Kryptonite Kryptolok Series 2 vs New York Legend 1515

This u-lock can work well in low-risk situations, or as a secondary lock to secure your wheels or seat.

There is an included cable with the U Lock, that allows you to secure the other bike wheel (not locked with the U Lock itself), or the seat. This is great for city riders who have quick release wheels, as an unlocked wheel makes for easy theft.

There is an included mount for the U Lock, which allows for one to easily transport the lock with the bike with no further equipment needed.

The New York Legend 1515 chain is very heavy (15+lb). It's so heavy that it would be impractical to take it with you on a daily basis, but it's great to be used as a stationary lock at, for example, home or work.

With a chain thickness of 15mm it's impossible to damage this lock with manual bolt cutters. If the thief is really determined, they'd have to use power tools, and it's hard not to notice someone sawing away, sparks flying at a bike chain. At the very least, this lock will buy you plenty of time, or attract lots of attention to the thief brave enough to attempt to break it.