for smooth
ing the camshafts with minimum vibra- the new pistons, in turn, is 3 millime- flow conditions increases air through-
tion and superior smoothness also at tres lower. put by 20 percent. Air entry directly into
high speeds. The intake canals are 1 mil- Due to the use of lower pistons, the the side fairing at the front right has
limetre larger in diameter and benefit connecting rods also come in different been optimised by way of CFD calcula-
from high-precision machine finish. dimensions than on the other boxer tions and tests in the wind tunnel. Par-
With the ducts being optimised in this models: The new high-strength steel- ticularly at high speeds this improves
way for perfect flow conditions right forged cracked connecting rods (36Mn- the cylinder charge cycle. The air filter
from the start, there is no need for ancil- VS4) are 3.1 mm (0.12”) longer and run is an oil-immersed and washable sports
lary spark plugs, Figure 3. in reinforced connecting rod shells in air filter also improved in its air through-
the crankshaft. On account of the long- put, Figure 4.
2.4 Pistons er connecting rods, the side forces act-
Use of forged light-alloy pistons with ing on the pistons and cylinder walls 2.6 Exhaust System
wear-reducing Grafal-coating on the are reduced accordingly, ensuring great- The exhaust system is made completely
piston shaft serves to reduce the oscil- er resistance to high running speeds of stainless steel, the exhaust manifolds
lating masses in each cylinder by ap- and less wear on both the pistons and are fitted beneath the engine for lean-
proximately 80 grams. Production tol- cylinders. ing over to a lower angle in bends and

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serving to optimise the bearing points

and the arrangement of the individual
gearbox shafts. To provide closer and
more sporting increments between the
individual gears, the first and second
gear are somewhat longer and the pri-
mary transmission ratio has been adjust-
ed to the 8 per cent increase in engine
speed (9,500 rpm).

2.8 Gearshift Assistant

The rider shifts gears on the HP2 Sport
not, as is generally the case, through a
shift bar between the foot lever and the
gearshift shaft. For instead of the usual,
rigid threaded bar, the BMW HP2 Sport
features a sliding, spring-loaded connec-
tion unit covering 3.5 millimetres (0.14”)
travel and featuring an integrated hall
IC. When shifting down, the gearshift as-
sistant behaves in the same way as a con-
ventional rigid connection. When the
rider pulls the clutch to shift up, gears
are again shifted without electronic in-
tervention via the spring in the gearshift
assistant pre-loaded at 200 N.
Should the rider not pull the clutch to
shift up, the BMS-KP engine control unit
Figure 4: Valve drive HP2 Sport will register via the hall IC fitted in the
gearshift assistant that the rider wishes
to shift up, briefly interrupting fuel in-
jection and retarding the ignition angle
in the interest of enhanced aerodynam- use. A cable then closes the flap infinite- in order to shift gears up under full load
ics, and merge into a metal-based cata- ly either in part or in full whenever re- without the rider having to take back the
lytic converter increased in diameter by quired via an electronic actuator with a gas handle manually, Figure 5.
15 millimetres (0.59“) to 105 millime- worm gearing. This is done by means of
tres (4.13“). control maps for the engine speed and
The new, particularly short interfer- throttle butterfly angle (gas lever posi- 3 Electrical System
ence pipe with its inner-mounted perfo- tion) in the engine control unit (BMS-KP)
rated cover measuring 12.5 mm (0.49”) controlling the actuator accordingly. The BMW HP2 Sport features BMW CAN-
in diameter helps to significantly in- This intentionally increases exhaust gas bus technology, just like other models in
crease engine torque at low running back-up at low and medium engine the range. The network of control units
speeds. speeds, and when quickly turning the ro- is made up of the BMS-KP engine control
The two oxygen sensors are arranged tating gas handle, thus improving the unit, the CVE Central Vehicle Electrics,
in the flow of exhaust gas upfront of the charge cycle and reducing noise emis- and the instrument cluster.
interference pipe in order to ensure a sions (EU3 standard). The BMS-KP control unit features all
particularly rapid response. The double- the control functions on HP2 Sport al-
tube rear silencer, in turn, is designed for 2.7 Clutch/Transmission ready known from BMW’s current boxer
top performance in terms of its volume In consideration of the enormous forces models. New functions are the gearshift
and pipe cross-section. This also gener- encountered particularly at the start of a assistant and the electronically operated
ates the typical “throaty” sound of the race, the friction pads on the single-disc exhaust flap. Fuel system pressure is
boxer engine coming from the silencer 180-mm (7.1“) dry clutch on the BMW 4.0 bar and is maintained consistently by
fitted beneath the seat on the load-bear- boxer models free of asbestos and heavy a mechanical fuel pressure regulator.
ing CFP rear fairing. The entry pipe lead- metals are not just riveted on to the pad In the interest of lower weight, the
ing into the rear silencer incorporates an mount, but also bonded in position. BMW HP2 Sport comes with a light
exhaust flap measuring 65.5 millimetres The transmission housing on the six- 12V/12Ah battery and a small 40A alter-
(2.58”) in diameter, a return spring open- speed gearbox with its helical gears nator. The rear light is a power- and
ing the exhaust flap in full when not in ­shifted by glide sleeves is a new design weight-saving LED light-emitting unit.

 ATZ 03I2008 Volume 110

3.1 Instrument Cluster
The instrument cluster (2D dashboard)
is able to present a wide range of infor-
mation relevant in motorsport. It may
be extended by adding a data logger, a
transponder or a GPS tracking module.
This provides the option to record data
for up to 100 laps in a racing session,
with individual laps being saved either
by the transponder or manually by
pressing the SET button when crossing
the finish line.
The row of light-emitting diodes in the
instrument cluster shows the rider the
ideal point for shifting gears and may be
freely programmed in the Race Mode. As
long as the engine is warming up, the
rider sees the appropriate, lower engine Figure 5: Gearshift assistant HP2 Sport
speed limit currently allowed, Figure 6.
Overview of the most important func-
tions:
– ROAD: Road speed, engine speed, gear and the rear light together with the num- travel, especially in extreme braking ma-
in mesh, total distance covered, trip 1, berplate support are fastened to the load- noeuvres. The sports spring struts front
trip 2, (remaining range when run- bearing rear section made of CFP. and rear feature a gas-pressure damper
ning on reserve fuel), time, stopwatch While the basic geometry of the sus- complete with a pressure reservoir in or-
– RACE: Road speed, engine speed and pension, that is the steering head angle, der to keep temperature-induced chang-
gear currently in mesh may be ex- camber and wheelbase, shows very good es in damper characteristics to a mini-
changed, number of laps, overall time, results and confirms the qualities of the mum. The system itself is filled with ni-
lap time – fastest, – last, minimum R 1200 S, it has nevertheless been slightly trogen at a pressure of 12 bar. The degree
speed, maximum speed, instant shift modified once again. The reason is that of damping in the pressure stage as well
time adjustable the fully adjustable Oehlins sports sus- as the speed of the front wheel moving
– INFO (Information on up to 100 race pension featured as standard provides in under spring pressure may be varied
laps): Lap times, minimum speed, the option to adjust the set-up to various by a knurled wheel on the pressure reser-
maximum speed, average speed, max- tracks and racing requirements. voir. In this process the piston pin diving
imum engine speed, gearshifts, throt- into the oil forces the oil through an ad-
tle butterfly, brake time 4.2 Telelever justable valve into the pressure reservoir,
– SETUP: Options for time set-up, in- Thanks to its kinematic anti-dive func- while in the rebound stage with the
stant shift time, brightness, reset, etc tion, the well-known BMW Telelever sus- spring pulling the damper piston apart
pension offers adequate residual spring the oil will flow back through the adjust-

4 Suspension and Running Gear

4.1 Frame Concept

Acting as a load-bearing element, the en-
gine/transmission unit forms the back-
bone for the suspension and running
gear. The steel front frame holding the
upper fork bridge and the front spring
strut is bolted on to the engine block.
The longitudinal arm for the BMW Tele-
lever pivots on the engine block, the cen-
tral steel tubular frame holding the
spring strut and the swinging arm
mount of the BMW Paralever is bolted on
to the engine and gearbox.
Since the HP2 Sport is for solo riding
only, there is no need for a rear frame. In-
stead, the rider’s seat, the exhaust mounts Figure 6: Instrument cluster HP2 Sport

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4.4 Wheels/Tyres
The HP2 Sport comes as standard on very
soft sports tyres measuring 120/70 at the
front and 190/55 at the rear and running
on high-strength light-alloy forged
wheels measuring 3.5 and, respectively,
6 inches in width.
Compared with cast rims, the forged
17-inch rims offering the same strength
are much more slender in design and
construction, reducing weight in each
case by 700 grams. This reduction of
weight where it really counts, at the rel-
evant point in terms of gyroscopic forces
and unsprung masses, improves han-
Figure 7: Suspension and running gear HP2 Sport dling quite significantly.

4.5 Brakes
On the front wheel a monobloc brake
able needle valve on the piston pin. The The rear-wheel suspension and damp- system from Brembo proved and tested
oil forced into the compensation reser- ing is supplemented by an Oehlins in motorsport comes with two 320-mm
voir in the inbound motion, in turn, is sports spring strut also adjustable to nu- (12.6“) stainless-steel brake discs in float-
forced back by the gas pressure via a sep- merous different positions. A further ing arrangement. The single-piece mono-
arate one-way valve. point is that ride height on the HP2 bloc structure of the radially bolted brake
The spring pre-load force may be ad- Sport may be raised also by means of callipers maintains a stable pressure
justed infinitely by two counter-locking the rear spring strut, irrespective of the point also under high thermal loads.
aluminium nuts in order to provide ad- suspension and damping set-up. To do Four pistons per brake calliper, each
equate, positive spring travel also under this, the spring strut may be extended measuring 34 mm (1.34”) in diameter,
higher front wheel loads (with a rider by up to 12 mm (0.47”) with the help of operate the sintered metal brake pads.
weighing more than 85 kg). By moving the on-board toolkit. With the spring On the rear wheel a two-piston float-
the two slide tubes down in the slide- strut pivot point being positioned about ing-calliper brake weighing only
tube holder, ground clearance on the one-third down the overall length of the 790 grams and a 265-mm (10.4”) brake
HP2 Sport at the front may be increased swing arm, this adjustment travel raises disc bolted firmly in position ensure ad-
by up to 23 mm (0.91”). This, first, ex- the rear end of the motorcycle almost equate stopping power.
tends wheel camber in the interest of 30 mm (1,18”). And contrary to the in- BMW HP2 Sport features an opti-
even greater directional stability and, crease in ride height on the front wheel, mised two-channel Bosch 8M ABS anti-
second, increases the possible side angle the increase in ride height at the rear lock brake system without an integral
in bends due to the increase in ride shortens wheel camber in the interest function. Carried over from the R 1200
height. of easier handling, Figure 7. S, this system on the HP2 Sport may also

4.3 Paralever
The BMW Paralever ensures extremely
precise and stable guidance of the rear
wheel also on the HP2 Sport. Low uns-
prung masses and low return forces un-
der load change give the rear wheel
good ground contact and, as a result,
superior power transmission at all
times. With its ratio of 1:2.75, the rear-
wheel drive does not require any service
or maintenance, with the exception of
one single oil change after 1,000 km.
With no need to lubricate, tighten or
align a chain, and with the option to
change the wheel quickly whenever nec-
essary, the rider enjoys significant ben-
efits in the pit lane thanks to the BMW
Paralever. Figure 8: FEM calculation CFP rear section or CFP Body

10 ATZ 03I2008 Volume 110

be deactivated when required. A new
feature is the pressure sensor fitted be-
tween the hydraulic unit and the front
brake callipers. The pressure sensor in-
forms the electronic control unit of the
current brake pressure every time the
brakes are applied on the front wheel,
enabling the control unit to draw pre-
cise conclusions as to surface conditions
and the risk of the rear wheel lifting off.
Such a risk is therefore determined
more reliably and the quality of the con-
trol process is enhanced significantly.

4.6 Ergonomics
The pre-forged and milled aluminium
(ALSi 1MgMn) fork bridge encompasses
the two fixed tubes through its clamp Figure 9: HP2 Sport in the 2007 Endurance World Championships
connections and rests on a ball pivot in
the front frame. The two ends of the han-
dlebar may be adjusted in their angle
versus the fixed tubes. An eccentric bush tests for air resistance, lift forces on the the air-cooled boxer concept also in inter-
enables the rider to choose either the 9° front wheel, protection from wind and national long-distance endurance racing
position conceived for the race track or weather, intake openings and cooling air (winner of the 2007 Open Class Endur-
the 6° handlebar position optimised for guidance. As a result, air resistance is ance World Championship). Now, intro-
road use. down 10 per cent versus the R 1200 S and ducing the new HP2 Sport, BMW Motor-
The brake and clutch pedal on the front-wheel lift has been reduced by an rad is able to offer the customer the most
radial hydraulic controls are adjustable even more significant 20 per cent. innovative motorsport technology in
by means of a knurled bolt for personal- The fuel tank is made of polyethylene standard trim also for road use.
ised grip width in 14 stages of 25 mm and offers a useful capacity of 16 litres Reflecting BMW Motorrad’s HP2 phi-
(0.98”) each. including 3 litres reserve. The number- losophy, the HP2 is a motorcycle built
The footrests are also made of a forged plate support complete with the direc- without compromises for its specific pur-
and milled aluminium alloy, with the tion indicator and LED rear light may be pose in a small and exclusive production
surfaces of the individual components removed very quickly and easily, just like series, Figure 9. ■
being partly polished or eloxy-plated in a the mirror, for racing on the track.
gold colour. For optimum accommoda- The load-bearing CFP rear body sec-
tion of the driver, the footrests and foot tion holding not only the rider but also
operating pedals can be adjusted inde- the exhaust system and featured for the
pendently of one another. The foot con- first time on a production motorcycle.
trols for the brake and gearshift levers has been awarded the 1st Prize 2007 by
adjust infinitely by means of an eccentric the German Industrievereinigung Ver-
adjuster, the footrests may be set to four stärkte Kunststoffe (AVK), the German
different positions by way of an eccentric Industrial Federation for Re-Enforced
mount. A special feature for racing is the Plastics.
inverted gearshift arrangement revers- Conducting elaborate FEM calcula-
ing the gearshift pattern in particular tions and optimising the CFP mat layer
for shifting up even more quickly in left- arrangement, BMW Motorrad has suc-
hand bends. ceeded in reducing the weight of this
component to just 2.5 kg. This is a weight-
saving of 40 per cent versus the covered
5 Body aluminium rear frame on the R 1200 S,
Figure 8.
All body and fairing components on the
HP2 Sport are made of multi-layer lami-
nated carbon-fibre compound (CFP) and 6 Conclusions
are constructed as load-bearing units.
The fairing has been optimised in elabo- The HP2 Sport Project has already suc-
rate CFD computations and wind tunnel cessfully proven the high performance of

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