BMW R 69US

BMWs are very much different from the run-of-the-mill motorcycle, because they're built like an automobile. In fact, forget that they ride on two wheels, and they're more like a car than a bike.

Let's start with the engine. And that will tell you why the BMW is so like a car. Have you ever seen a Volkswagen engine out of the car? Try to visualize two of the cylinders missing, and all the cowling pulled off. The capacity of that engine would just about match the 600-cc. capacity of the BMW. This may not seem big by automotive standards, but at 7,000 r.p.m. it cranks out a very healthy 42 horsepower, and you've got to use a good grade of gasoline, as the compression ratio is 9.5:1.

The clutch is just like the one in a stick-shift automobile; it has a double-faced friction disk that rides on the flywheel, and a pressure plate. The gearbox is also similar. It forms an integral part of the engine housing, and internally looks very much like your automobile gearbox, too. Each gear ratio is derived from pairs of spur gears that remain continuously meshed during shifting, making for a smooth shift in every gear.

The rear drive also looks like a byproduct of automotive engineering. If you split your car's differential right down the center, you'd have exactly what you find on the BMW. You'd see a complete ring-and-pinion setup; even a shaft drive and universal joint going to the gearbox. As I said, the bike is more automobile than motorcycle.

It even rides almost like a car. The rear suspension is of the pivoted swinging-arm type. The pivot point attaches to the rear of the main section of the frame, and oil-damped shocks and rebound springs control wheel deflection. The front suspension is a modernized version of the old telescopic fork that BMW pioneered for motorcycles back in 1935. There are very few machines today that do not use this type of suspension. It's just two oil-damped hydraulic cylinders with a rebound spring on each one. The damping action is progressive, which means that the farther the suspension moves, either up or down, the stronger the action of the suspension.

BMW has an ace in the hole, too. Take any bike around, and I'd be willing to bet that you'd lucky to come up with five full inches of fork travel. BMW's has no less than 8 inches! I didn't really appreciate this suspension until I was riding through Louisiana in a driving rain. My speed was about 60, and as I rounded a sharp bend, what should I see but a large, wet mattress right in the middle of the road. I had my choice of sliding almost $2,000 worth of shiny motorcycle or trying to jump the mattress. I aimed for the middle of the mattress and punched it head on.

I've jumped competition bikes before, but this was really something out of the ordinary. The trick to jumping a motorcycle is to slide back on the seat for weight transfer, and then roll the throttle on, as you hit the jump, to keep the front wheel up in the air. I'll bet I was three or more feet in the air with a machine weighing in at 448 pounds. Since I'm not writing this from a hospital bed, you can

gather that I came down all right. To be truthful, the only thing that kept me out of the ditch was that fine front suspension. The frame of the bike, incidentally, is of the duplex cradle variety, and looks robust enough to support much more than its engine and a rider.

Taking on the weather. In Louisiana, it began to rain. By the time I entered Texas, the rain had turned to sleet and driving snow. I was even stopped once by the state police and told that tornado warnings were out and I would be proceeding at my own risk.