Locks are rated by how long they resist attack, and a lock that is easy to carry is a lock you will actually bring.
Verdict
A hardened U-lock gives the most resistance per pound and per pound sterling, which is why it remains the standard recommendation. A folding lock gives up some of that in exchange for reaching around objects a U-lock will not fit and packing flat on the frame. The best lock is the one you carry, and neither of them helps if the bike is locked badly.
No lock is unbreakable. Security ratings such as Sold Secure and ART describe how long a lock resists a determined attack with tools, and the practical aim is to make your bike a worse target than the one next to it and to take longer than a thief is willing to spend in public.
The other half is technique, and it matters as much as the hardware. A very good lock through only the front wheel protects a front wheel.
~$129.95
Check Backcountry → Check Kryptonite Evolution U-lock Price~$95.40
Check Backcountry → Check ABUS Bordo 6000C folding lock Price| Kryptonite Evolution U-lock | ABUS Bordo 6000C folding lock | |
|---|---|---|
| Attack resistance | Highest for the weight | High, more links to attack |
| Reach | Limited by shackle size | Wraps wider objects |
| Carrying | Frame bracket or bag | Folds flat, frame mount |
| Weight | Heavy | Heavy |
| Covers wheels | Needs a cable or second lock | Sometimes reaches both |
| Typical price | About $130 | About $95 |
You lock up in a city, leave the bike for hours, or the bike is worth stealing. A hardened steel shackle is the hardest thing at this price for a thief to defeat quietly, and a smaller shackle is better than a larger one because it leaves less room for leverage. Pair it with a cable or a second lock for the wheels, and mount it on the frame so you never leave it at home.
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You lock to a variety of objects, including ones a U-lock will not fit around, or you want something that packs flat. A good folding lock reaches around wide posts, railings and awkward stands, which in practice sometimes means the difference between locking to something solid and locking to something convenient. It has more joints to attack, which is the trade you are making.
Check Backcountry → Check ABUS Bordo 6000C folding lock on Amazon
Lock the frame to something immovable, not just a wheel, and check that whatever you are locking to cannot be lifted over or unbolted. Fill the inside of the lock so there is no room for leverage. Keep the lock off the ground, since a lock on the pavement can be smashed against it. Secure both wheels with a second lock or a cable, remove lights and computers, and photograph the bike and record its serial number, since police recover bikes they cannot return without one.
A hardened steel U-lock with a high independent security rating, such as Sold Secure Gold or ART, is generally the best resistance for the weight and price. No lock is unbreakable; ratings describe how long the lock resists a determined attack with tools.
Good ones are rated well and are considerably better than a cable lock. They have more joints and rivets than a U-lock, which is where an attack is directed. Their advantage is reach and packability, which matters if it means you carry a proper lock instead of a light one.
In a city, yes. Two locks of different types force a thief to carry and use two sets of tools, which is a meaningful deterrent, and a second lock covers the wheels that the first one does not. A common arrangement is a U-lock through the frame and rear wheel plus a second lock or cable for the front.
Often, and usually with conditions about the lock's security rating and how the bike was secured. Policies frequently require a specific rating and proof of purchase for both bike and lock. Read the conditions before relying on it, and keep receipts and the serial number.
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these units side by side. Confirm current prices and specifications before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.