Yamaha XJ 750RJ Sega
The 750 Seca is gone; Long live the 750 Seca. That's what it comes down ■to. A case of add-ons becoming standard. Your basic lesson in evolution: only the fittest will survive. And what has persevered here is Yamaha's dressed version of the swoopy 750 Seca, once a factory option. The sport version of the 750 has been dropped from the 1983 line-up. Sports touring is now king. Basically, the XJ750RJ (as opposed to the non-dressed XJ750RH, never mind what happened to the I) hangs a sport fairing, complete with lowers, touring trunk and saddlebags onto the Seca. The nuts-and-bolts, for the most part, are unchanged. The bike still has shaft drive, anti-dive forks and a blinky-blinky console monitoring system right out of Ray Bradbury country. The new combination works well. The sports Seca 750 was intriguing enough with those standard features, but it didn't fare all that well against some of its competitors. It wasn't the fastest or the quickest 750. It wasn't the lightest or the best handling. What it was, was the most expensive bike in the 750 class. Quite a few drawbacks in a very cutthroat league. So, the folks at Yamaha have created a new league. It's called Touring-in-Sporty-Style. You get the storage capacity of bags and a box, and you get a fairing that looks nice and works well. The head has two valves per cylinder, with the spark plugs located in the side of the domed combustion chambers. The intake tract offers Yamaha's patented YICS (Yamaha Induction Control System), which is something of a holding pattern cast into the head to distribute the intake charges more evenly. The engine is similar to that of the XJ650 Maxim powerplant introduced in 1980, with one excentinn- the 7^n Because the engine hasn't been changed, claimed power and torque of the dresser are the same as those of the sport version. Yamaha claims a horsepower rating of 76 bhp at 9000 rpm for the Seca 750, and 44.9 lb.-ft. of torque at 7500 rpm. What has changed, and not for the better, is performance, a trade-off related to the extra 58 lb. of fiberglass packed by the dresser, which weighs in at 561 lb. with a half-tank of gas. At the strip, the dressed Seca 750 turned 13.04 sec. on a 100.89 mph run, down a good bit from the sport version's 12.34 second run at 106.63 mph. Half-mile top speed is down just a shade, 114 mph compared to the non-dresser's 119 mph. But while performance of the dresser suffers because of the extra weight, fuel mileage doesn't. It recorded 54 mpg on the Cycle World mileage loop, a mix of city, country and highway riding, a figure almost the same turned in by the sport version. The good showing can be marked up to the streamlining effect of the fairing .and luggage. According to Yamaha, the luggage system, fitted by itself, reduces drag by just under 1 percent. With only the fairing and lowers fitted, the factory says, drag is cut by more than 3 percent. And with both the fairing and luggage fitted, Yamaha claims, drag is reduced by more than 6 percent. The Seca 750's braking system appears conventional enough—until you start looking for the master hydraulic cylinder that operates the front brakes. It's not on the right bar, where tradition says it should be. Where it is, is behind the headlight, between the fork legs, at the end of a cable that begins at the front brake lever. Yamaha apparently opted for that approach to rid the bars of an appliance-cluttered appearance. And the bars . . . well, stalks might be a better word. The handlebars are hidden and shaped by a pair of futuristip plastic covers, creating, sure enough, a sleek, clean look, but one that takes a while to get used to. Other than the hidden master cylinder, the rest of the braking system is business as usual: dual 11.6-in. discs up front, a 7.9-in. drum in back. Braking is excellent—127 ft. at 60 mph. The anti-dive front suspension is linked to the brakes; it uses brake fluid pressure to restrict oil flow through the fork damping holes, and has a blow-off valve to permit suspension movement if you hit a hard bump while braking. The setup also helps keep the bike flat and stable during hard braking. The forks still dip a little, but the movement is smoother, less abrupt and less exaggerated than the reaction exhibited by other bikes under similar circumstances. The front suspension is adjustable in two ways. The damping of the anti-dive system can be changed by turning a screw beneath the anti-dive fitting on each fork, an adjustment that changes the amount of oil restriction as the forks compress. In addition the forks have air fittings, so pressure inside the fork legs can be tailored to riding conditions. Rear shocks: nothing startling here. Two, with the usual adjustable spring preload and adjustable rebound damping. The Seca 750 will tell you. If one of the sensors indicates a potentially unsafe condition, a red light on the instrument console begins blinking insistently, and a liquid crystal display will advise you where the problem lies: BATT, for example, or STND or FUEL. Don't just sit there, do something, the bike says. As soon as the engine is started, the warning console runs through a pre-ride checklist, the readouts flashing on and off in succession, to let you know whether it's safe to take off. "Damn if the thing don't talk to you," said one bystander as he watched the console check everything but prevailing wind conditions. On the road, you can push a button, and the readouts will do a quick run-through. Another button activates a warning override system. Say you're on the freeway and the red light starts flashing as if it's warning you of an impending crash. A check of the readout shows that you're running low on gas. One push of the override button ends the flashing; instead, the red light just glows as a warning. A second push extinguishes the red light altogether. The angle of the fairing helps control front end lift besides parting the wind directed at the rider. Lowers extend to the top of the case covers. The clear windscreen comes up to chin level on the average rider. Inside, there's not much to tell: a cigarette lighter and a couple of small, lockable storage compartments. The bags and box are designed to blend in with the curvy style of the Seca 750's tank and side covers. The luggage is some of the nicer-looking equipment available. Even riders with no fondness for luggage found the Seca 750's system eye-appealing. The trunk will easily hold a full-face helmet or a couple of six-packs of longneck bottles. A pad provides a comfortable backrest for a passenger. The bags are hinged at the bottom, and fold outward for access. Use Time to crank it up. Lever back the choke with your left thumb and hit the starter button with your right. No throttle, or the Seca 750'H be a little reluctant. The choke is an enrichening circuit in the CV carbs, and the engine starts easiest with full enrichment and no throttle. A couple of moments later, time you can pass by watching the red blinky and the flashing checklist, and you can ride off, still on choke. Watch the first few stops; hard braking to a stop will flood the engine as long as the choke is on. In cool or cold weather, it'll take a few miles before the Seca 750 will run as it should on a normal air-fuel diet. The sculptured seat grows hard and, no matter how much you squirm, the dip will keep forcing you into the one and only seating position. Which, by the way, could get slightly crowded if you're riding two-up, because the passenger will also try to slide down into the well. Handlebar height is comfortable, but the grips could be longer; they're rather short for a rider with average-size hands, let alone anyone with a real set of paws. The footpegs, shift and brake levers are set a bit too much to the rear. They were fine on the sport version of the Seca 750, but tour a while on a low seat with your legs bent in a cafe-racing tuck and you might end up with the old pins-and-needles from the waist down. Handling, especially for a luggage-equipped bike, is very nice. Cornering clearance is excellent—more than you'd normally use on a touring mount. The problems of shaft drive—rising and falling of the rear end during abrupt throttle use—are of smaller concern now that the Seca's mission in life has been reordered. On a sport bike, the ups and downs were drawbacks; on a tourer, ridden with a more restrained hand on the throttle, shaft-related suspension problems almost are non-existent. The unloaded Seca 750 rides rather harshly, but pack a few pounds of luggage or mount up a passenger and the chop smooths out. Point the bike straight ahead and that's just where it goes. Except when you begin to push 85 mph or so, when the front end starts to wander just a bit. It seems to be more of a fairing-related aerodynamic effect that a suspension problem. Vibration is unnoticeable, except for an occasional buzz in the bars. A steering damper has been added with the fairing. Steering effort remains remarkably light, though, and the Seca retains its ability to change directions quickly and easily. Performance, already down because of the added weight of the luggage, obviously will drop even more as the dresser is loaded with cargo. Still, there's adequate power for a long haul, although it's located kind of high in the rpm scale for a touring bike: in the vicinity of 7000 rpm up to the 10,000 rpm redline. And for pick-up-and-go, or for passing, the Seca demands that rpm. We've said already that the solidly mounted luggage is quite attractive. Right. And aerodynamic. Right, again. Yamaha's designers triumphed in those areas. Convenience, though, didn't get the same attention. Packing the side-loading bags is harder than packing top-loaders. Also, the unusual configuration— longer at the top than the bottom—means some items may have to be bent, folded or otherwise mangled to get them packed. For such a spacious storage space, the trunk sure has a small opening. But the biggest inconvenience is this: to get underneath the seat to the battery, or tool kit, the trunk must be unbolted and removed. Even then, the seat must be forced and bent against the right saddlebag. There has been. On the one hand, this; on the other hand, that. That's the nature of this beast. On the one hand, the Seca 750 is a sport bike; on the other hand, not exactly. On the one hand, it's a tourer; on the other hand, maybe not. Sounds like a major-league identity crisis, but instead it's the Seca 750's-strong-est point. So, maybe it's not the bike you'd pick for a morning of peg-scraping the switchbacks. Maybe it's not what you'd take on a trans-USA blitz of the interstate system. But it's exactly what you'd need for a sporty, four-day jaunt to, oh, say the border to grab some enchiladas and a six-pack of Tres Equis. Good parts of both worlds, that's what this bike has.H Source Cycle World 1982 |
1982年Yamaha XJ 750RJ Sega
2013/8/2 10:04:00