Seatylock

Seatylock Mason 180

Name: Seatylock Mason 180
Brand: Seatylock

The lightest Sold Secure Diamond-rated lock on the market uses a triangular shackle profile that cuts weight, not resistance. An automatic keyway shutter and 3-year warranty support daily carry over brute mass.

$80 typical

Check availability

EDITION 01RESEARCHED 2026-08-042 SOURCESREFRESH DUE 2027-01

SUBSTANCE SCORES

substance7.9/ 10

design8.0/ 10

value7.3/ 10

WHY THE PRICE IS JUSTIFIED

The value is engineering-led rather than prestige-led: the triangular hardened-steel shackle saves weight, while double deadbolts and an automatic shutter deliver Diamond certification. It remains conventional steel, so do not mistake that certification for grinder immunity.

MATERIALS

ShackleHardened alloy steel, triangular profile

Uses less metal than a round profile while maintaining a stiff, cutter-resistant shape.

Locking systemHardened double deadbolt

Improves resistance to twisting and single-sided prying.

Keyway protectionAutomatic weather cover

Reduces dirt and water entry, a common long-term failure point.

CRITERIA

8/10

Attack Resistance

Sold Secure Diamond conventional-lock certification and 13.7 mm triangular hardened shackle.

9/10

Locking Architecture

Double deadbolts plus a triangular profile designed for strength/weight.

8/10

Real-World Reliability

Automatic keyway shutter protects against grit and moisture.

7/10

Fit And Versatility

Compact 180 format is less flexible than long U-locks.

9/10

Carryability

Independent review calls it the lightest Sold Secure Diamond bike lock.

9/10

Operational Value

Useful weather protection and engineered geometry around $80.

IDEAL FOR

·Riders who carry a lock every day
·Moderate-risk urban parking
·Bikes with tight frame-mount space

NOT FOR

·Grinder-heavy theft areas
·Very thick rack hoops or cargo-bike tubes

DESIGN & ERGONOMICS

One of the most thoughtfully shaped conventional U-locks: quiet spring-loaded handling, a clean triangular silhouette and low mass. Its compactness is security-positive but does demand checking your usual rack and rear triangle first.

LONGEVITY

Three-year warranty. The shutter and hardened construction should help in wet commuting; maintain the cylinder and confirm a bracket solution, since it is sold separately.