Bicycle security grading cards for Windsor and Maidenhead
Bicycles in a Berkshire borough will be graded with a hidden mark according to how securely they are locked to tackle a rise in thefts.
Police figures for Windsor and Maidenhead show 456 bicycles were stolen between April 2010 and 2011, compared with 427 the previous year.
Wardens and police community safety officers will now carry grading cards to stick to parked bicycles.
Brian Martin from the council said the cards would be a "wake-up call".
Mr Martin, a community safety manager, said that bicycles should be "locked in at least two places" with the wheels properly secured.
"A wheel for an expensive bike these days can cost about £500," he said.
He added that the grading would be obscured from view and that it would not help thieves determine which bicycle is easier to steal.
"We don't expect thieves to go along and look at every grading," he said.
"We won't display the level of security a bike has got".
The council has set up a deal with local bicycle shops to offer cyclists with grading cards a discount on locks.