Thieves are always on the prowl for easy-to-steal unlocked bikes on campus. But police say that with fewer people around over break, thieves take the opportunity to go after locked bikes as well.

Students reported to Penn State University police Monday that a $350 bike was stolen from a rack near Pennypacker Hall and a $250 bike was stolen from a rack near Simmons Hall. On Sunday, a student reported his $230 bike was stolen from a rack near Hartranft Hall.

All of the bikes were locked to the racks, police said.

Sgt. Don Hazel said the thefts were probably not related, but bikes often get stolen over breaks because there are so few people on campus.

"We can't post somebody at every bike rack," he said. "It's so easy to traverse campus and not really draw suspicion to yourself."

Cheaper steel cable locks can be broken with a small set of cutters, but even more expensive "U" locks can be broken by freezing the lock and then breaking it, Hazel said.

However, David Cicero Bevacqua, a local biker, said he tested out trying to break a lock using liquid nitrogen without success.

"It didn't help at all," he said. "I don't know what you have to do."

Bevacqua said another tactic for opening U-locks is putting a tire jack in the lock and attempting to force it open.

Police sometimes recover stolen bikes on campus, but thieves also try to sell stolen bike parts or use them to repair their own bikes, Hazel said.

He said that businesses are supposed to verify that bike parts are not stolen.

And just because a bike is cheap doesn't mean thieves will ignore it, Hazel said.

"I've seen people take a $50 bike," he said.

William Tate, a member of the Penn State Cycling Club, said high-quality locks can be bought for between $30 and $40.

"What we generally tell people is to buy a good lock," he said. "The real cheap ones are pretty easy to break or cut."

"The more expensive the lock and the better constructed it is, the harder it is to break," he added.

Tate said one or two secured bikes are stolen from cycling club members each semester.

He said he always locked up his bike when he rode it on campus, but now that he rides a more expensive racing bike, he keeps it in his apartment.

"I wouldn't really want to keep it out on the street unless I absolutely had to," he said.

Bevacqua said he always uses a U-lock in urban areas, but he usually uses a cable lock or keeps the bike at his house when in State College.

Police recommend storing bikes in rooms over break. They also recommend registering a bike because it proves ownership if the bike gets stolen.

And of course, make sure the lock is attached to both the bike and the bike rack.

Hazel said he once found a stolen bike locked to a bike rack -- with the old lock still on the bike.