There comes a point when even a retro styled machine needs to be refreshed. The question becomes how to do it. To paint a scenario and stick within the Honda stable, imagine one day there is a retro version of the Honda Interceptor 750 circa 1983. It isn’t an unlikely scenario as that first Interceptor launched a thousand riding dreams and looked at the time like nothing else on the road. If that bike was given a retro treatment today, what would its refreshes look like? If continuous and sustained would they eventually make their way back to the VFR800 we have today? That is all a little too Days of Future Past. The point is that you can not refresh a retro machine in a new direction from what eventually came after it originally. In the case of Honda’s CB1100 retro flagship, the refreshing is best described as subtle – which is the best course of action. Noticing the differences is like playing that game on the back of a kid’s menu involving spotting the ten differences in almost identical images.
CB1100 – Can you tell the difference?
For 2017 the CB1100EX gets a gently re-sculpted tank, stainless steel spoked wheels rather than cast, led lighting incorporated into both the headlight and taillight, smaller and lighter mufflers, suspension improvements and a slipper clutch. Subtle but still an evolutionary improvement on a bike intended to evoke the gory days of 1970’s Japanese sport machines.
While there is thus far no indication that this pint size adventurist will be coming to Canada it does make for interesting news. No longer is the fan favourite, the V-Strom 650, the little bike and in fact that bike is huge in displacement compared to the 250. While sporting the ADV cues of its larger namesakes and powered by a small parallel twin, the V-Strom 250 (obviously they couldn’t go with P-Strom) is more about the ergonomics and comforts of the ADV class than it is about tackling the Dempster Highway and around town if should make for a admirable commuter with horsepower in the 25-ish range. Suddenly with the arrival of this Strom and the new GSX-R250 (which is coming to Canada), Suzuki has completely brought their small bike offerings into the modern world. Way to go Suzuki.
While having the handsome retro machine in the line-up that is the TU250, Suzuki was noticeably absent from the small displacement sport bike category that represents a large number of sales in the Canadian market. For a little history on that scenario: Kawasaki had the segment pretty much to themselves in Canada for many years with the Ninja 250 – an entry level bike with the stye and dimensions of its larger Ninja stablemates. The company sold a lot of them. Eventually Honda noticed and wanting to grab a few of those sales introduced the CBR250 which went on to do battle with the Ninja 250 to claim the title of best selling bike in Canada. With success comes even more competition and soon Yamaha and KTM had bikes in and around the segment as displacements rose to 300 and above. Suzuki has now thrown their helmet in the ring with a GSX250R. A clean take on the GSXR line-up the new bike has a 248 cc engine, 6-speed transmission and a wet weight of 392 lbs. Fuel economy is expected to be in the range of 76 mpg from a 4 gallon (US) tank. Oddly the Suzuki press release states that the new bike is inspired by not the GSX-Rs but of the popular Suzuki of the 1980’s and 90’s , the Katana. In the release the company says:
The GSX250R draws its design and performance inspiration from the legendary line of Suzuki Katana sportbikes. Resonating with Suzuki loyalists and motorcycle enthusiasts in general, Katana sportbikes stood for versatile real world performance, elegant design and practical ownership. The GSX250R will carry on that winning combination and easily position alongside Suzuki’s sport and standard motorcycle line-ups.
Kawasaki has dropped an adventure themed entry level bike into its Versys line with the reveal of the Versys 300X. While having some of the styling characteristics of the venerable KLR650 including the spoked wheels. the new 300X is not intended as an off-road machine but rather the new small Versys offers riders the benefits of ADV ergonomics including an upright seating position, a small windscreen and a broad seat with accompanying rear carrier platform. Also in the ADV mode the bike has a 19 inch from rim, a 17 inch rear rim, a 41mm Showa long travel front fork and hooks for strapping down luggage. The Versys 300X borrows power from the 296cc twin that is found in the Ninja 300 so this lightweight machine should easily have the get up and go to make highway riding comfortable. Small displacement touring should also be in the works as the 17l fuel tank should provide the new bike with an impressive range. The Canadian MSRP is at the moment TBD.
Recognizing that a 1198cc, 160hp engine might just be a little more than your average commuter might required, Ducati has introduced a smaller displacement machine in the Multistrada line. The Multistrada 950 is powered by a 937cc mill producing 113 hp and a peak 71 lb-ft of torque. Designed to be smaller all around and not just in displacement the new machine has a wet weight of just 500lbs. It comes with all the tech goodies including riding modes, power modes, ABS and traction control. If you want to dress your 950 up to further emulate the big bike there are various “theme” packs that will give the bike an adventure, touring or sport look.
BMW has dressed up their smallest bike in the company’s biggest of big boy pants with the introduction of the G310GS. The 313 cc machine gets the full GS appearance package – beaky nose, two tone paint, skid plate and rear carrier. The beefy little beast also includes niceties like a tubular steel frame with a bolt-on rear section, switchable ABS and an inverted front fork. 34hp and a low weight of 170 kgs should make this a kinder, gentler GS for those who do not want to wrestle one of the big boys through the forest and across the tundra. Now BMW doesn’t want anyone to think that just because the G310GS only has 25% of the displacement of the R1200GS it is not a real BMW. To that aim the company states:
A genuine BMW. Like the G 310 R, the G 310 GS represents everything that BMW stands for: progressiveness, outstanding quality and of course many years of carefree partnership with its owner. Excellent components and materials come together to make it a real all-rounder. The G 310 GS is the GS below 500 cc, providing worldwide entry to the premium world of BMW Motorrad.
The extent to which the G310GS will have a premium price tag has not yet been disclosed for the Canadian market. BMW now has a 700GS and 800GS and of course the company’s top two selling motorcycles, the R1200GS and the R1200GSA. The ADV market is the strong trending segment so it makes sense that BMW would want to provide both a stepping stone model and an entry level bike which the G310GS is both. Intesting the G310 turns up in the same year that Honda releases a big boy ADV version of the company’s CRF250L in the Rally version. Things are looking interesting in the play pen.
If you take away Harley, Victory and Indian – companies that only build cruisers (and an Empulse but is anyone, anywhere counting the Empulse?) – you are pretty hard pressed to find a ground up new cruiser being introduced to market. Not that many years ago the Japanese manufacturers were bountiful with cruisers but those offerings have been pared way, way down. One of Honda’s last great cruiser introductions was the Fury – an extreme style chopper with all the polish that comes with a Honda, a beautiful bike but unfortunately Honda jumped on the bandwagon just as the wagon wheels of the mainstream chopper trend went over the cliff. One could argue that the Valkyrie or F6B Honda introduced a few years ago would qualify as cruisers but in reality both are plays on the Gold Wing platform that may or may not extend that line’s staying power a few more years. Some claim that the shrunken state of the metric cruiser market is the result of demographics and cost. Cruisers at their peak were expensive, accessory and chrome laden machines that belonged to a better economic environment. To introduce the cruiser segment to a new, younger, less affluent breed of rider you have to give them a less expensive option. Give Honda credit for doing just that by resurrecting the Rebel name in the form of both a Honda Rebel 300 and a Rebel 500. Powered by a single and a parallel twin motor respectively the two Rebels bring a retro bobber vibe to the entry level market complete with solo seats, fat tires front and rear and a relatively low price. While Canadian prices for the bikes have not been announce the US price for the Honda Rebel 300 in non-ABS format is $4399 and the 500, $5999. If we had to guestimate the price of the 300 in Canada we would have go with about $5899 to take into account both the exchange rate and the fact that Honda is unlikely to bring the non-ABS bike into Canada. Let’s hope for the best on this new metric cruiser rebirth. Finally because nothing can lay on the accolades quite as thick as a press release let’s turn it over to Honda for a final description of the two machines:
Simple and raw, Honda’s new Rebel models are exercises in straightforward, minimalist design where every detail matters. Low, lean silhouettes are crowned by iconic fuel tanks, aggressively raked front ends and fat tires on large-diameter wheels, along with a stamped-steel rear fender and narrow frame body, resulting in stripped forms that express offbeat individuality from every angle. The evocative round, glass headlight sits up high in a die-cast aluminum mount, the speedometer is a compact dial with negative LCD display and blue backlight, and the ignition is housed below the left side of the fuel tank. Everything that can be is blacked out. With a 471cc parallel twin, the Rebel 500 has strong bottom-end torque and a smooth, linear power delivery, while the Rebel 300 is powered by a peppy 286cc single cylinder engine. In both cases, the bikes’ riding positions are relaxed and neutral, with arms gently outstretched and feet dropping straight down to the mid-mounted pegs. The versatile Rebels are fun to ride slow and fast, great for day trips, jaunts to the coffee shops or even sporty sessions on winding roads; low weights, slim frames and short seat heights equal agility at lower speeds, whereas good ground clearances allow surprisingly sporty lean angles.
The little Suzuki V-Strom 650 gets updated for 2017 with the intention of re-uniting the family resemblance between the big and little v-twin adventure bikes. The 650 now gets the stacked headlights and beaky nose of its larger sibling. But the changes are not all cosmetic. The 650 also gets a traction control system, an easy start mechanism and low rpm assist. While traction control seems self-explanatory, the other two features may not be. Easy start means only having to push the start button once and not hold it down until the motor engages. Low RPM assist will help prevent stalls in slow speed maneuvering which should be beneficial should you take the little ‘Strom rock crawling. The 650 version of Suzuki’s adventure twins has always held a special place in many riders hearts and is often in favoured over its larger stablemate. Having the two bikes present a unified face should benefit both machines. The bike will be offered in two forms: the standard edition with cast wheels and the XT edition with spoked wheels and a few protective pieces.
Not wanting to exhaust all the excitement at the Intermot show in Germany Kawasaki announced that the company will announce the arrival of the Z900 and Z650 at the EICMA show in November. The naked Z family is growing with the recent news of the Z125’s arrival in Canada. Where the new 900 and 650 fit into the current 125, 800 and 1000 line-up remains to be seen as it appears to be getting very crowded near the top. It may well work out that due to different licensing requirements in different countries around the world that the 650 and 900 may not be available in all markets. We await the remaining announcement of the announcement for more details.
Do you long for the days when each and every year it seemed as though a few grams were shaved off your favourite sportbike? A lighter muffler here, a couple of shorter bolts there, a few strategic carbon fibre bits all over. If it all added up to a few pounds it was big news, a major selling point that really had nothing to do with the real world. But it gave a few guys bragging rights. Add that to colour schemes that looked like a clown threw up his last meal of neon crayolas …. ahhhh, those where the days. For the past few years however the focus has been on big power and conservative paint – two items that probably should go together. Honda has just bucked part of that trend as weight loss has taken centre stage with the new 2017 CBR1000RR SP. This svelte new model comes in at a whopping 15 kgs lighter than last year’s SP which no-one would have called portly. And another 10 hp just to make things a little more interesting. As with most Honda products – with the possible exception of the monkey bikes – the new CBR is all about getting the job done without an excess of flash – because ultimately engineering does trump flash.
For the engineering nitty gritty, let’s turn it over to Honda: CBR1000RR SP – Next Stage Total Control
Three factors are key to the essence of the new CBR1000RR SP; less weight, more power and electronics to help the rider wherever and however they’re riding.
The new electronic control system provides constant, selectable and fine-tunable rider support. Central to the system is the 5-axis Inertial Measurement Unit (IMU), which measures exactly what the machine is doing, in every plane. It works the Honda Selectable Torque Control (HSTC) that precisely manages rear wheel traction via the FI-ECU and Throttle By Wire (TBW). The new ABS (also managed by the IMU) offers Rear Lift Control (RLC) and the ability for hard, safe trail braking into corners. Any difference measured between the front and rear wheel speeds engages Wheelie Control, depending on settings.
It also works with the Öhlins Objective Based Tuning Interface to adjust both the compression and rebound damping force of the semi-active Öhlins Electronic Control (S-EC) front fork and rear shock. For the rider this means access to a whole new level of handling ability, with suspension reaction—whether working through pre-sets 2017 CBR1000RR SP or manual input—that delivers exactly the right amount of control in every situation. It functions as well on the road as it does the track, and for Honda a new era begins.
At the same time as the S-EC is working the suspension, the Honda Selectable Torque Control (HSTC) is precisely managing rear wheel traction through the IMU, FI-ECU and Throttle By Wire (TBW). It also delivers a Wheelie Control function. Three standard display modes—Street, Circuit and Mechanic—provide all the information required for the rider relevant to the type of riding. The information displayed can be fine-tuned and adjusted while riding by using the left-hand switch gear and TFT liquid crystal display, just as on the RC213V-S, Honda’s road going version of its RC213V MotoGP machine.
While the electronic control is very much a new departure for the CBR1000RR SP, the combination of the other two factors draws faithfully on the philosophy of the original 1992 machine: the optimal balance of power and weight. The engine revs harder and higher, with a much higher compression ratio and revised cam timing, and uses the TBW (a first for an inline four-cylinder Honda) and Acceleration Position Sensor (APS) which have been inspired by the technology developed for the RC213V-S.
Bottom-end torque and power are improved, with a significant increase in top-end power—up 10 hp—and 3 modes of engine output character can be chosen from. A Quickshifter is fitted as standard, as is Downshift Assist (with auto-blipper) and new assist slipper clutch.
Thanks to the use of magnesium and careful assessment and lightening of individual parts, the engine also carries 4.4 lbs. less. The new titanium exhaust muffler saves further weight and aids mass centralization, as does the titanium petrol tank. Overall the CBR1000RR SP is 33 lbs. lighter than the outgoing model.
The twin-spar aluminum frame’s rigidity balance has been finely adjusted, and the swingarm is stiffer to match. A new rear subframe is lighter as are the redesigned wheels, while Brembo monobloc four-piston front brake calipers use highperformance track-ready brake pads.
The CBR1000RR SP ’s bodywork outlines an aggressive, functional minimalism, and the machine is slimmer and much more compact with a single seat unit fitted as standard. All lighting is LED and the stunning Tri-Color paintwork—on a red base— harks back to Honda racing history.
3.1 Chassis/Electronics • Inertial Measurement Unit (IMU) • Öhlins Electronic Control (S-EC) suspension • Honda Selectable Torque Control (HSTC) • New ABS • Riding Mode Select System (RMSS)
The CBR1000RR SP is the first Honda motorcycle to be equipped with Öhlins S-EC suspension front and rear: a 43mm NIX 30 fork and TTX 36 shock. 2017 CBR1000RR SP
The Suspension Control Unit (SCU) receives roll rate, yaw rate and lean angle information from a 40g 5-axis (3-axis acceleration and 2-axis angular velocity) Bosch MM5.10 IMU gyro located close to the machine’s center of gravity. It also gathers wheel speed, engine rpm, brake input and throttle angle from the FI-ECU and, depending on the suspension mode selected by the rider delivers optimal compression and damping force (adjusted via each step motor) during normal riding, plus hard acceleration, braking and cornering.
There are three Active modes and three Manual modes for the rider to choose from. When set in Active, damping force is controlled and optimized to suit the riding conditions: A1 (“Fast”), A2 (“Enjoy”) and A3 (“Safety”). Within the Active Modes the rider can make finer adjustments. The Manual M1, M2 and M3 Modes allow any required adjustments to be made.
Within the electronic control system are a multitude of active features that many riders will find useful. The new ABS allows extremely hard braking while maintaining rear wheel contact with the ground, stopping the tendency for the rear of the machine to elevate or “back in” around the front. It uses the 2-axis acceleration information from the IMU and calculates the acceleration of the machine’s center of gravity in the lift direction and acceleration perpendicular to that, using the front wheel as a grounding point.
ABS delivers smooth, effective braking into a corner. With information from the IMU, plus front and rear wheel speed sensors, the ABS Modulator controls braking force according to lean angle, even when panic braking. But it also allows for hard trail braking by using two parameters (deceleration derived from wheel speed and front/rear slip rates) plus lean angle to vary the threshold for ABS decompression. ABS delivers an extra sense of security when braking hard on the road, and offers a performance edge in certain conditions on the racetrack.
In isolation all the functions of the EBC—plus the HSTC’s wheelie control—perform specific, individual tasks. When tied together, however and working seamlessly as one they provide technological rider support that elevates the super sports experience, without turning the rider into the passenger. Next Stage Total Control, indeed.
Like the RC213V-S, the CBR1000RR SP uses a full-color TFT liquid crystal dash that clearly communicates information to the rider. It automatically adjusts to ambient light, with a backlight of up to 1000 cd/m2 luminescence and features 3 modes; Street, Circuit and Mechanic, each displaying information most relevant for usage.
Street displays riding modes (1-3 and USER 1-2) plus the settings for each parameter P (Power), T (HSTC), EB (Selectable Engine Brake) and S (Suspension). Circuit adds in addition to Street mode the lap time, number of laps and difference from the best lap. Mechanic displays the digital tachometer, gear position, grip angle, coolant temperature and battery voltage.
Riding mode 1 (FAST) gives full power, with linear throttle response, low HSTC and EB intervention and high damping force. Mode 2 (FUN) controls output through first to third gear, with fairly moderate power increase, medium HSTC, strong EB and medium damping force. Mode 3 (SAFE) controls output through first to fourth gear, with moderate power increase, high HSTC, strong EB and low damping force. 2017 CBR1000RR SP
In the 2 USER modes all parameters can be combined and adjusted freely; riding modes, HSTC and suspension settings can be changed while riding from the up/down switch on the left switchgear.
The Shift-Up indicator is a horizontal line of 5 white LEDs located at the top; when engine speeds exceed user presets they go from solid to flashing. Displays include speedometer, tachometer, gear position, quickshifter, coolant temperature, riding distance and twin trip meters.
The onboard computer calculates instantaneous and average fuel economy, trip fuel consumption, average speed and time after last ignition plus remaining fuel after RES light and distance to empty (when selected). This information is shown on the bottom right of the screen. In the upper display, middle right the rider can choose to see the Shift-Up indicator setting speed, grip angle, battery voltage, calendar, or user-defined text.
Switching between modes is controlled by a mode switch on the right of the left-hand switchgear. Just above it is an up/down switch that manages and changes the information displayed within the mode.
3.2 Chassis • Adjusted rigidity balance for the frame • Stiffer swingarm • Lighter subframe • Titanium fuel tank • Brembo four-piston radial mount monobloc brake calipers • Redesigned wheels • Minimal and aggressively styled bodywork
As a machine now a full 33 lbs. lighter and with a 10 horsepower power boost, the CBR1000RR SP’s physical handling has also been transformed. Rake and trail remain 23° 3’/96mm but the hollow die-cast twin-spar aluminum frame’s rigidity balance has been significantly adjusted to give even sweeter handling with outstanding steering response, feel and stability.
Thinned frame walls save 300 grams. While transverse rigidity is unchanged, the frame is 10% more flexible in the torsional plane, which works to deliver a fasterreacting chassis. Yaw moment of inertia has been reduced by 15%; roll moment of inertia by 10%. The Honda Electronic Steering Damper (HESD) unobtrusively maintains stability. To complement the frame changes the aluminum Unit Pro-Link® swingarm’s hybrid structure has had the thickness of each section adjusted, saving approximately 100 grams while maintaining transverse rigidity and increasing torsional rigidity.
The die-cast aluminum subframe too has been redesigned and its thinner construction is at the same time highly rigid and 800 grams lighter—contributing to the concentration of mass and thus neutral handling feel with improved agility. Wheelbase is 55.3 in.; seat height is 32.3 in.
Positioned high, the weight of the fuel tank (and fuel) plays a significant part in a motorcycle’s handling. In another first for mass production, Honda has developed a compact 4.23 gal. titanium fuel tank for the CBR1000RR SP. Manufactured by an ultra-deep drawing process, it’s 2.86 lbs. lighter than an equivalent steel design and contributes to the concentration of mass and reduction in the moment of inertia. 2017 CBR1000RR SP
Brembo four-piston monobloc radial mount brake calipers use newly developed highmu (coefficient of friction) brake pads—these have a greater performance parameter at higher temperatures than standard pads, and suit aggressive riding. The aluminum wheels are a new five Y-shape spoke design, saving approximately 100 grams. Tire sizes are 120/70 R17 front and 190/50 R17 rear.
Minimal and dynamic are two words used to best describe the CBR1000RR SP ’s new styling. The design team wanted to create tightly compact proportions and the upper and middle fairing surfaces have been reduced in size as far as possible. Forward tilting character lines inject an aggressive attitude, with a focus on mechanical functionality, detail and quality of finish.
24mm in width has been squeezed from the upper fairing. Airflow control from the flow surfaces of the fairing, to the surface angle of the headlights and the contouring of their side slits supports stability at speed. In a racing crouch the rider is tucked well out of the airstream. In normal riding situations air pressure is evenly distributed on the rider’s shoulders, back and sides.
18mm has been saved across the middle fairing and its “knuckles” double as RAD intake structures that pass discharged air around the outside, and underneath, the rider’s legs. The knee grip area is 15mm per side slimmer, with the interface between tank cover and the single seat unit athletically accentuated.
All lighting is crisp LED, with the twin front headlights offering high/low beam on both sides. Crowned with a sharply angled new logo, the CBR1000RR SP will be available in a Tri-Color paint option that uses red as its base (rather than white) and pays homage to Honda’s racing tradition and history. Wing-motif patterns underpin the machine’s exclusivity.
A 2.2 lb. Lithium-Ion battery saves weight (a lead-acid unit of similar output would weigh 4.4 lbs.) and provides reliable and consistent electrical charge.
3.3 Engine/Electronics • Throttle By Wire (TBW) • Acceleration Position Sensor (APS) • Power Selector • Inertial Measurement Unit (IMU) • 9 level Honda Selectable Torque Control (HSTC) • Wheelie Control • Selectable Engine Brake (SEB) • Quickshifter • Downshift Assist • Riding Mode Select System (RMSS)
The 2017 CBR1000RR SP is the first inline four-cylinder engine from Honda to use Throttle by Wire (TBW) control. Derived and developed from the system used by the RC213V-S, its job is to put precise throttle control—and a very natural feel—in the rider’s right hand.
Heart of the system is a newly developed throttle grip Acceleration Position Sensor (APS) integrated into the right handlebar switchgear, which itself neatly mounts the engine start/stop switch—nothing more. APS converts movement of the grip into an electrical signal sent to the ECU, that then transmits it as an actuator signal to the TBW motor, achieving ideal throttle control relative to grip angle.
The return spring and other mechanisms inside the APS reproduce the initial play and natural feel of a cable, with throttle load set specifically for the CBR1000RR SP. Working in conjunction with the APS, throttle bore is increased 2mm to 48mm (without increasing exterior width) and careful shaping of the intake funnels adds to the linear throttle response.
The Power Selector can be accessed through the Riding Mode Select System (RMSS). It offers 5 levels of output character: Level 1 give peak output in all six gears; Level 2 output is controlled in each gear to achieve smooth throttle feel under acceleration or deceleration; Level 5 has the strongest output control for most moderate throttle response. All levels have the same throttle response on initial opening.
Riding Mode (1) uses Level 1 as its preset, drawing out the full performance of the engine. Mode (2) uses Level 2, and is suitable for twisty roads, while Mode (3) goes to Level 5 for maximum security. Individual rider preferences can also be input manually through the USER 1 and 2 interface.
The CBR1000RR SP employs an enhanced version of the Honda Selectable Torque Control (HSTC) used on the RC213V-S. It controls engine torque via two sensing methods—the first uses wheel-speed sensors to measure and compare front and rear wheel speeds. When the FI-ECU detects rear wheel acceleration (and front wheel deceleration) it reduces the TBW throttle position, and thus output, keeping the front wheel on the ground. Maximum application of the throttle is thus possible without fear of wheelies, with the support of Wheelie Control.
The second sensing function detects machine roll angle. The IMU located under the seat detects rotational speed in the chassis’ roll and yaw directions, and acceleration in the longitudinal, lateral and vertical directions. It then calculates roll angle to 2017 control engine torque, maintaining rear wheel traction at the required level. The body roll calculation logic used by the ECU uses the same attitude detection technologies developed for Honda’s ASIMO humanoid robot, enabling the most precise calculation possible.
Nine intervention levels (plus off) are offered by HSTC to suit rider preferences, and the Riding Modes USER 1 and 2 enable individual changes to be made while moving.
There is also a Selectable Engine Brake (SEB) system to change engine-braking character to match rider preference and a range of conditions. Level 1 offers the highest braking force, Level 3 the lowest. The preset Modes 1, 2 and 3 use recommended settings, but through USER 1 and 2 can be set individually.
A Quickshifter is fitted as standard for clutchless upshifts and works through fuel injection cut and ignition retard. It has 3 settings plus off. Downshift Assist allows clutchless downshifts, and also works via fuel injection cut and ignition retard with TBW autoblipping. It too has 3 settings plus off.
3.4 Engine • 10 hp increase • Revised valve lift and cam timing • Magnesium covers and detail redesign saves 4.4 lbs. • 4-2-1 exhaust with titanium muffler • Redesigned downshift assist • New assist slipper clutch
Honda’s engineers exhaustively re-examined the CBR1000RR SP’s 999.8cc inline four-cylinder engine to make it as light and powerful as possible. The result of the work is an extra 10 hp, the loss of 4.4 lbs. and raised rev ceiling of 13,000 rpm.
Bore and stroke remain 76 x 55.1mm but compression ratio is up from 12.3:1 to 13:1. This is an engine in a very high state of tune and the crankshaft, valve train and transmission all use higher specification materials than the previous design.
The pistons feature an optimized wall thickness and a new crown design to raise the compression; the surface finishing of the piston-ring grooves has also been modified to improve sealing performance and efficiency. Valve lift and cam timing has been revised to match the higher rpm and greater engine performance.
Power up is just one part of the CBR1000RR SP ’s story—reduced weight is another. So every part of the engine was scrutinized to see if it could be made lighter. All the engine covers are redesigned (clutch cover is aluminum; the ignition cover magnesium) and the length of the bolts, water hose and water hose bands have been reduced.
With a revised, rounded shape the radiator is 30mm narrower in overall width and 100g lighter (including a 30cc reduction in water capacity). Using a new high-density core it achieves identical heat dissipation and contributes to the slimmer frontal area of the fairing cowls.
The assist slipper clutch is completely revised with a single die-cast pressure plate and clutch center, and offers reduced load at the lever. For downshifts the slipper functionality remains the same as before but aluminum cam parts (instead of steel) save weight. The gap between the accelerating and decelerating cams has also been optimized, again improving lever feel when changing gear. All of the transmission gears have been pared down to save weight.
The titanium irregular cross-section muffler is 6.17 lbs. lighter and minimizes the center of gravity change; it also creates an unmistakable sound tone from the exhaust on an open throttle. The exhaust supplier to the Repsol Honda MotoGP team was asked to develop the prototype and produced an exquisite design with the 4-2-1 double-skinned downpipes incorporating the exhaust valve within the first main pipe.
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