Anyone who is determined to rip off your bicycle probably can get away wtih it. About the best you can do is to make stealing it so long and hard a process that the thief will get spooked or winded.

Most padlock-and-chain devices are junk that cut like butter with compound bolt shears, the bikenapper's standard tool. Citadel and Krytonite locks, U-shaped devices that shackle your bike directly to a parking meter or pole, are vitually impervious to the tools and methods used by thieves. If you lock your bike properly with more of them, and conform to the other requirements of the guarantee, you can collect up $200 worth of new bicycle if it's stolen.

Larry Reilly, bicycle coordinatory for New York City's Department of Transportation, credits this type of lock with reducing bicycle thefts there by more than 30 percent. "Anybody who doesn't use this type of locking device is just asking for trouble," he said.

There are two kinds of bike thieves, those who go out and steal something -- anything -- because there's nothing good on television, and those who do it for a living. The amateurs can often be thwarted by a modicum of common sense; it's the other guys who have made the lock, chain and cable market big business.

There are at least 65 brands of padlocks, chains cables, etc., sold by "bicycle locks," some of them with 20 or more alternate models. Some are about as difficult to open as a "childproof" aspirin bottle; many substantially stronger padlocks are sold with lightweight chains or cables not a whole lot sturdier than coat hanger wire. The trick is to acquire a combination of padlock and chain or cable, neither of which is easy prey for the thief's bolt cutters.

Ray Seakan, president of the Citadel company, recalls buying his first bike "years back" and going into the hardware store for some quarter-inch, hardened-steel chain to safeguard it. It alarmed him when the shopkeeper took out his bolt cutters and calmly looped off the asked-for length.

I am not aware of a chain or cable truly "bolt-cutter-proof," depending on the size of tool used against it. Pressed to name a chain by would trust if neither the Citadel nor Kryptonite were available, Seakan and Michael Zanem, who runs the Krypotonite company, said a 38/88-inch or larger "boron inoculated" chain is the next best alternative, providing an equally impregnable padlock is used.

When asked to name a good padlock, Seakan said, "an American with a 73/816th shackle," American being the brand name. Zane said the stainless steel, laster-welded Abus was excellent, and the Medeco, manufactured in Virginia, even better. "But it costs $40," he added.

A 93/832nds-inch boron-inoculated chain can almost defeat a set of bolt cutters four feet long. It is difficult for someone to look nonchalant with something that big up his sleeve and to the thief, I'd say the boron chain was a safe bet. Four feet of it, with an Abus padlock on one end, weighs 3 1/2 pounds and cost about $30. Six feet of it, five pounds at $35. You can get a $200 guarantee with that combination, similar to that offered by Citadel and Kryptonite.

And what of the lesser padlocks, chains and cables? It depends on how comfortable you can be knowing their vulnerability to medium-size or smaller bolt cutters, or even to pliers. Neither the Citadel nor the Kryptonite, I'm assure, will yield to even the largest bolt cutter.

There are more bikes stolen in big metropolitan areas than in smaller cities, and more from schoolyards than anywhere else in town. So if you park you bike on a big city campus, according to the surveys, you're in the No. 1 target area. The newer and shinier the bike, the more apt it is to be stolen.

If you can, lock up where anyone meddling with it can easily be observed. If the front wheel has a levered, "quick-release" hub, remove the wheel and lock it to the frame and rear wheel. Be certain you're locking the frame, too, not just the wheels, to something immovable. If you're using a chain, pass it around your "anchor," through both wheels and the frame, too, with the chain as high as possible off the ground.

To aid recovery, if it is stolen, police recommend registering it or at least recording the serial number. A color photograph of it may help establish ownership. The repainting of bicycles isn't as common as repainting stolen cars. Many stolen bikes are quickly sold for a few bucks a hundred yards from the severed cable.

Randy Kirk, a Southern California distributor of locks, chains and cables, promotes what he refers to as "the good neighbor policy." Lock up your bike better than the one next to you, and they'll steal your neighbor's bike instead. That doesn't sound very neighborly, but it makes sense.

"Selling locks is a repeat business," Kirk said. "Someone buying his or her first bike often buys a cheap padlock and cable. The good locks are sold with the second bike, after the first one had been stolen."