Cw Comparison Bmw K75s Vs. Suzuki Katana 750

CW COMPARISON BMW K75S VS. SUZUKI KATANA 750

Germany vs. Japan for the 750 sport-touring crown

SEVEN HUNDRED AND FIFTY CUBIC CENTIMETERS may be the perfect engine size for a sporting motorcycle. Sure, 600s will scurry away in the twisties, and full-liter machines pack the biggest wallops this side of the USS Missouri's 16-inchers, but a 750 provides a wonderful combination of size, performance and affordability.

Two of the most interesting bikes in this class are the BMW K75S and the Suzuki Katana 750. Their similar engine displacements and optional hard saddlebags tie the two together, but without a doubt, both motorcycles come from entirely different schools of thought.

The K75S, the most sporting of BMW’s 750s, evolved from a series of three-cylinder Beemers, a spin-off of the four-cylinder K100 series. Following its inception in 1985, the Triple spawned the C, T and, in 1986, the S models. The greatest difference between the S and the other K75s was the suspension. Instead of plush, touringbased springing and damping rates, the K75S came with stiffer springs and increased rebound damping. The latest edition uses gorgeous, three-spoke wheels, a Corbin seat (standard on all U.S. K75S and K75LT models) and is available in two paint schemes, red or the metallic purple of our test bike.

The Katana also evolved from another model. Introduced in 1989 as a softer-edged version of the race-winning GSX-R750, the Katana 750 maintained the R’s sporting attitude with a full-fairing, wide rubber and outstanding acceleration, but mated it to a real-world riding position. We liked the result so much that the bike was named Cycle World's Best 750cc Streetbike in our annual Ten Best Bikes awards. Like the Beemer, the Katana has undergone few changes, with fresh red/black and blue/ black paint schemes the only additions for this year.

Both engines displace approximately 750cc, but similarities stop there. The BMW’s inline-Three is mounted longitudinally in a lay-down fashion. It measures 740cc and uses a pair of overhead cams to actuate two valves per cylinder, rather than using the four-valve design seen on .the new K100RS and K1 models. Compression ratio is 10.5:1 and bore and stroke is an undersquare 67mm x 70mm.

Matched with liquid-cooling and Bosch L-Jetronic fuel injection, the engine is unimpressive in the basement of its rev range, but makes very usable power anywhere above 3000 rpm. For stirring performance, though, the tach needle must be kept spinning between 6000 and the 8500-rpm redline. Vibration becomes apparent the tighter the engine is spun, even though the Triple features a counterbalancer to minimize the effect. On the plus side, it warms easily and the bar-mounted choke can be thumbed off after a few city blocks.

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Based heavily on the 1 988 and '89 short-stroke GSX-R engine, the Katana’s 748cc inline-Four sits transversely in the frame and employs Suzuki's SACS air-and-oil-cooling system. Dual overhead cams act on 16 valves, and a quartet of 36mm Mikuni carburetors handle the mixing duties. Compression ratio is 10.7:1 and bore and stroke measures 73mm x 44.7mm.

The Katana engine pulls well through the lower ranges, gains strength in the midrange and finishes with an impressive, GSX-R-like rush from 9000 rpm to the 12,500rpm redline. At lower engine revolutions, vibration tingles the footpegs, but as revs increase, the vibration fades noticeably. When cold, the Katana exhibits an annoying flat spot at 4500 rpm, which vanishes as the engine reaches operating temperature.

Both bikes feature different drivetrain types. The K75S offers a light-effort five-speed gearbox matched to shaft final drive. Unfortunately, BMW has chosen not to fit the K75 series with its highly touted Paralever system, so shaft-drive effect is quite apparent, especially in the lower gears. A combination of precise throttle control and smooth clutch release provides the best gear transitions.

The Suzuki has chain final drive mated to a six-speed transmission. Although the GSX-R/Katana series is known for its smooth-shifting gearboxes, our test model downshifted reluctantly. Switching to a premium lubricant only marginally improved the situation. Upshifts and clutch actuation were nevera problem, though.

As with the engines and drivetrains, it’s clear that BMW and Suzuki engineers weren't cribbing from each other when it came time for chassis design, either. The BMW uses a tubular-steel spaceframe which hangs the engine as a load-bearing component. Suzuki, on the other hand, uses a steel perimeter frame. Like the K75’s, the Katana’s engine is a stressed member, promoting increased rigidity. Design differences aside, both chassis are excellent, if not cutting-edge, sporting platforms.

Both bikes employ forks with 41mm tubes. While the BMW offers no adjustments, the Katana provides a threeway rebound adjuster atop the fork tubes. Positions 1 and 2 are fine for around-town and freeway use, but when cornering speeds are stepped up, the third position provides better control. Both front ends perform well in highway or leisurely backroad situations, but the Katana offers a more secure, planted feel when the pace is upped.

Out back, the K75S’s single, non-linkage damper is mounted to the frame and the driveshaft housing. Three spring-preload settings are the only available adjustments. In the number 2 position, with a 205-pound staffer aboard, both footpegs, the sidestand and the centerstand would touch down in hard cornering. Adjusting preload to the number 3 position helped the clearance problem, but left us wanting more rebound damping in bump-riddled corners.

The Katana’s linkage-equipped single shock offers seven-way-adjustable spring preload and three-way-adjustable rebound damping. For most of our riding, we left preload in its fourth setting and rebound in the second position. For heated backroad jaunts, cranking rebound to the third setting, matching the front, worked best. Overall, the Suzuki offered a plush freeway ride while maintaining control and compliancy in the twisties, providing the bike with one of the most versatile suspension packages in the business.

Each bike uses a trio of hydraulic disc brakes to manage stopping requirements. Our K75S did not have BMW’s $1100 ABS anti-lock option, but the large, vented rotors and Brembo twin-piston calipers did a good job of slowing the bike. Borrowing again from its racetrack heritage, the Suzuki stops with four-piston front calipers and big, floating discs. Initial lever travel was mushy, but the brakes are powerful and stopped the bike with authority.

Interestingly, both bikes arrive from their factories with nearly identical Metzeler rubber. The BMW’s 17-inch rear and 18-inch front rims use slightly narrower ME33 Laser and ME55 Metronic tires than the Suzuki’s wider, 17-inch front and rear hoops. We noticed an occasional twitch over rain grooves on both bikes, but otherwise, traction and wear characteristics were excellent.

Ergonomically, several areas deserve attention. The BMW’s stubby handlebar required less pressure than the Katana’s bars to initiate a turn, but created discomfort for some riders due to its inward bend. And BMW’s “ergonomically correct’’ control layout still takes some getting used to, specifically the above-thumb switchgear, which on the left activates the Fiamm horn, and on the right kills the turnsignals. \Vhile both cockpits are laid out niceR, the 13\1\\ `~ au~ie~ are easier to read. The K7~S's wind screen was desu~ned more with addi tional down lorce than optical clarity in mind, and its inherent distortion eliminates any chance of a clear \IC\\ w hile tucked-in. Suzuki’s screen presented no such problems. Both fairings provide good protection, although taller riders experienced noticeable buffeting on the BMW.

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BMW K75S

SPECIFICATIONS

$7690

PERFORMANCE

Suzuki Katana 750

$6629

The K75's BMW/Corbin seat is wide, flat, comfortable and nicely finished. Although narrower and slightly softer, the Suzuki’s perch is very good, as well. Both saddles provide long-term comfort and plenty of room for a passenger, although the Katana's seating position is more sport-oriented.

When it comes to the choice of saddlebags, the decision was unanimous: BMW. Given the German company’s sport-touring heritage, it's clear that experience pays off. Suzuki's mounting system requires almost more effort than it's worth, and once the hardware is in place, it is nearly impossible to unlock the seat release. To their advantage, the Katana's bags are easier to open and shut, but they require an additional key, while the K75's unlock with the bike’s ignition key. Also, the Beemer's bags are less expensive and better-engineered. They hold more and are neatly integrated with the bike’s lines. Both sets of luggage are optional equipment, available from each manufacturer's accessory line and priced at $461 for the K75S and $630 for the Katana, complete with all necessary hardware.

In the end. what we have here are two 750-class machines, each with a distinct character. Ridden smoothly, the K75S is a rewarding and capable motorcycle. Ridden with a heavier throttle hand, the bike becomes confused and can feel awkward. Compared to the Katana, the BMW is underpowered and its suspension isn't as good. In its element, though, the K75S is a superb piece and begs for the open road and long stretches of smooth pavement spiced-up with high-speed sweepers.

T he Katana draws a somewhat different image. As long-legged as it is. the Suzuki is just as at home in tight going, its engine spinning in the upper reaches of its powerband. While the Katana can lope happily alongside the BMW, it can also turn up the wick and leave the Beemer in its wake, and do so for $ 1061 less.

For those riders seeking a complete sport-touring package, capable of devouring days of adventure-filled miles, the K75S is a terrific motorcycle. But. if you préféra sharper-edged sportbike with a touring option, look no farther than the Katana 750. ¡S