Before you buy a lock you need to decide.
- how much security you want/need
- how much weight you're willing to carry
- how much space the lock will take up
- how much convenience you want
- how much money you're willing to spend
There are tradeoffs. The most secure lock is going to weigh a lot and cost a lot of money.
The Master Lock
websites give a good idea of what is available. Both websites rate the locks in terms of the security they provide, and both companies offer guarantees on their better locks.
Kryptonite's Lock-up tips
are good, especially tip #3: Lock in a visible and well-lit area.
How much security you need will depend mainly on where you lock your bike and the value of the bike. For high security, there's Kryptonite's New York Fahgettaboutit.
Six-sided (11mm) hexagonal chain links made of triple heat-treated boron manganese steel. Through-hardened 1/2" (13mm) Kryptonium(TM)Steel shackle
The Fahgettaboutit weighs 8.4 pounds and I'm sure it's pricey. You're probably better off buying a u-lock. (like the New York Model 3000, which only weighs 3.7 pounds)
Cable locks offer moderate security. Even Kryptonite's biggest, best (and shortest) cable (3/4 x 30 inch) has the warning:
WARNING: Cables are deterrents and should be used with a U-lock for greater security.
But let's be realistic. A good cable lock is adequate in many circumstances. How much security do you need/want?
Cables are considerably lighter, less bulky and easier to use than u-locks. And a cable lock won't take up a lot of space on the bike the way a u-lock does. I can wrap a cable lock around the seat post and have room left for water bottles and pumps inside the triangle. I use a 1/2 x 6 foot locking cable most of the time, but I'm careful where I park and lock my bike. (and I don't have any real expensive bikes) A half inch cable requires tools to cut. I'd stay away from the smaller cables, though. A 3/8 or smaller cable is fairly easy to cut.
If you want security and are willing to carry a heavier and more bulky lock (or, perhaps, leave it at your destination), a u-lock is probably the way to go. U-locks are also harder to use and are less versatile in terms of what you can lock them to. And they need to fit the bike. And, by themselves, they won't lock the front wheel, so you need a cable, too.
Master offers 3, 5 and 6 ton u-locks, all with guarantees, and Kryptonite has a considerably wider choice of u-locks than that, with guarantees on the better ones. I'd get one that has a guarantee. The lighter u-locks probably aren't a whole lot more secure than a good cable lock.
Master also has a couple of new products, including street cuffs
. I'm not familiar with street cuffs, but they look interesting.
The point of all locks is to slow a potential thief down. The better the lock, the more time and effort required to defeat it. No matter what lock you put on anything, if someone really
wants to steal it, has the time, and knows what they're doing, they can steal it. The good news is that a lot of potential thiefs don't know what they're doing. (I used to be a locksmith; that's what I learned