The first ads for Whizzer motor kits appeared in 1939, and what American boy could possibly resist? For only $54.95 you could convert your bicycle into a full-fledged motorbike. Think of the fun, the admiring glances, the wind in your hair as you purred down Main Street!

So you sent for the kit, and four weeks later a big cardboard box came in the mail. Tucked neatly inside were a l3/s-horsepower one-lung engine; a three-point spring-steel universal engine mount; assorted pulleys, rollers, and belts for the drive train; levers and cables for the accelerator and compression release; a teardrop-shaped fuel tank; plus all the hardware and decals you needed.

In Whizzer’s early years the company behind this magic was BreeneTaylor Engineering of Los Angeles. Breene-Taylor wasn’t the first to dream up the bicycle motor kit, but it succeeded where others had failed. The constant barrage of ads was partly responsible for its success; another reason was the name, which capitalized on the popularity of Byron R. (“Whizzer”) White, a running back at the University of Colorado who later served on the U.S. Supreme Court.

All Whizzer engines from 1939 through 1969 displaced 8.45 cubic inches. All were one-cylinder, four-stroke, L-head, and air-cooled. Early blocks were cast iron and used big roller main bearings. By 1946 the improved Model H had an aluminum head and caged roller mains. Horsepower rose to 2½ in 1943 and 3 in 1949.

Pre-war Whizzers came with a primitive drive system that transferred power to a series of rollers. The final roller pressed against the bicycle’s rear tire tread. Later drive trains eliminated the rollers and used belts. Although some postwar Whizzers offered kick starters, you normally started the engine by pedaling while holding open the compression release. When you reached 5 miles an hour, you closed the release, and the engine fired. Whizzer ads promised fuel economy of “6 to 10 miles to the penny,” meaning about 125 miles per gallon. In good tune a Whizzer could cruise happily at 35 miles per hour, topping out at 40.

Early Whizzer engines were notoriously unreliable, but just after Pearl Harbor Breene-Taylor sold its business to an entrepreneur named Dietrich Kohlsaat. Kohlsaat immediately ordered the engine redesigned, and subsequent models enjoyed a rising reputation for stamina and durability.

After the United States entered World War II, raw materials, especially aluminum, iron, and rubber, became increasingly hard to get. Whizzer was able to continue building motor kits by convincing the government that war workers would require economical transport to get to and from their jobs. Anyone buying a Whizzer during the war needed certification that he or she was engaged in vital defense work.

Immediately after the war Whizzer sales skyrocketed. During the carstarved postwar years, 1946-1951, the Whizzer factory, now in Pontiac, Michigan, shipped more than a thousand kits a week and had 3,500 franchised dealers. Pent-up demand for new cars and the resulting high prices of used ones gave Whizzer a huge boost.

Then came the crash. By 1952, auto production had caught up with postwar demand, which meant that usedcar prices fell again. A teen-ager could now buy a Model A Ford for SSOSSO, considerably less than the cost of a $100 Whizzer kit. Competition also arrived from motorscooters like the Cushman and the inexpensive, lightweight Italian Vespa and Lambretta. And after the war most states restricted driver’s licenses (required even for motorbikes) to those over sixteen, eliminating Whizzer’s youth market.

By the mid-1950s Whizzer was trying desperately to stay in business. In 1948 Kohlsaat had arranged with Schwinn to produce and sell complete motorized bicycles. (Schwinn, of course, had a huge dealer network.) The Schwinn/Whizzer motorbike used a heavy-duty boy’s bicycle frame with Whizzer power and sold for about twice as much as an unmotorized Schwinn. The strategy didn’t work. Eventually Whizzer diversified to building storm windows and kitchen utensils; in 1969 the company closed its doors.

Today there’s a rekindled interest in Whizzers. Enthusiasts stage annual Whiz-Ins; at a recent one in California, boxed kits were selling for $2,000. Asking prices for fully restored Whizzer bikes ranged up to $5,000. A California firm now produces and sells a replica of the Whizzer motor kit, and many individual Whizzer parts and accessories are also being manufactured again. What was once a makeshift solution for teen-agers is now an expensive hobby for grown-ups.