The American Motorcyclist Association
URL for this article: www.amadirectlink.com/riding/reviews/2009/vmax/index.asp
Irrational exuberance: Star Motorcycle's redesigned Vmax redefines muscle-bike genre
Posted August 22, 2008
By James Holter, photos by Nelson/Riles
How do you evaluate a motorcycle whose most notable feature is a number? One-hundred-and-ninety-seven horsepower. To a rational mind, it's boggling, functionally irrelevant, over-the-top ridiculous.
For many motorcyclists, these adjectives represent excess. For the Vmax buyer and many would-be Vmax buyers who will miss out on the 2,500 allotted to the United States for the 2009 model year this excess is the Holy Grail. Everything else is just the box used to package the hyperbole.
Not that it's a bad box. Ridden at the North American press introduction in San Diego, the $17,990 Vmax comes across as refined, well-designed and, with some caveats, engineered much like a machine built for the real world, where urban commutes and backroad twisties are the norm. Take a peek inside the packaging, however, at the insane power inside, and you quickly realize the Vmax is like few production motorcycles ever built.
After all, how many production bikes have a third gear that can handle a single digit or three? Yes, the torque curve is that fat, the power spread that wide.
Much of the reason the Vmax is in limited company is not many motorcycles have tried to join the party. The Vmax is the original muscle bike, the power cruiser, the motorcycle version of big, powerful American cars from the 1960s and '70s Cameros, Novas, Mustangs, Chargers. For years, the Vmax stood alone. Today, however, it's joined by machines such as Harley-Davidson's V-Rod, the Suzuki B King, and other models designed with the seemingly singular goal of horsepower at all costs. The competition has forced Yamaha, doing so under the Star Motorcycles badge, to redesign the original after 23 years of minor updates.
The motor's the thing
At the heart of that redesign is the incredible V-4 engine. The 1,679cc powerplant boasts four massive 48mm valve bodies, each with a 12-hole Mikuni injector spraying into the combustion chamber.
The four valves for each cylinder are operated by dual camshafts, the exhaust gear-driven off the intake, which is rotated by the cam chain. This design, as opposed to the common approach of two
chain-driven cams, allows the camshafts to be much closer together, resulting in a 27mm shorter head than the original V-4 engine and plays a large part in the 7mm reduction in the overall length,
despite the cubic centimeters increasing by nearly 500cc.
Yamaha says its marketing research shows that Vmax riders don't just want acceleration. They want acceleration with character. The power delivery needs to have a "wow!" factor.
In the first generation of the Vmax, the wow was provided by the V-Boost, a mechanical butterfly valve that opened inside a tract connecting two of the four cylinders. It allowed one cylinder to be fed by two carburetors on an intake stroke within a certain rpm range.
The Vboost returns in the new, fuel-injected Vmax, but in spirit only. The mid-range surge in power is handled by the CPU, which receives constant input from engine sensors, environment sensors, wheel sensors and the fly-by-wire throttle. The same smarts allow the bike to perform such feats as greatly reducing off-idle bog (sensors recognize a too-quick throttle opening and restrict fuel just enough to front-run the effect) and, along with the slipper clutch, controlling engine braking (minor amounts of fuel are metered out when the throttle is chopped).
The Vmax's iconic air scoops, however, are back in a big way as in, this time they are functional. The dual intake system boasts 13 liters of airbox volume, fed by the two huge scoops. The Vmax
features Yamaha's Chip Controlled Intake system, also used on the R1. This creates a positive intake pulse effect by varying the intake funnel length. Tall intake funnels optimize low-to-mid rpm
acceleration, while short intake funnels optimize high-rpm acceleration.
There's a lot going on with the four-into-one-into-two-into-four exhaust, but the design and the thoughtful placement of the openings, pointed upward and roughly in line with the operator's head, results in an inspiring gutsy roar that benefits from an efficiently aimed shot from exhaust to eardrum.
A ramp-type slipper clutch offers more control under braking, as well as smoother downshifts. Hydraulically actuated, the clutch uses 10 friction plates vs. the eight employed in other models that use the same size basket. Pull is not the lightest on the showroom floor, but it isn't onerous, either. Power is transferred to the beefed-up shaft drive through a five-speed transmission.
The whole thing is kept cool by an industrial-looking dual radiator, one mounted above the other. The upper portion is curved while a fan is mounted to the lower section.
The result of all that tech is a motor with more character than a Pixar animated film. Things wonderful, powerful things happen when you turn the throttle on the '09 Vmax. The motorcycle, suffice it to say, moves forward quickly. Just as important, the Vmax has personality. It might hit like a boxing heavyweight, but it showboats like the World Wrestling Entertainment star of the week.
The challenge is keeping the power, as well as the lively delivery of that power, controllable and, to be frank here, safe for the average rider. No, the Vmax is not a beginner's motorcycle, but you don't need the throttle control of a pro flat-tracker to keep the wheels in line. Sensibility and restraint can tame the Vmax's 197 ponies.
A better box
A big part of the controllability equation is the chassis.
The new Vmax has a twin-spar cast aluminum main frame that uses the engine as a stressed member. Extruded aluminum is used in the subframe. The goals are light weight, rigidity and precise handling.
The swingarm is also aluminum. Although Yamaha reps admit that a dual-shock design was once potentially in the cards as a throwback to the original, the new version goes with single-shock design. A Yamaha SOQI shock is used, with adjustable preload, compression and rebound, and offers 4.3 inches of travel.
The front uses a monster-sized 52mm SOQI fork, titanium oxide coated for a very trick glossy black finish on the upper fork tubes. The aluminum triple clamps (cast top, forged bottom) are offset by 30mm.

The braking duties are handled by Brembo master cylinders. The front uses six-piston Sumitomo calipers to clamp the two 320mm wave-type discs. The rear feeds an Akebono caliper mated to a 298mm wave-type disc. ABS comes standard.
Relatively light 18-inch cast aluminum wheels are used that come with Bridgestone BT028 tires, a 120/70 front and a 200/50 rear.
Another bit of heritage retained in the new bike is the under seat tank, which provides a lower center of gravity and better weight mass centralization. Thanks to special coating, Yamaha was able to get EPA certification on the lightweight polyethylene tank. The tank holds 3.96 gallons of fuel.
The seat is low and wide, at 30.5 inches from the ground. The pillion section sits on top of the rear fender and several inches higher than the operator seat, allowing for a nice, integrated backrest, which also helps the rider stay firmly planted during hard acceleration.
Overall, the ergonomics are slightly more open. The pegs are 36mm farther back and a slight 2mm lower. The handlebars are 15mm higher and 25mm farther forward.
As for the meter displays, it would take less time to explain what they don't do. The main gauge includes a digital speed readout, a large analog tach (with a downright huge shift light mounted off to the side) and the standard indicator lights. The floodgates open with the organic electro luminescence multifunction display mounted just in front of the seat on the air box. (The organic LEDs use less power and react faster than a standard LCD.) The list includes an odometer, clock, dual trip meters, reserve trip meter, fuel gauge, gear indicator, coolant temp, miles per gallon, intake air temp, throttle grip angle, stopwatch and countdown indicator.
Riding impression
In the saddle, the Vmax never lets you forget it means business. Regardless of gear selection, rpm or road speed, you can put a smile on your face with a flick of your right wrist.
Riding the Vmax through the considerable curves found on roads over San Diego County's Palomar Mt., it's also clear that the chassis is up to the task. No, this is not a flickable motorcycle, but it feels much lighter than its 700-plus pounds of riding weight. The low center of gravity and aggressive riding position allow the bike to change direction with little effort. The Vmax holds a line well, particularly with a bit more preload on the rear shock, and has a relatively generous lean angle for when the going gets tight.
As you would expect, a motorcycle of this size and with this much mo' does not stop like a supermoto bike, but the brakes are solid and offer a very linear feel. Want to stop faster? Squeeze harder. Although we don't ride through any slick surfaces, hard braking brings the ABS to life, which does a good job of modulating brake pressure.
As you wouldn't expect, the Vmax built to a durability standard that holds up to that immense power and allows 26,000 miles between valve clearance checks does not shift like a garbage truck. The large cogs in the tranny snick from gear to gear with confidence that is, when you need them too. It's easy to get lazy on the Vmax, relying on the motor to carry you away from the stoplight when you don't feel like working your left toe.
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In town, the Vmax offers up the acceleration confidence that nothing can match your pace. The baby boomer in the Corvette? Minor league. The guy on the tricked out cruiser with the earsplitting exhausts? Your plaything. The kid in the souped-up Civic? No contest. Safety and good sense do, of course, preclude such stoplight-to-stoplight shenanigans, but the knowledge that the power's there for the times you do visit the local, closed-course dragstrip is fulfilling.
The acceleration does come at a cost above and beyond the nearly $18,000 price of entry. The Vmax drains its almost-4-gallon tank with aplomb. Don't expect to get much more than 100 miles out of a fill up.
Sure, all motorcycles make compromises, despite their R&D budgets, and the Vmax is no exception. It's not sportbike cramped, but the riding position is too aggressive for typical cruiser comfort for long days in the saddle, and the extremely thirsty motor would require too many stops for really long mile days anyhow. The Vmax shines in short trips, trips to the dragstrip, around-town hooliganism and impressing other Vmax owners (and admirers) at the local bike night.
Also, while the bike is obviously capable of more, the Vmax is limited to a top speed of 137mph. However, Yamaha says this speed is governed "by a smart system that still allows a complete quarter-mile run under full acceleration."
Final answer
The best answer to evaluating the Vmax, a 197 horsepower cruiser, then, seems to be to take stock of the qualities that balance that power. Does it brake well? Yes. Does it handle? Surprisingly well. Shift OK? Yes. Is it comfortable? No question. Is the power manageable? Absolutely.
The ability of this motorcycle to meter out its spec-sheet bursting power numbers is truly amazing. It is immensely rideable. However, while the rider always feels fully in control, so is the man with a loaded gun pointed at his own forehead, finger on the trigger. Whether the hammer drops is 100% up to him, but the consequences of doing so? Devastating. Such is the Vmax. It offers up exuberance in spades. The rationality is up to the rider.
That, though, is the point. Rationality is not this motorcycle's game. The Vmax rumbles on its own plane of two-wheeled existence. If you observe the motorcycle from any other perspective, it's out of place, but on its own turf the Vmax is undeniably king, the archetypical muscle bike. Here, a motorcycle isn't judged by real-world riding expectations. It succeeds by pushing categories to limits that few riders will ever attempt, and in doing so obliterating our expectations of what a motorcycle should be. The Vmax is irrational exuberance, precisely executed, sublimely designed.
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2008 Star Vmax |
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Engine Configuration |
V-Four, 4-stroke, DOHC |
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Engine Displacement/Cyl. Angle |
1,679cc / 65° |
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Engine Cooling System |
Liquid cooled |
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Compression Ratio |
11.3:1 |
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Valves Per Cylinder |
4 |
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Bore x Stroke |
90 x 66 mm |
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Peak Horsepower @ crankshaft |
197 BHP @ 9,000 |
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Peak Torque @ crankshaft |
122 ft.lb. @ 6,500 |
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Intake Valve Diameter |
34mm |
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Exhaust Valve Diameter |
30mm |
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Intake Valve Timing |
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Open BTDC |
29 degrees |
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Close ABDC |
59 degrees |
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Duration |
268 degrees |
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Exhaust Valve Timing |
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Open BBDC |
59 degrees |
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Close ATDC |
29 degrees |
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Duration |
268 degrees |
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Overlap |
58 degrees |
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Fuel Delivery |
Mikuni EFI w/ 12 hole Injectors |
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Throttle Valve Size |
48mm |
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Lubrication System |
Wet Sump |
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Oil Capacity (total) |
5.9 liters |
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Coolant Capacity |
4.0 liters |
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Fuel Recommended |
Unleaded Premium / 91 or higher octane |
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Fuel Capacity (Reserve) |
3.96 gal (1.1 gal) |
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Transmission Type |
5-speed |
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Clutch Type |
Wet multiplate-disc (ramp slipper type) |
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Actuation System |
Hydraulic |
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Final Drive Type |
Shaft |
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Primary Reduction (Ratio) |
86/57 (1.509) |
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Secondary Reduction (Ratio) |
22/23 x 29/09 (3.082) |
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Transmission Gear Teeth (Ratios) |
5th 29/31 (0.935) |
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4th 29/26 (1.115) |
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3rd 35/25 (1.400) |
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2nd 38/21 (1.810) |
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1st 38/16 (2.375) |
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Transmission Overall Ratios |
5th 4.348 |
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4th 5.186 |
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3rd 6.511 |
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2nd 8.418 |
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1st 11.045 |
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Frame Design |
Cast Aluminum |
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Rake / Trail |
31 degrees / 148mm |
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Wheelbase |
1700mm (66.9 inches) |
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Seat Height |
775mm (30.5 inches) |
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Front Fork Maker |
SOQI |
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Fork Tube Diameter |
52mm |
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Fork Spring Rate |
K1 = 8.3 N/mm |
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Front Wheel Travel |
120 mm (4.72 in) |
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Rear Wheel Travel |
110 mm (4.33 in) |
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Rear Suspension Maker |
SOQI |
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Shock Spring Rate |
K1 = 186.4 N/mm |
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Front Brakes |
6-pot radial mount / 320 x 5.5mm dual discs |
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Rear Brake |
1-pot / pin-slide / 298 x 6.0mm disc |
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Front Wheel |
3.50 x 18 / Cast Aluminum 5-spoke |
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Rear Wheel |
6.00 x 18 / Cast Aluminum 5-spoke |
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Front Tire |
120/70R18 M/C 59V (Bridgestone BT028F G) |
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Rear Tire |
200/50R18 M/C 76V (Bridgestone BT028R G) |
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GVWR |
1102 lb |
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Overall Length |
2,395mm |
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Overall Width |
820mm |
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Overall Height |
1,190mm |
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Ground Clearance |
140mm |
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Wet Weight |
685 pounds |
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Battery Capacity |
12V / 11.2Ah |
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Charging System Output |
VDC x Ah = 420 Watts @ 5,000 rpm |

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