The Motorbike Archives

As a small European manufacturer, Montesa stands in an interesting relationship to the leading (predominantly Japanese) innovators. Montesa simply can't afford to follow all the trends. Their engineers must sort through the barrage of new port designs, reed-valve systems and suspension components and select what they think works. Consequently, like most new models from Montesa, the Enduro 360H combines a curious blend of old and new, successful and unsuccessful ideas.

Gnarled old enduro veterans will most appreciate many of the 360H's innovative items, which are low-cost, clever and could have been developed (and maybe were) by experienced, pragmatic garage-mechanic types. For example, five heavy-duty rubber and metal attachments secure the seat and gas tank. To get to the tool box or electrics takes no more than 15 seconds. Both the shift lever and countershaft sprocket are spring-loaded (at their respective shafts) and held in place with clips; simply push in the lever or sprocket to compress the spring, remove the clips and slide off the part.

The shift lever removes in 1.5 seconds; along with the brake and clutch hand levers, the shift lever is the most easily breakable necessary part on the bike. In competition, this feature can save minutes in repair time. Though the countershaft sprocket theoretically removes as easily, we needed a screwdriver to work the clip off. Getting to the screwdriver under the seat takes 15 seconds, and removing the sprocket after that takes another 35 seconds. In view of the fact that riders rarely if ever change countershaft sprockets during an event—when time is of the utmost importance—we think Montesa succumbed to the temptation to use unnecessarily what may become a trendy innovation. Other proven and functional items on the 360H include a hefty and large grab-handle and a centerstand.

But where the peripheral items reflect a willingness to innovate with minor features, the heart and guts of the 360H—the engine, frame and suspension—reflect the factory's determination to produce a familiar, mechanically straightforward motorcycle. The difficulty Montesa appears to have had is determining which recent major technological developments are actually progress. They've acted very successfully on basic two-stroke engine theory and have a powerplant which is competitive with the latest, trickest maxi-ported engine. But they seem to have made only a half-hearted attempt at incorporating recent suspension advances, and the result. is a generally lousy-handling bike. The trick fork and shock designs developed in this decade, after all, do work.

The Enduro 360H engine is a variation of the 360VB powerplant, which in turn was an extension of the 360VA unit. The basic Montesa big-bore engine has a history of slow change; its major refinement was accomplished in the 1977 model year. The 1976 360VA motocross engine had its clutch mounted on the left side of the crankshaft, which resulted in a couple of benefits. First, lighter crank flywheels could be used because the clutch was storing a large amount of inertia. Next, because the clutch was transferring unmultiplied engine torque, the clutch itself could be smaller and lighter. However, there was an overwhelming disadvantage: the crank was forced to endure an unusual amount of stress, and the clutch was supported entirely by the left-side crank bearing. Understandably, crankshaft failure was a threat the VA made good on all too often. The updated 1977 VB had a crank-mounted, straight-cut primary gear which drove a gear on the clutch, as do most motorcycles. The 360H uses this design.

Other specific engine parts have been refined. The pressed-together, ball-bearing-supported crankshaft is now beefier, as is a new connecting rod. All three models have used the same 83 x 64mm bore and stroke, but the 360H uses a German Mahle piston with two Dykes rings where the VA used a single-ring piston. The VA and VB used four-speed transmissions; the Enduro uses a six-speed gearbox developed for the 250H. Gear selection is via two shifting forks and two sliding circular driving dogs splined to the countershaft.

The 360 engine's basic design has remained the same. For years, the cylinder and head fins have had rippled construction, which makes them a little stronger, offers more surface area for cooling and cuts down on ringing. Another carry-over from the VA to the VB, and consequently to the 360H, is separate oil compartments for the gearbox and the primary case. This separation allows the gearbox to use its recommended 20/40W oil and the clutch its recommended 10/30W oil.

Montesa tradition means torque, and the carburetion, cylinder porting and upswept exhaust pipe all work together to produce a broad, firm powerband. The 36mm Bing carb is about average in size for a 360. A straightforward and simple porting system carries on the pursuit for mid-range power. Only one boost port and two transfer ports connect to the combustion chamber. The boost port is of the scoop design, which breathes fuel to the top end directly through a small hole in the upper rear of the piston. A medium-size squish band in the cylinder head concentrates the charge over the center of the piston to help control detonation. The large exhaust port—which brings the total to five ports—completes the system. Some bikes have nearly twice that many transfer ports, but more is not always better. The 360H engine is strong and efficient: on the dyno it pulled a load from 3000 rpm, made 18 horsepower at 5000 rpm, and produced from 26 to 28 horsepower from 6000 to 8500 rpm with a peak of 30.85 at 7500 rpm. This is excellent: strong in the mid-range, reasonably good on the top end and slow to drop off. Over-using the gearbox is not necessary, Jut over-revving is not a penalty either. Much of the credit for the engine performance must go to the actual construction Of the cylinder. Liner-to-cylinder alignment is superb, and all the ports are smooth and well finished.

On the trail, the Montesa powerplant performs as well as its quality construction implies it should. Power is crisp and comes on fast in response to the throttle. Wheelies over logs or whoops or just for fun simply require a snap of the wrist in first, second or third gear. Clutch actuation, however, is stiff and immediately tiring. On the positive side, clutch fade is never a problem, and the gearbox requires clutching only for starting out and for hard downshifts.

The upper gear ratios are ill matched to enduro riding. First through fourth are well spaced and useful, and fourth is good for 50 miles per hour without straining the engine. And that's the problem: fifth and sixth are practically non-functional. Fire-road berserkos will love the top cogs, but sane people consider the 360H a four-speed machine. The fact that fourth, fifth and sixth are overdrives (0.941:1, 0.789:1 and 0.650:1) underscores the situation.

Montesa research and development people, having appraised the state of two-stroke technology and electing to stay with the basics, have presented an engine that's close to ideal. But quandaries and confusion hang over the 360H's chassis and suspension. As noted, there is an abundance of low-cost, trick, functional items. But the frame design and suspension units are halfway measures. Through either a lack of funds, an unwillingness to raise the price of the machine, or a simple misreading of the market and the competition, the 360H does not succeed in the handling department.

As with the engine, the major changes to the frame came in the 1977 model year when the single-downtube unit was replaced by a double-downtube design, and the laid-down shocks were moved to the forward-mount position. The 360H frame is still made of cold-drawn steel tubing, which provides as much rigidity as before. However, Montesa has tried to get maximum rear wheel travel by simply moving the shocks forward, and their method has yielded mixed results. To get the shock mounts positioned correctly and still allow room for an air cleaner somewhere behind the carburettor, the designers had to bend the tube which extends from the top of the shock to the rear of the engine.

All the minor features function well. The triple clamps mount on tapered roller bearings, and the swing arm rides on bronze bushings which have easily accessible lubrication points. Welded to the bottom frame tubes on each side of the engine are case guards; the right one, though, occasionally interferes with the rider's boot as he brakes. A centerstand, the lowest point of ground clearance (10.5 inches), is useful when performing routine maintenance or fixing flat tires.

Riding in the woods, the Montesa rider appreciates the basic frame geometry and seating position. The 29.5-degree head angle provides precise steering and—even though the 360H has a longish 57-inch wheelbase—the bike reacts quickly and consistently to body English. Part of the natural feeling of the Montesa's ride must be attributed to the distribution of the bike's 276-pound wet weight, which lets the rider throw the machine around even though its weight is average when compared with the 279-pound IT400 or the 260-pound KTM 400. In tight woods, the rider can point the Enduro between trees or around rocks and feel confident the bike will hold its course. The Pirelli front tire, however, blemishes the complexion of the Montesa's steering—it washes out on hard surfaces, soft surfaces and anything in between. About the only good thing about it is that it's poor consistently.

In cross-country use also, the 360H chassis performs well. Slides can be indulged in with safety and confidence. Peg clearance-12.5 inches—keeps the rider from worrying about rocks or stumps shortening his feet. The 35-inch seat height is the norm for an off-road bike, and it didn't pose any unusual problems for our five-foot, ten-inch test riders.

Though the basic chassis is satisfactory, the 7.8-inch, center-axle fork and Telesco shocks present a variety of classic suspension ills. In the woods and cross-country both, the fork locks up in normal use. Especially coming down from a wheelie or off a jump, the fork simply would not compress more than what felt like a couple of inches. Over smooth ground, or over large ruts or logs, it worked adequately. But since the owner, even if he solved the damping problem, would still be left with a 7.8-inch travel fork, the serious competitor would probably choose to buy an aftermarket fork.

The rear suspension units present a different problem: they collapse. In woods riding, hitting a large root or trunk bottoms them out, and in cross-country terrain, a series of even moderate-size whoops gets the bike pogoing and bouncing in all directions. Since the shocks feel firm over smooth ground, indications are that their problem is more complicated than an incorrect spring rate.

Both front and rear brakes work satisfactorily in normal riding. A full-floating rear brake, though, would provide a more precise feel when braking over rough ground or down hills. One Cycle test rider, moreover, had a rude surprise waiting for him the first time he crossed a stream: he found himself negotiating the next turn that came up at a far higher rate of speed than anticipated. Both brakes faded terribly, even though the water crossing was only a foot deep and 30 feet across. Just to double-check, he rode up the stream about 100 yards, duplicating a situation enduro riders find themselves in regularly. Exiting the stream he stood on the rear brake pedal, pulled in the front brake lever until his knuckles were white, and motored down the trail unimpeded.

In the detail department, Montesa has remained consistent in their approach to the 360H's design by mixing innovative items with outmoded ones. The engine has a clever press-fit rubber countershaft sprocket cover, necessary to allow quick access to the sprocket. Very closely surrounding that gear is a case guard to prevent damage in the event of chain breakage. Even though the centers of the countershaft and -the swing-arm pivot are 5.3 inches apart, chain adjustment and tracking are not problems.

Chassis detail components do not reflect the careful planning obviously devoted to the engine. The rear brake cable rubs against the right rear passenger peg. Even with the peg removed, the cable rests against the bottom shock mount, and routing the cable through the mount does not cure the problem. Fibreglass is used for the gas tank and side number plates, and tiny cracks appeared in the plates mounting points by the end of the test. A squeaky, ineffective horn is supplied—we hope only in order to satisfy some rule somewhere. A metal rock guard protects the headlight, which is adequate for nighttime plonking but not for competition. At first sit, the seat feels too firm, but it is actually quite comfortable; the buddy strap, though, is obtrusive. Wide, effective fenders take care of all mud-slinging. The beneficial result of the odd bends in the frame is an easily accessible, large, oiled foam air cleaner; a rubber-metal attachment secures the cleaner for extra-quick removal.

Montesa is obviously willing to experiment with their machines and create some trends of their own. For the most part, their innovative items are functional as well as imaginative. But the research and development staff people are going to have to exhibit more insight when differentiating between trick-and-useless and trendy-but-functional concepts. If the R & D men have done the best possible within a fixed budget and the responsibility for the 360 H's outdated suspension lies with the factory's management, then someone is going to have to decide to make a full-scale effort with the Enduro, or be left with a non-competitive machine. Trendiness notwithstanding, the 360H's clever and useful detail work does not offset its lack of functional—albeit trick—major components.■