The Motorbike Archives

But although the MX doesn't make it as a winning moto-crosser, it is definitely not a failure as a motorcycle. No indeed. As a long-distance woods or desert bike for the experienced rider who likes to go faster than the regular enduro machines will carry him, without sacrificing low-end torque, the MX is the answer.

Understand, the MX is not for the average trail rider; it doesn't have lights, so it's not street-legal, and you can't ride it at night. And for what it is, the bike is expensive—$1300, Port of Entry, to which you then add freight and setup and taxes and whatever else the dealer wants to tack on. But for the rider who really likes to cover a lot of bad territory at one stretch, who likes to cover territory fast, who wants enough usable torque to get him out of almost any kind of trouble he can get himself into, who wants a bike that won't throw him off and stomp him when he gets tired (thus, careless) toward the end of a long day's ride—for that rider, the 500cc single-cylinder MX is the perfect (and at present, only) big bike that will do the job.

At 263 lbs. with half a tank of gas, the MX is light. .And even though it is tall, with a saddle height of 33 inches, the bike feels light and maneuverable—more so than any of the mass-production 360cc enduro machines.

The seating position on the MX is excellent. The 3/4-length saddle itself is well-padded, but the sides fall away at right angles, and the seam will rub your thighs after several hours in the saddle.

But the gas tank is the real offender. It's so skinny that you can't grip it with your knees, or hang one knee under it when broadsliding fast corners. Worse, you can slide forward on it all too easily, and hurt yourself. You're faced with the choice of buying extra-strong, (ah, protection,) or a better gas tank. Most riders will prefer to buy a bigger tank, since the standard tanks holds only 11/4 gallons of gas, making it useless for the kind of riding that the bike does best.

If you don't know how to fire up the MX, the bike will bite you. The trick is to use the compression release, and little or no throttle. What you do is tickle the carb, leave the throttle alone, pull the compression release, and kick it through a few times to get the bike used to the idea. Then you pump up the kickstarter, pull the release, give it little or no throttle, and kick like hell, letting fly the release on the downward stroke. That way the bike will fire on the first serious kick about nine times out of ten, and your ankle and shin will remain intact.

The big single churns to life with a lusty chug-chug sound, more than a little reminiscent of a John Deere farm tractor. It's a big, thundering sound, but it doesn't bother your ears all that much. Compared to the high frequency bleat of a big two stroke, the B50's mellow baritone is music to the ears of many. There is a large contingent of Gold Star and Matchless-AJS and Ariel and Velocette veterans lurking around, which just seemed to quit dirt riding when those great galumphing monsters ceased being made. To the man, of those old single lovers we know, this group feels very close to the MX. Many of them even express interest in starting to ride again. And it's the sound that first attracted the veterans to the B50.

Lightness, and the resulting good handling, reinforced the emotions started by the sound. Experienced desert rats tell us that they are able to ride farther and faster, with less fatigue, over routes that they rode in the past on their older, heavier singles.

Contributing greatly to the newfound riding ease is the careful matching of the MX's power to its gearbox.

The unit-construction engine has a four-speed gearbox, which is fine, because it just doesn't need five speeds. The bike doesn't have a tachometer, and it doesn't need one of those either. It doesn't seem to matter how many rpm the engine happens to be turning—if you want to go faster, you just feed it some more throttle, and the engine responds, instantly. Anywhere. From idle. Because even though the MX engine is tuned to deliver more horsepower than the enduro version, it has so much bottom-end torque to spare that it will still thump along at ridiculously low revs, so that you can play tractor in gullies and on big rocks.

The engine really gets on the cam at about 3500 rpm, and it gets from there to 7000 rpm in a big hurry. To go up through the gears, you just wind it up tight and nudge the shift lever. The clutch works fine, but you don't need it, because after the first few hours of run-in, the gearbox works like vase-line.

The steering on the MX is slow and stable. If anything, it is too stable, because the bike doesn't want to turn very quickly. It understeers, wanting to keep going straight when you take it into a fast corner. But the bike isn't sneaky about its cornering characteristics; it lets you know right away what its scene is, and you quickly learn to crowd a little harder in the corners. You either lean it in deeper, or you hang the tail out and broadslide it. But in deep sand or on slippery surfaces, you just ride along with a great big smile on your face, because you know that the bike isn't going to do anything sudden. The machine's steering doesn't feel heavy—just slow. After the first day of riding it, you adapt automatically to the cornering requirements of the bike.

The MX is much easier to ride than the faster motocross machines. For example, a good motocross rider who is concentrating can take a 400 Husky—with its extra power and fast steering—around a motocross course far quicker than he could on an MX. But the experienced woods or desert rider who doesn't happen to be a motocross racer could probably take the MX around a motocross course faster than he could the Husky.►