Gsxr 1000 k1 2001

SUZUKI MOTORCYCLES GSX R 1000 k1

Gsxr 1000: the big one

Members of the press and enthusiasts had expected Suzuki moto to rejoin the open class.
It just had to. By 2000, Honda had an uprated version of the CBR 929 RR, Yamaha continued to refine the YZF R1 - a bike thought by many to be the most significant model in this new generation of lightright sportbikes to follow in the wheel tracks of the original Gsxr - and Kawasaki gamely kept the ZX 9 R on the development track. You can imagine the debate inside Suzuki moto.

The Gsxr 750 placed extremely well in many Superbike shootouts of the period, partly because its mighty engine produced nearly the same peak power as the Honda's. Why develop a new 1000 cc model when the Gsxr 750 was doing just fine? It's unlikely the debate lasted long, however.
The other liter bikes were selling quite well at a reasonable profit margin for the other manufacturers. And at the same time the 1000 cc V-twins were running away with AMA Superbike and world Superbike racing, the push was beginning from inside those sanctioning bodies to switch to 1000 cc fours for racing. In addition, Suzuki moto was not content to watch a reenactment of the Honda-Yamaha war without jumping into the fight. The result was the universally lauded Gsxr 1000.
From the start, the big Suzuki Gsxr 1000 k1 dominated, producing 142 rear-wheel horsepower to the Yamaha's 130. It was light, astoundingly fast, and yet as docile as such a high-performance motorcycle could be. when the early press materials arrived, some were surprised that it didn't look a lot different than the Gsxr 600 k1 and Gsxr 750 k1.

The Gsxr 1000's chassis

Indeed, from perusing the specifications, you'd think it was little more than a tweaked Gsxr 750. These first impressions couldn't have been more off the mark.
It's true, however, that Suzuki moto heavily leveraged the Gsxr 750 to create the Gsxr 1000 k1.
The frame was essentially the same, as was the majority of the bodywork (the lower fairing was slightly different).
By altering materials in the alloy frame, the Gsxr 1000's unit was 6 percent stiffer than the Gsxr 750's; the swingarm was stiffened by 1 percent.
Nothing major, in other words.

Two of the prominent visual cues were the wider rear tire-a 190/50VR17 on a 6.0-inch-wide rim-and the gold-colored fork tubes. Suzuki moto turned to Kayaba for a new fork finish to reduce seal friction (sometimes called stiction) and got back an inverted fork with a titanium-nitride finish. while the fork has your attention, perhaps you'll notice the six-piston brakes in place of the Gsxr 750's four-pot units.
Still, from five steps back the Gsxr 1000 k1 didn't seem to be much more than a big-bore Gsxr 750. Again, the assessment understates the reality.
As soon as press bikes started to hit the dyno, the world of open-class street bikes was turned on its head. Most competitors were turning out 125 to 130 hp at the rear wheel, but the 2001 Gsxr 1000 k1 pounded out around 143. This was not an incremental improvement but rather a showstopping, tire-screeching change in direction. The horsepower wars were over before the others could so much as cough.

Engine and more torque

Perhaps most impressive about the 2001 Gsxr 1000's power dominance is that it came from an engine virtually identical to the Gsxr 750's and, according to most tuners, in a fairly mild state of tune.
Suzuki moto chose to use as much of the Gsxr 750 as possible, so the Gsxr 1000's bore increase was limited to 1 mm.
The rest of the boost to 988 cc would have to come from stroke, which traditionally benefits torque production more than an increase in peak power.
The Gsxr 1000's 59 mm stroke was the longest in the class in 2001. What's more, Suzuki moto had the audacity to use the Gsxr 750's cylinder head essentially unchanged.

Common wisdom was that valves ideal for a Gsxr 750 would be prohibitively small for a Gsxr 1000 k1. Even the intake system was borrowed straight from the Gsxr 750, with some minor changes and the requisite computer reprogramming.
The servo that controlled the secondary throttle body was now mounted right to the throttle-body rack, not remotely as before. This change would come to the Gsxr 750 in 2002 along with an extremely clever fast-idle system. Before, there had been a small lever on the handlebar to raise the idle speed for starting.

The new system-arriving across the board in 2002-used a small cam mounted to the secondary throttle shaft to open the primary throttle slightly.
It did this by forcing the secondary throttle valve slightly over center. As soon as the rider opened the throttle, the secondary system could return to its partially closed state to manage airflow.
As the engine warmed, the secondary system returned to normal operation.
Suzuki moto didn't pull out the engineering stops to achieve its class-leading peak power, suggesting that Suzuki either had modest ambitions for the Gsxr 1000 k1 or-as it turns out was more the case-it was sandbagging, keeping a bit in reserve until its competitors responded.
That isn't to say the Gsxr 1000's engine didn't have some tricks of its own.

Increased heat output made a traditional oil cooler necessary, fitted to the chin fairing.
The 73 mm pistons were, amazingly, even lighter than the Gsxr 750's 72 mm slugs.
Changes were made to the upper and central crankcase castings for two reasons.
One was to accommodate the 13 mm-longer stroke.
The other was to introduce a technology to the sportbike class that would have a great impact on the bike's demeanor: a crank-driven counterbalancer. When an inline-four gets to a certain size, vibration can become a big issue, both for component longevity and for rider comfort.

Suzuki moto developed a simple counterbalancer positioned on the crankshaft split line and hung out in front of the engine.
In theory, this was not the most effective place for a balancer, but it was offset by the fact that it was up out of the oil supply, which reduced windage drag.
Suzuki's engineers worked extremely hard to reduce the weight impact of the balancer shaft as well as any power losses associated with it.
As such, it ran on plain metal bearings and was gear driven from teeth cut into a crank balance weight.

The primary benefit of the counterbalancer is the Gsxr's uncanny smoothness. Most liter bikes of the period were built with low weight in mind, so the engines had become solidly mounted to the frame. Some vibrated intensely at certain engine speeds.
Throughout the rev range, particularly in the midrange cruising speeds, the Gsxr 1000 was eerily serene.
The combination of the Gsxr 1000's incredible top-end rip and its meaty midrange-better than all its competitors'-gave the bike exemplary flexibility. "We can thank the 2001 Gsxr 1000 for the unbelievable state of liter bike performance we enjoy now," comments Kent Kunitsugu, Sport Rider editor. "All of the open-class machines previous had street bike compromises in their design; the '01 model basically took the gloves off and laid down the gauntlet that others have had trouble responding to ever since." To say the Gsxr 1000 k1 changed the face of liter bike performance is a raw, almost egregious understatement.

For 2001 and 2002, it was the undisputed king of the class. Yamaha gave the R1 a mighty shove up the performance ladder but couldn't reach the Gsxr 1000 k1.
Honda immediately moved up development of the CBR 929 RR and created the stopgap CBR 954 RR. Kawasaki all but gave up with the ZX 9 R.
In fact, it would take until 2004 before the competing manufacturers could mount a serious challenge to the Gsxr 1000's utter and complete dominance of the class.
But by then it was nearly too late for them. More improvements, more racing experience, and more development were in store for every Gsxr on the menu.