Kryptonite New York 1275 Heavy Duty 2.5 Feet Bike Chain Lock - Sold Secure Gold Rated Anti-Theft Bicycle Lock with Evolution Disc Lock & Keys for E-Bike, Motorcycle, Scooter - Perfect for Urban Commuting & Parking Security

This is an excellent lock. But if you're having trouble opening the lock and force the key, the key WILL break.Kryptonite will refund your locksmith bill AND replace your lock - that's why this review gets 5 stars instead of 4.Chain:Pros: Huge, but not too long. Heavy, but not too heavy. Intimidating enough that it will hopefully turn away any sorry sops with bolt cutters before they even try. Jacketed in a sturdy sleeve to avoid the pinchy-pinchy finger effect. Also, this chain is just downright attractive.Cons: Ok - so it's a little heavier then what's comfortable for a small or unfit person to move around, but if you bike a lot you've gotta be fit (haha not me), right? And it can be a little too short if you're stuck locking up to a thick pole or column.Lock:Pros: Good sturdy lock. Never had mine picked.Cons: If you don't listen to instructions and force the key, it WILL break, and it's INCREDIBLY hard to fish out, if not impossible - depends on how the key breaks. If the key resists, stick a screwdriver or something in the lock to re-align the tumblers and try again. Once more, DO NOT force the key! It will break!