Best Chain Bike Locks

Bicycle chains are strongest, but sacrifice portability

Bike chains generally don't fend off attacks as well as U-locks do, and they're heavier and bulkier to carry. Yet they look imposing and tough, and experts say that chain locks are a good option for securing several bikes together. Since none of the top-rated chains are particularly convenient to ride with, many reviewers say if you're getting a chain for situations where it doesn't need to be carried, it ought to be the toughest.

Appearances can be deceiving, however: Many chain locks can be broken with a pair of bolt cutters. While the OnGuard Beast Chain Lock (Est. $80) gets the best reviews, the Kryptonite New York Fahgettaboudit Chain (*Est. $90 and up) is also a popular choice. The OnGuard Beast is burlier and extremely heavy at nearly 10 pounds. It's not ride-friendly, but it offers good security for home use or to leave someplace you visit often.

In a 2009 Men's Journal test, the OnGuard Beast receives the only perfect score for security, but it gets poor marks for usability due to its weight. Still, it took testers 25 minutes to break just one of its links with a power tool; even huge cutters borrowed from a nearby firehouse had little effect on this chain. It also rates highly at Buzzillions.com, where owners say it's extremely strong and durable, but again, heavy. Amazon.com posts are equally positive, with the same single complaint.

The OnGuard Beast Chain Lock has an advantage over standard chains: Its links are six-sided rather than tubular, making it harder for thieves with bolt cutters to get a good grip. OnGuard's $5,001 anti-theft protection plan is higher than many other models, but again, it's not applicable in New York State.

The Kryptonite New York Fahgettaboudit Chain is 3.25 feet long and weighs 8.5 pounds; a 5-foot length is also available. Kryptonite offers up to $3,500 in anti-theft protection. Many reviewers say the security of this chain lock is hard to beat. Warren Rossiter at BikeRadar.com says, "strength-wise, it's simply one of the best." Even with power tools, it took him nearly two minutes to get through just one chain link. In similar tests at BikeRadar.com, the chain held up for about a minute when attacked with power tools. Even so, most reviewers say the heftier OnGuard Beast offers more bang for your buck and a higher level of security in its anti-theft protection plan.