When the University Police started compiling bicycle theft statistics 14 months ago, they found that one of the worst places to park a bike was at the Grays Hall racks behind the police station.

Since that time, bicycle theft rates have dropped substantially. In the first quarter of this year, 44 per cent fewer bikes were stolen than in the same quarter of last year, and the theft rate at Grays has been cut in half.

A few years ago, students were content to lock their bikes with the not-very-reliable combination of chain and padlock. But thefts mushroomed along with the ten-speed bicycle craze, and students began removing their front wheel when they parked, buying heavier and heavier chains, and eventually looking for totally new kinds of locks.

Jeffrey S. Kahn, captain of the Universtiy Police, this week credited the force for some of the decrease in thefts. "We're making bike thefts a target," Kahn said. "We're doing something about it."

Kahn added that most bicycle thieves are juveniles and that the word gets out fast that Harvard isn't an easy place to steal bikes anymore.

But Lawrence J. Fennelly, a member of the University Police's crime prevention unit, said he wasn't sure why the rate has gone down. "It could be a combination of educational programs, increased patrol, or just luck," Fennelly said.

The police initiated their registration and engraving program last year. Since then over 600 students, faculty and employees have registered their bicycles.

But the biggest boon to law enforcers trying to cut theft rates has been the new trend in bicycle locks, spawned by the Kryptonite lock five years ago. Now the U-shaped locks account for 75 per cent of all locks sold by the Bicycle Exchange.

One of the major producers of U-shaped locks, KBL Corporation, reported yesterday that sales have increased tremendously over the past five years, including a 35 to 40 per cent jump in sales this year alone.

"There's an increased awareness about bike security," William DeSimone, assistant manager of the Bicycle Exchange, said yesterday. He added that customers started specifically asking for the U-shaped locks in the spring of 1975.

The University Police last year distributed reprints of the Consumer Reports study of bicycle locks and depicted a U-shaped lock in their "Lock Your Bike" posters. But the police have also stepped up their patrols in high bike-theft areas.

"If there are bicycle thefts three days in a row in the same area, plainclothesmen are sent there to watch it all day," Fennelly said.

The police have been recovering more stolen bicycles--about 100 last year--but since most have not been registered or reported stolen, Fennelly said, they are usually auctioned off by Phillips Brooks House.