First Ride of Yamaha Mt09
7 mins read

First Ride of Yamaha Mt09

When you have a good thing going, you don’t change it unnecessarily. Yamaha Motor Corporation, USA has sold 24,000 MT-09s between its introduction in 2014 as the FZ-09 and the end of 2020. In the modern motorcycle world, where some iconic models move under 1,000 units a year in the US market, that makes the 09 a mammoth hit. Sure enough, it’s one of Yamaha’s more popular models, selling well and continually. Yamaha USA Product Planner Aaron Bast attributes the MT-09′s previous success to its three strengths: torque, agility, and value. Especially value; the original 2014 model sold, an awesome price then; six years after, it has only climbed. Bast also says the whole point of the new version is to offer more: more torque, more agility, more value.

So the 2021 MT-09 is much more than an update, even if it’s just slightly less than an absolutely complete redesign. Its three-cylinder engine is obviously based on the original 847cc powerplant, but has more new parts than old. Yamaha, as all other manufacturers, has to meet stringent Euro emission rules with the new bike, even though they want to increase performance. Lower emissions have traditionally meant less power, so the engineers gave the bike a new crankshaft with a 3mm-longer stroke, taking the displacement up to 890cc. Additionally, the new crank has 15 percent more inertia, slowing engine response slightly while increasing the engine’s perceived smoothness. To keep deck height the same even with the longer stroke, the connecting rods are 1.5mm shorter. New forged pistons with concave tops maintain the 11.5:1 compression ratio of the outgoing 847cc engine.

A new cylinder head was created for both emissions and performance. It was given 12 percent less coolant volume for faster engine warm-up; most hydrocarbon emissions are created while an engine is still warming, while the fuel mixture must be rich and the exhaust catalyst isn’t yet up to temperature. For better performance, the new cooling passages completely encircle each exhaust valve seat, eliminating the potential hot spot between the valves. Intake ports were redesigned with reduced volume for faster flow, and the injectors were repositioned and re-aimed to hit the backs of the intake valve. All these changes lead to better fuel vaporization and mixing, improving both emissions and drivability. New camshafts have reduced timing, with 30 percent less overlap; there is now only a 20-degree period during which both intake and exhaust valves are open simultaneously. Shorter timing and less overlap generally favor emissions and torque over top-end performance, but the engineers gave the cams notably steeper ramps, so the curtain area under the whole lift curve stays relatively high. The new ramps are so steep that the entire cam drive had to be redesigned with a wider and stronger cam chain and an oil-pressure-powered cam-chain tensioner added. The tensioner provides more tension when the engine is spinning fast, when the cam chain is more likely to whip around, and less drag at lower rpm.

The intake and exhaust systems also were retuned and redesigned. Three unequal-length runners poke up into the airbox, a design that delivers more torque, a smoother powerband, and a delightful intake note. The exhaust system is pieced together from stainless steel stampings with beautiful robotic welds that look as good as those on some high-end race pipes. It’s an all-new design that places the catalyst forward in the conical header portion of the pipe for quicker warming (emissions again) and tucks almost all the muffler under the engine for better mass centralization. The increased displacement and new engine tuning is claimed to increase torque by 6 percent while further broadening the band. Fuel economy is said to be 11 percent better than with the previous model.

Other details were seen to as well. A double-acting, ramp-style slipper clutch, similar to the one in the YZF-R1, releases on back torque and tightens on acceleration, allowing substantially lighter springs and reduced clutch effort. First and second gear ratios were raised by about 3 percent, because of the increased torque and crank inertia. The engine and exhaust system in combination is 3.8 pounds lighter than that of the 2020 model.

While the engine can be considered an update, the ’21 MT’s frame is all new. It follows the brilliant pattern of the previous bike with a construction nearly unique in motorcycling. There are no welds in the MT-09 frame. It comprises two frame halves made from a super-high-vacuum, high-pressure die-casting process that produces higher-strength parts than typical HP die-casting. (Ducati has used the same process for Panigale V-twin crankcases.) The parts come from the dies fully formed, needing only a facing operation before they can be bolted together permanently with tamper-proof fasteners. Then the steering-head bores are machined for bearings, and the frame is done. The three-cylinder motor, when it’s bolted in, reinforces the structure. Beautiful and inexpensive, the frame has always been one of the reasons that Yamaha can offer the MT-09 at an attractive price. This year the construction remains the same, but all the details have changed. The steering-head tube is lowered by 30mm, reducing bending leverage from the fork and allowing a straighter side beam layout. Yamaha claims the afteral stiffness is improved by 50 percent.

The swingarm used to be constructed similarly, in two halves, but the new one is a welded box-section design that’s 0.6 pound lighter. But the two-piece bolt-together die-cast aluminum construction now makes its way to the subframe, replacing what was previously a welded steel part and achieving a 3.3-pound weight reduction. Wheels are also lighter, with the rim section of the cast wheels spin-formed with heat and rollers after casting to improve material strength, allowing a thinner section there. The wheels have 11 percent less rotary inertia, a change that lightens steering and improves acceleration.

Along with chassis and engine changes, the new 09 gains an impressive array of new electronic riding aids that Yamaha says were directly derived from those of the R1 superbike. A new six-axis IMU (Inertial Measurement Unit) tracks exactly what the bike is doing in 3-D space, allowing very sophisticated traction control, lift control (anti-wheelie), and slide control systems to be implemented by the 09′s ECU. This is helped by a new electronic ride-by-wire throttle system that allows the control system to work at multiple levels: spark, fuel, and throttle, depending on the exact need. A new full-color TFT display and dedicated handlebar buttons allow the rider to select from four different throttle maps and three different levels of each of the other control systems, with the additional option of disabling any one or all of them altogether. The IMU also feeds data to the ABS system, allowing it to be mapped to respond appropriately to rider lean. Before starting a ride, you can select either this mapping or a conventional ABS map that ignores the IMU; but unlike the other rider aids, you can’t switch the ABS off. Yamaha also included a quick-shifting system with a shift sensor that allows clutchless up- or downshifts, and allows the rider to turn the system off if desired.

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