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Best U-Locks

By: Saundra Latham on July 11, 2017

U-locks are the best defense against bike theft

While no bike lock is impenetrable, a top-rated U-lock can provide substantial protection. U-locks, which are also called D-locks, are tops on experts' lists of the best bike locks, and many thieves will leave a bike secured with a U-lock in favor of easier targets.

If you live in a higher-crime area and need serious security for your bike, reviewers say it's hard to do better than the Kryptonite New York Fahgettaboudit Mini (Est. $90). OutdoorGearLab.com's Rylee Sweeney and Ross Robinson call it "hands down the toughest bike lock we tested." Experts like the Fahgettaboudit's 18mm hardened steel shackle, which is slightly thicker than several comparable models and helps the lock resist attacks from bolt cutters and hacksaws. The center keyway adds a level of protection as well; experts say these are tougher to attack than side-mounted keyways.

While reviewers say the lock provides top-notch protection, they disagree on ease of use. Weighing 4.5 pounds, the Fahgettaboudit Mini is heavy for a U-lock. At 3.25 by 6 inches, it's also smaller than others, and a few owners say that makes it difficult to secure anything but their bike frame. Others praise the small design, saying it's easier to transport and makes it difficult for a would-be thief to get a tool between the lock and post. If the lock is too small for your wheels, consider the longer Kryptonite New York Standard U-lock (Est. $95), which some users prefer for its 4-by-8-inch size. The lock doesn't come with a mounting bracket, something that owners say makes transporting it more difficult.

The Fahgettaboudit Mini comes with three keys, one of which has a light. Owners appreciate additional features such as a protective vinyl coating and sliding dust cover. You can register for up to $5,000 of anti-theft protection from Kryptonite online within about a month of purchase. This coverage is beefier than most, but many say it's more trouble than it's worth since pieces of the broken lock must be sent to Kryptonite as "proof of lock failure" -- and many thieves don't leave evidence behind. 

If the weight of the Fahgettaboudit Mini is a deal-breaker for you, one alternative that has created a lot of buzz lately is the sleek TiGr Mini (Est. $100). Made of lightweight titanium, this triangular-shaped lock weighs in at a measly .9 pounds even though it's slightly larger than the much heavier Fahgettaboudit Mini at 4 by 7 inches. If that's not enough space, the more rectangular TiGr Mini+ (Est. $135) is 4 by 8 inches.

GearJunkie.com's Stephen Regenold says the TiGr mini is a tight fit around a bike wheel, frame, and post, though that helps bolster its security. In his hacksaw test, he compromises the lock in about five minutes, but notes that would be hard to do when it's secured. He also consulted locksmiths who were impressed with the disc-based locking mechanism. The Sweethome.com's Duncan Niederlitz is less complimentary, pointing out a weak point between the shackle and lock that he says makes it too vulnerable to bolt cutters. As experts with Sports Illustrated note, however, no lock is impenetrable, and they seem to think this one offers pretty good security for the increased portability.

On ease of use, though, it's hard to beat the TiGr, which aside from its weight comes with a mounting clip that reviewers say keeps their locks secure during transit. There is a PVC coating on the bow to lessen the risk of nasty bike-frame scratches, and the push-button lock mechanism means you can secure the TiGr without needing to fumble with the two included keys. There is no anti-theft protection.

If budget is a bigger consideration but you still need a relatively robust U-lock, the Abus U-Mini 40 (Est. $65) is a small but tough U-lock that won't break the bank. It has a 14mm double-bolted hardened steel shackle, which is a bit thinner than the one on the Fahgettaboudit Mini.

With a shackle that's roughly 3 by 5.5 inches, the U-Mini is slightly smaller than the already-small Fahgettaboudit Mini and TiGr mini. For that reason, some reviewers recommend it as a secondary lock, but many others have no problem using it as their primary lock. The 2.2-pound U-Mini is also roughly half the weight of the Fahgettaboudit Mini, making it a stronger contender for anyone who doesn't want to be weighed down by their bike lock, but can't stomach the premium price of the TiGr. Reviewers note that no mounting bracket is provided, and they say that's a feature that they miss.

The ergonomic U-Mini has "soft touch" housing to prevent paint damage to bikes, and reviewers say that also keeps the lock from getting damaged during drops. It comes with four keys and is available in red or yellow. Abus does not appear to offer an anti-theft protection plan.

Experts often recommend using a U-lock with another lock in order to keep both your frame and wheels safe. One well-reviewed combination is the Kryptonite Series 2 Standard (Est. $40) package, which comes with a 13mm hardened steel shackle U-lock and a 4-foot double-loop KryptoLok cable. However, a handful of reviewers say this lock has been defeated by bolt cutters -- if you're in a high-theft area, you may want to upgrade to the heavier-duty Kryptonite Evolution Mini-7 U-lock with 4-Foot Flex (Est. $65), which testers at The Sweethome recommend for its much harder steel shackle, or pair a cable of your choice with the Fahgettaboudit Mini.

At 4 by 9 inches, the Series 2 U-lock is generous enough to protect beefier bike frames, but still squeaks in at about 3.5 pounds -- lighter than the Fahgettaboudit Mini. If that's too big, you can pick up the Kryptonite Series 2 Mini package (Est. $40) which pairs the same cable with a 3.25-by-7-inch U-lock. The package also comes with a U-lock mount.

The Series 2 U-lock has a protective vinyl coating and comes with two keys. Some reviewers do say that the lock isn't smooth to operate and requires too much fiddling. The U-lock also has anti-rattle bumpers to reduce noise while riding. You can register for up to $1,750 of anti-theft protection from Kryptonite online within a month of purchase, but Kryptonite will require you to send in the broken U-lock, which isn't always possible. The coverage does not extend to the cable.

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