The suspects targeted East Camden Middle School around 1:45 Friday morning.
They spent about 45 minutes inside the school before taking off with the stolen items.
Detectives say they made off with the school's supply of specialized bikes.
The bikes were used to help children learn to ride.
"I'm sad. The whole team is messed up," said Taylor Chambers, one of the program's participants.
In all, six mountain bikes, used as part of a summer cycling team, were stolen.
"Why steal our bikes? Our team loves our bikes. Why can't you go buy your own?" Taylor said.
Several computers and an overhead projector were also stolen from the school.
"Any time anything affects anybody in our community, especially juveniles in a school, it gets extra attention," said Capt. Gregory Carlin of the Camden County Police Department.
This is the second school theft in Camden in just over week.
Last Thursday, police say, someone broke into the Cramer School and stole several computers and electronics.
Anyone with information on theft or the identity of the suspects is urged to call Camden County Police at 856-757-7400.
Meanwhile Action Wheels in Deptford, New Jersey has set up a fund to help replace the bikes that were stolen.
For more information visit: http://www.actionwheels.com