Without any doubt the most secure portable bike lock available today is Kryptonite Fahgettaboudit. With a 18 mm shackle, it’s completely bolt-cutter proof and best u lock for bikes. The only way this shackle can be cut is with an angle grinder because it’s made from a super high quality MAX performance steel, it will take longer than any other bike lock. However, if you’re high risk: this is a fantastic bike lock.
Incredibly secure, it’s as close to unbreakable as you’ll get. And it achieves this while still being portable. All in all: the best choice if you need the very strongest portable bike lock.
And don’t forget: it’s double bolted (locking on both sides of the shackle), so it needs to be cut twice to open it up!
This extraordinarily high level of security is reflected in the ratings from the independent lock testers. Not only does it get Sold Secure Bicycle Gold. It also gets Sold Secure Motorcycle Gold which requires a higher level of security again. And it also gets 4/5 stars from ART.
But if it’s too heavy, too small, or too expensive then there are plenty of alternative best bicycle lock 2021 – 2022 ….