This ludicrously chunky lock is claimed to be angle grinder-proof

Altor's SAF, a 6.25kg behemoth of a lock, is live now on Indiegogo

Altor SAF Lock in hands

Altor’s SAF is a ludicrously chunky 6.25kg behemoth of a lock which claims to be the world’s first U-lock that can withstand an attack from an angle grinder for more than 30 minutes. 

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Designed to be used when leaving a bike unattended for long periods of time, the lock is intended to be as secure as possible with absolutely no compromises made in the name of portability.

Altor SAF lock key-specs

  • Claimed to withstand over 30 minutes of attack from an angle grinder
  • Patented SAF Tech Shell enshrouds 14mm hardened steel shackle in 80mm cutter-clogging alloy sheath
  • Lock barrel secures shackle at either side of crossbar
  • Vinyl coating to protect frame
  • Claimed 6.25kg / 13.7lb weight
  • $299 per lock (international pricing TBC)

What makes this lock so secure?

U-locks (or D-locks, if you prefer) are the most secure type of bike lock, but increasingly powerful portable brushless angle grinders can cut through a typical shackle in seconds. 

Altor SAF Tech shell cutaway
The SAF Tech Shell is designed to clog and blunt angle cutter blades.

Best thought of as a shackle within another shackle, Altor’s patented SAF Tech Shell is an 80mm diameter semi-hollow alloy sheath that completely envelops the lock’s 14mm hardened steel inner core. This sheath is designed to clog up and blunt the cutting blades of an angle grinder. 

Even if you could cut through this layer — though Altor claims a typical portable angle grinder’s battery would run out before breaching the outer shell — its substantial 80mm diameter girth would mean that a regular 5-inch cutting blade wouldn’t be able to reach the steel core without butting up against the body of the grinder itself.

The lock is also built around what is said to be a “best-in-class eight-disc detainer locking mechanism” that is claimed to be highly resistant to lockpicking. 

This lock independently secures each side of the shackle, which means both sides would have to be cut for the lock to fail.

Despite the meaty girth of the shackle, the internal clearance of the lock stands at 80mm x 140mm / 3.2in x 5.5in, which means it’s comparable to a small U-lock.

Altor SAF lock on rack
The lock is almost comically oversized.

The lock is obviously a highly specialist option aimed at those who want to leave high-value bikes unattended for long periods.

The SAF Tech is undoubtedly impressive but we reckon the near-comical size of the lock alone would also make it a more effective deterrent than a typical lock. 

Where to buy Altor SAF lock

The Altor SAF lock is live now on Indiegogo and, as of writing, has had just over $1,800 pledged towards its $62,500 fixed goal. 

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If the campaign reaches this goal, locks are expected to ship in March 2020.