An Adams Morgan inventor is trying to lock up entrepreneurial success by helping cyclists lock up their bicycle pumps, tools, spare parts and other small valuables.

Mike Olshausen has invented the Bicycle Safe, a two-piece plastic box that splits down the middle and has openings at each end allowing it to be fitted around a bicycle frame tube and a bicycle pump attached to the tube. Included with the box are adapters to accommodate pumps of varying diameters and to permit attaching the box around brake cables.

The Bicycle Safe comes in three sizes. The largest is 4 1/4-by-3 1/2-by-3 inches. Besides the openings that allow the box to fit and lock around frame tubes, pumps and cables, the most interesting aspect is the way the two halves lock together: A threaded bolt attached to the inside of one half of the box engages a threaded shaft attached to the other half. The bolt is turned from the outside with a key to lock or unlock the box.

There are two smaller boxes. One locks a pump in place and can hold a few objects; the other serves mainly to secure the bicycle pump but also can hold something small, such as a folded up $5 bill.

Because the boxes can be attached to frame tubes leading from the handlebars to the seat, from the seat to the pedals and from the handlebars to the pedals, more than one can be used at a time.

Olshausen wants to license the right to manufacture the Bicycle Safes. He said that two of the four companies he has contacted have expressed interest. He was granted a patent for his invention on Sept. 4.

"I'm from Detroit, and I've seen a lot of companies and jobs go down the drain, and I'd like to see an American company" manufacture the Bicycle Safes, he said, adding that he will contact foreign companies only if no agreement can be reached with a U.S. firm.

Olshausen described himself as a free lance writer and editor who has other inventions, although this is the first he has patented. He said he has taught English, mathematics and other subjects as a substitute at Dunbar High School, is a licensed tour guide, is working with a client on a study of the Shiite Moslems and is writing a novel.

He said that he started biking seven years ago, "and it just occurred to me that it was odd that I just couldn't go into a store and buy something to solve the problem" of storing a bicycle pump and small objects when biking.

"The solution to the problem is simple, but the working out of it isn't," he said.

As for the potential market, Olshausen has done his homework. He has a securities analyst's report, an industry survey and newspaper clippings indicating that there were roughly 7,500 to 8,000 bicycle retailers in the United States in 1982, and that some 20.2 million of their customers made a total of $585 million in purchases that year.

Olshausen indicated that capturing even a sliver of this potential market could make his dream of success come true.