MT-09: Details behind its development

MT-09: Details behind its development

“This engine is excellent, it pulls superbly, already at low and mid revs” says test rider Jeffry de Vries. “The throttle response is so immediate and direct, and you feel you have a lot of power, always. It’s a treat to ride it. There are some characteristic vibrations and they are nice too. Instead of being annoying, they give a certain character to the bike. It’s a new experience.”

2014_MT09_Sport Touring_Engine CAD from 236-538945 (gc_single_col)Engine CAD
2014_MT09_Sport Touring_Engine with offset cylinders from 236-538951 (gc_single_col)Engine with offset cylinders
2014_MT09_Sport Touring_Injection precision from 236-538981 (gc_single_col)Injection precision
2014_MT09_Sport Touring_Intake funnels with uneven lengths from 236-538987 (gc_single_col)Intake funnels with uneven lengths
2014_MT09_Sport Touring_Sound from 236-538993 (gc_single_col)Sound

In fact, this modern and fuel-efficient engine incorporates the latest racing technologies. They combine power and precision with light weight.
Its DOHC engine design features downdraft intakes, forged pistons, plated cylinders and fracture-split connecting rods.
 “We were able to make this engine 10 kilo’s lighter than the 4-cylinder FZ-8 engine” states Project Leader Akira Kimori.
Offset cylinders
The cylinders are offset by 5mm from the centre of the crankshaft to reduce friction losses: a recent Yamaha technology already applied in the YZ450F motocrosser.
By offsetting the cylinders, the conrod position is more straight under the piston at the moment of greatest combustion force and the piston is not pushed into the cylinder wall so strongly. This also improves fuel efficiency.
Injection precision
The fuel injection uses 12-hole injectors that are attached directly to the cylinder head for precise and efficient injection directly at the valve skirt. At the same time, this position enables a shortening of the throttle body, for better performance in the high rpm range.
Yamaha’s fly-by-wire throttle (YCC-T) ensures an exciting and direct throttle response which can be adjusted by the D-mode system in three different settings.
Quicker warm-up
Even the water cooling route is kind of unique: our engineers developed a layout with short hoses and a thermostat located before the water pump, resulting in light weight and quicker warm-up (which even helps for fuel efficiency and emissions too).
Also remarkable on this engine are the intake funnels that contribute to the excellent intake sound. They have been designed with uneven lengths. The first cylinder funnel is 102.8 mm, the second 82.8 mm and the third is 122.8 mm so that the power and torque curves produced by each intake, complement one another positively. This results in excellent torque characteristics in the middle rpm range and up. And it also helps to give a pleasing, fine-tuned intake sound.   

2014_MT09_Sport Touring_Combustion torque and Inertial torque from 236-539036 (gc_single_col)Combustion torque and Inertial torque add up to Composite torque
2014_MT09_Sport Touring_In a normal in-line 4-cylinder, two pistons always rise and fall at the same time from 236-538975 (gc_single_col)In a normal in-line 4-cylinder, two pistons always rise and fall at the same time
2014_MT09_Sport Touring_In a crossplane engine, pistons are 90 degrees apart from 236-538969 (gc_single_col)In a crossplane engine, pistons are 90 degrees apart
2014_MT09_Sport Touring_In a 3-cylinder engine, pistons rise and fall 120 degrees apart from 236-538963 (gc_single_col)In a 3-cylinder engine, pistons rise and fall 120 degrees apart

Clean torque
Inside an engine there are two main forces creating the final pulling force at the drive axle.
The first one is the combustion torque: created by the explosion in the cylinder.
The second force is the inertial torque: created by the rotating mass of the crank and the mass of the pistons moving up and down.  
Especially the inertia created by the pistons that have to stop and reverse their motion at the top dead center and top bottom center of the piston stroke, interfere strongly with the combustion torque (as you can see in the graph).

In a normal in-line 4-cylinder engine, two pistons always rise and fall at the same time, and the four pistons are all at the same time in a dead point (two in top dead center and two in bottom dead center), which creates high forces that work against the combustion torque.

Yamaha already developed the famous 4-cylinder ‘crossplane engine’, in the M1 race bike and the R1 supersports, to harmonize the interference of combustion and inertia torque. We call it “clean torque”.
In the 3-cylinder engine, there is a similar clean torque effect. The pistons rise and fall 120 degrees apart so they are never in a dead point at the same time and the inertial torque is much less and also less interfering than with a normal in-line 4-cylinder. So both the crossplane P4 and the P3 engine have the clean torque delivery which is in line with Yamaha’s philosophy to create a unique interaction between rider and machine.
The result is that the rider can feel a more direct connection to the combustion torque. In short, better control of engine power, resulting directly in more excitement!

2014_MT09_Sport Touring_Aluminium frame and beefy rear arm from 236-539029 (gc_single_col)Aluminium frame and beefy rear arm
2014_MT09_Sport Touring_Tapered handlebar from 236-539017 (gc_single_col)Tapered handlebar
2014_MT09_Sport Touring_Super agile from 236-539053 (gc_single_col)Super agile
2014_MT09_Sport Touring_Narrow knee grip from 236-539011 (gc_single_col)Narrow knee grip
2014_MT09_Sport Touring_MT-09 Sketch from 236-539005 (gc_single_col)MT-09 Sketch
2014_MT09_Sport Touring_Forward mass and Flexible riding position from 236-538957 (gc_single_col)Forward mass and Flexible riding position
2014_MT09_Sport Touring_Emotional ride from 236-539023 (gc_single_col)Emotional ride

Serious bike
“We did not want to make just another allround midclass bike” says Oliver Grill of Product Planning. “The MT-09 should be a high capability bike, built for serious riding performance.”
The chassis components on the bike are a clear example of that thinking.

  • The aluminum frame and beefy aluminum rear arm are constructed by Yamaha’s CF diecast production method for the lightest weight possible.
  • The handlebar is a tapered aluminum one for the same reason.
  • The triple crowns are both in full aluminum, even the bolt on top.
  • Both wheels are beautiful and light, 10-spoke cast aluminum designs.
  • Brake and shift pedals and footrests are forged aluminum for optimal strength.

Go faster at slower speeds
“We used the phrase that you should go faster at slower speeds. Because nowadays there are not many places where you can go with high speeds anymore.”
For that aim, the weight reduction on this bike is extreme: 23 kg less than an FZ-8!
Project leader Akira Kimori adds: “Our test riders spent lot of time to find the best riding position, supported by a good heel guard design and shape of the fuel tank, to have a good fit with the bike. That is linked to our concept, to have ultimate controllability. We also spent a lot of time for suspension and geometry setting, to make the bike super agile.”
This way, the whole chassis is tuned for agility:
  • The knee grip is very narrow thanks to the narrow engine and strongly sculpted indent in the fuel tank.
  • Also the lower leg area is kept narrow, due to a special swingarm attachment at the outside of the frame the foot grip is as slim as on a parallel twin.
  • The whole bike is compact with a close connection to the rider.
  • The upright riding position and straight handlebar give an active stance.
  • The front brakes are supersport-spec with two floating 298 mm discs and radial mounted, monocoque 4-pot calipers: for precise and powerful braking.
  • The seat has a relatively flat top to move around and shift your weight easily.
  • The suspensions have relatively long stroke and excellent shock absorption capabilities.
    The 41mm, USD front fork can be adjusted for preload and for rebound damping.
    The rear shock has a progressive linkage and can be adjusted for preload and for rebound damping.
  • Even the oil pan is special, with a shape that provides little fluctuation in the oil surface even during sudden machine movements and enables a deep banking angle of 51 degrees - similar to that of a supersport machines.   

“The riding position is very active” says Jeffry. “You sit very close up front of the bike, with a wide handlebar, and the bike itself feels very light. So you feel like you are in full control.”
Akira concludes: “We built the MT-09 for an emotional ride. It is a super agile roadster with ultra controllable handling that can bring a lot of excitement. But it is not fragile or exclusive, you can easily enjoy it every day. That is our Yamaha direction for the future.” 

Technical specifications

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