Vintage_Mania
1979 Honda CB400T
Just in case you hadn`t noticed, there aren't very many motorcycle manufacturers in this country, In fact, there is only one U,S, motorcycle company in the top ten: Harley-Davidson, And even though they are in fifth place, behind the four big Japanese manufacturers, Harleys only account for five or six percent of U,S, bike sales. At first glance, that situation seems rather incredible. Here we are, the most prosperous, resourceful, allluent nation in history, and the biggest, most important motorcycle market in the world. And yet there are 19 or 20 foreign motorcycles sold here for every domestic one. The reasons are many and complex, and in some cases, unclear. There`s the age-old production cost factor, wherein the expense of U.S. labor and raw materials causes the retail price to skyrocket. And because there hasn`t been much motorcycle building in this country in recent years, there`s a shortage of knowledgeable, experienced motorcycle designers and engineers, and an equal lack of competent executive types capable of successfully running a motorcycle manufacturing operation. Furthermore, it`s difficult to obtain electrical components, suspension units, wheels, brakes, fenders, fuel tanks, and all the other parts usually purchased from outside vendors. And who will build the engines? That`s a complete hassle in itself. You can get someone to manufacture all these things for you, but the minimum quantities they`ll consider making are usually about ten times greater than the maximum quantities you`ll need. So it keeps boiling down to money. The big companies can build motorcycles, but don`t want to. The little companies want to, but can`t. The few small manufacturers that briefly survive usually run out of money before they get a competitive product going, so they turn it loose on the public before it`s ready, in hopes of raking in some capital. They soon tind out the hard way that motorcycle owners make poor R&D people, at least from a promotional standpoint. An unhappy owner is the worst advertisement a company can have. Harley-Davidson`s case is different. They are the sole surviving American manufacturer of years past. Their bread- and-butter models, the 1200cc FLS and l000cc Sportsters, are sold to a more-or- less captive market. Their basic designs originated decades ago, so Harley`s retooling costs have been minimal and spread out over many years, They have not built any all-new U.S.-made models because their sale price would have to be astronomical. From this evidence it appears that, at the very least, starting a motorcycle company requires money, experienced manpower, manufacturing facilities and know-how, near-complete control of accessory vendors, and the ability and willingness to operate in the red for several years until you get matters under control. That`s a pretty fair description of the situation at Bombardier Ltd,. manufacturers of Ski-doo, the world`s largest and most successful line of snowmobiles. Snowmobiles are in no way motorcycles, but the manufacturing problems and marketing requirements ofsnow machines parallel those of motorcycles more closely than any other industry. Bombardier was a logical firm to build motorcycles. They wholly owned Rotax, an engine manufacturing facility in Austria; they had their own liberglass plant: they had their own fabric and upholstery plant; they had their own assembly lines; they had valuable R&D experience with two-stroke engines; and they either owned or had good relationships with outside vendors. They were a solid, experienced firm with heavy assets. In l970 Bombardier formed the Can-am Division and started hiring good motorcycle people to design and build motorcycles. Even though Can-am is a Canadian company, there are now enough U.S.-born employees in important positions at the Valcourt, Quebec, plant to sort off qualify it as an honorary U,S, company. ln fact, the Division is headed up by an ex- Californian, Gary Robison, who is the motive force behind the Can-am bikes. There`s also a prominent Englishman there: Jeff Smith, two-time world motocross champion and winner of numerous British motocross and trial championships. He is the head development consultant and is responsible for much off the Can-am design. Last year the first production Can-ams, 175 and 125 enduro'ss and motocrossers, started showing up throughout the rather sketchy dealer network. The bikes were well-received by the motorcycle press, mainly because of their powerful, compact engine and innovative general design, Over the winter Can-am hired Gary Jones and New Englander Jimmy Ellis to ride the AMA motocross nationals on prototype 250s, and at the same time, continued building their dealer organization. By fall Jones had clinched his third straight national 250 title, Ellis had finished third, and the production 250 was on sale at Can-am dealers nationwide. Marty Tripes linished the AMA circuit in second place on a Can-am, although he was a year-end acquisition and had accumulated most of his points on a Husqvarna. But technically, it was a one-two-three sweep off the 250 class by Can-am, and they did it on their first try. Obviously, the Can-am people have what it takes to make it in the motorcycle business. What we`ve seen off their machines has been quite impressive, especially considering the fact that they are relative newcomers to the industry. So we anxiously awaited the opportunity to test the 250 MX-I, It is not exactly like the bike that carried Jones to the national title, but it reflects much off the technology that can only be learned in actual competition.
THE BIKE: The 250 Can-am engine is a masterpiece of compact, uncluttered design. It is the same basic power plant used in the l25 and l75 Can-ams, and with the exception off a more massive cylinder and head, you can`t tell the dilfference. The narrow, cleanly styled engine covers belie the fact that beneath them is a rotary-valve induction system, a Mikuni gear-driven oil injection pump, a Bosch CDI ignition, and a hefty 12-plate wet clutch. The bore and stroke are unusually oversquare at 75mm and 57,5mm, equaling 247,2cc. The rotary valve disc mounts on the left side of the engine, allowing incoming fuel to enter directly into the crankcase during the piston`s upward travel. A 32mm German Bing slide needle carburetor mounts at the beginning of the long intake port, to the rear of the engine. Four transfer ports get the mixture up to the combustion chamber, and a large, unbridged exhaust port gets rid of the exhaust gases. The cast aluminum piston uses a Dykes-type compression ring and a conventional flat second ring, The wrist pin rides in a small caged needle bearing at the top of the connecting rod, and a larger caged roller bearing surrounds the crank- pin at the bottom. The pressed-together, three-piece crankshaft spins on two large main ball bearings. The right bearing is conventional, but the left one is a wide, double- row ball bearing which helps handle the extra load placed on the left bearing by the primary drive. An unusual feature is the use of plastic bushings between the main bearings and the bearing mount holes. The aluminum engine cases expand at a greater rate than the steel ball bearing reces as the engine gets hot, so the plastic bushings around the bearings compensate for the expansion differences. As a result, the bearings don`t get loose when the engine is warm, so the crankshaft spins true at all times. Straight-cut gears deliver the primary drive to the wet clutch and five-speed gearbox. Primary kickstarting allows in-gear starting with the clutch disengaged, so you don`t have to fish for neutral before kicking. Unlike the l25s and l75s, the 250 uses a downswept expansion chamber. This gives the 250 about two inches less ground clearance than the smaller bike because the pipe runs directly under the engine and is protected by a contoured steel skid plate on the bottom. The stinger and rear section of the pipe incorporate a very efficient muflier that allows only 94,7 decibels of exhaust noise to escape into the atmosphere, The Can·am's frame is another of its well thought out features. lt's a tubular steel, double-downtube affair with a hollow, large-diameter tapered backbone that serves as a 2,3-quart reservoir for the oil injection system. The steering head angle is adjustable 13 ways, from 26 to 3l degrees in 1/4·degree increments. The steering bearings rest in eccentric cones inside the steering head, one at the top and one at the bottom. The cones come in four degrees of eccentricity, and the direction off their offset in the head determines the steering angle. The bike is shipped with a 30·degree angle, and by reversing the stock cones, you can change the angle to 26 degrees. lf you wish to try any other angle you have to purchase the correct cones. The cone numbers and a head angle chart are included in the owner’s manual. All that is missing is a booklet or a section in the owner`s manual that tells you when and why to change the head angle. The 250 MX-l uses Spanish-made Betor forks up front, but the dampening action has been changed by Can-am. Breathers on the stanchion nuts and deflectors above the internal oil control holes give the forks more consistent dampening characteristics. The Betors provide an honest 6 inches of travel to the front wheel. A 3,00 x 21 Yokohama knobby mounts on a WM-1 shouldered alloy rim, laced to a beautifully polished conical alloy hub. In the rear the suspension is by S&W shocks with live way preload cams for the 82 pound springs. The rear suspension has been given a mild LTR (long-travel rear) treatment by moving the shock mounts forward a few inches, The result is 4,1/4 inches of rear wheel travel. Cam-type adjusters give about an inch of movement for taking up slack in the number 520 drive chain. A 4,00 x l8 Yokohama knobby mounts on a WM-2 shouldered alloy rim, which is laced to a conical hub similar to the one at the front, The Can-am uses plastic body components made in Bombardier`s own plastics and liberglass works. The 1,9-gallon gas tank, both fenders, the still air box beneath the seat, and the front and side number plates are all plastic. And the firmly padded seat is also a Bombardier product, made in their nearby upholstery plant. The Can-am is an incredibly well finished and assembled motorcycle. The welding is smooth, the castings are flawless, and everything fits together properly. There is a multitude of beautifully machined little spacers and fittings and grommets used throughout the machine which indicate the kind of thought and care that has gone into its construction. Even the Japanese, with their highly touted quality control and their reputation for craftsmanship, don`t build them any nicer than this.
ENGINE AND GEARBOX: The 250 MX-l was a one- or two-kick starter every time but once. We never even needed to use the tickler button on the carb. The one time it refused to start, we had to remove the plug and install a new one. The crankcasc had gotten loaded up with raw gas after we parked it and left the fuel petcock on. The engine fired up with the new plug, but it was off the wrong heat range, so as soon as the engine cleared out, we put the old plug back in and it worked just fine for the duration of the test. Despite its tame, ring-ding exhaust note, the 250 MX-l is a jet - perhaps the fastest 250 motocrosser we`ve tested. The rotary valve keeps the engine from being peaky, even though there definitely is one point in the rpm range where the power starts coming on noticeably stronger. The engine idles perfectly and chugs around below 6000 rpm almost like an enduro bike, (Actually, the 250 T`NT, the enduro version off the MX-I, uses the same engine, except it has a heavier magneto flywheel, lower first and second gear ratios, and higher final gearing,) lt`s almost impossible to bog the engine, even at incredibly low revs in the higher gears. The acceleration below 5000 rpm isn`t fierce, but it is smooth and steady. Between 6000 and 6500 the engine comes to life. lt suddenly starts pulling harder and harder until the power peaks at 9000 rpm. At 9500 it`s all over with, and you`re better off upshifting rather than trying to wring a few more rpm out of it. But between 6500 and 9500 the Can-am`s power is really impressive for a 250. Bunches of horsepower are meaningless if they never get to the racetrack, and in that respect a stock Can-am needs a little help. The Yokohama rear knobby doesn`t latch onto the ground like some better tires, and very often the Can-am`s power ends up in futile wheelspin. But when the rear tire gets traction and the engine is in the powerband, the Can-am hurtles down the straightaways better than most open class bikes. Even in those higher gears you can feel the acceleration sliding you back on the seat and pulling at your arms and hands. First gear is needed for starting and perhaps for super-slow, 180-degree hairpin turns. Otherwise, second gear is as low as you`ll normally need to downshift on a motocross course. And unless you ride on a big, fast GP course, fifth gear is one that you`Il seldom use. The gear ratios are just about right for a fast, serious 250 motocrosser, but it takes a big racetrack to use all five speeds. The spacing between the gears is generally correct, although fourth gear is closer to fifth than it is to third, for some unknown reason. This doesn't cause any problems, but when accelerating up a hill, you must remember to rev the engine at least to its peak power rpm before shifting from third to fourth. lf you don`t, the initial fourth gear acceleration will be a trifle lazy until the engine gets into the meaty part of the powerband. The MX-I makes a good cow-trailer, as long as you don`t get into the real tight enduro stuff , The bog-free low-end lugging power allows you to negotiate water crossings, ride in heavy sand, and climb moderate hills without the need to keep the engine screaming. lf you try a steep, slow climb, you may have to slip the clutch often to make it to the top. The overall first gear ratio is about the same as the T`NT Enduro, but the lighter flywheel in the MX-I makes the slow ridinga bit more diflicult. The MX-I engine is also well suited for desert racing, hare scrambles, and even T.T. Competition. Its superb top-end performance is equal to or better than that of other 250s, and many larger machines would like to be capable off the Can-am`s performance. We were also impressed with the mechanical functions of the engine. The clutch engagement was always smooth, progressive, and free of slip or drag. The shifting mechanism and gearbox worked flawlessly, permitting easy, positive gearchanging every time. And despite an absence of rubber or metal sound-deadening buttons between the cylinder and head fins, there was very little mechanical clatter when the engine was running,
HANDLING: Since the Can-am`s steering geometry is variable, you can dial it in to suit many different requirements. We tested our MX-I only with the standard 30-degree setting, which we felt was just fine for all-around motocross use. We didn`t have any other steering cones to try, so we can`t report on how the front geometry works at other settings. At the 30-degree location the front wheel has about 5 inches of trail. At the steepest setting, 26 degrees, there`s around 4 inches of trail, and about 5 1/2 inches at 31 degrees, As a general rule of thumb with the Can-am, a one-degree change in steering angle results in a quarter-inch change in trail. At 30 degrees the front end performs all its required motocross duties nicely. The bike turns corners easily and goes wherever you point it over most types of terrain and around all kinds of corners. The one possible exception might be very sharp, smooth corners that have a loose surface. ln those turns the front wheel sometimes skates noticeably, and you must back off the throttle and wrestle the bars to get the bike turned. Sitting way forward at the very front of the seat helps, but even that sometimes doesn‘t work. Rather than fault the geometry, we suspect the front 3,00 x 21 Yokohama knobby to be the culprit. Changing to a well-proven tire better suited to the terrain in your area would more than likely clear up this turning problem. Other than that occasional skating problem, the MX-l`s cornering ability is quite versatile. It likes being bounced off a berm, and if you wish, it does really neat, controllable, full-lock slides on smooth corners. Regardless of your cornering style, the Can-am will accommodate you. The 30-degree geometry also makes the a front end stable at high speed on long, rough straightaways or fast fire trails. You don't need a death grip on the bars when you go fast, so your wrists and forearms don`t tire as easily. The Can·am/Betor front suspension is also excellent and contributes even more to the beautiful behavior off the front end. The forks are firm enough to prevent continual bottoming, but are also soft enough in the middle of their travel to absorb bumps and ripples and holes in the track surface. Even when rounding an extremely rough corner, the forks keep the front wheel on the ground as much as possible. Unfortunately, the rear suspension is not as good as the front. The S&W shocks don`t have much compression damping, so we must assume that either the 82- pound springs are much too stiff, or the rear suspension geometry is all wrong. With a l85-pound rider aboard and the springs set on the softest preload, the rear suspension is still too stiff. So regardless of any other problems, softer rear springs would surely help. The stiff rear caused quite a few handling problems on anything but a smooth TT track, lf we sat down over big Woops, the rear suspension would deliver a bone-jarring blow to our body, often popping us way up off the seat. lf we stood up over the same bumps, the back of the bike would fly up and slam us in the rear end. In a few instances, where there was a steep rough downhill entrance to a slow corner, we ended up unicycling on the front wheel because the bumps had kicked the rear end a foot or two off the ground. The rear wheel never used more than 3 of its 4 inches of travel, even though the back of the bike was continually kicked skyward. The rear suspension also gets the bike out of shape over some types of whoop-de-dos. If the successive bumps are fairly smooth and relatively far apart, the Can-am handles them nicely, without getting sideways or bouncing the rear wheel into the air. But on those closely spaced series of big bumps that are so common on motocross courses, the Can-am often gets out of hand. The rear end starts popping up in the air first, and immediately there- after, the whole bike gets sideways and starts fishtailing. We were amazed that we didn`t do a crash-and-burn number frequently when it happened. This indicates that the bike is inherently stable, but the back end apparently doesn't know it. The Can-am`s handling is also hindered somewhat by its weight, which is 15 to 30 pounds more than the latest batch of 250 motocrossers. The 233-pound dry weight isn`t too noticeable until you round a slow, rough corner. lt then feels rather clumsy, and you find yourself taking longer to get through those corners than on a lighter 250. The weight is also evident when the bike starts bouncing around. lt`s quite a bit more dillicult to muscle the bike back into control than some other, lighter machines.
