OnGuard 8020 Mastiff
The OnGuard 8020 Mastiff offers lower security due to a thinner shackle and higher failure rates, making it an inferior choice compared to newer models.
Consolidated from 2 independent outlets
See the sources2 of 6 research runs entered this as a product to avoid rather than a pick.
This older model is frequently cited as overhyped; its shackle is thinner than newer variants and it shows higher failure rates in lab tests. Buyers are better served by the newer RockSolid 8590 or Hiplok DXF for comparable price.
Flagged 29 July 2026
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Pros & cons
- ✓ Heavy-duty chain
- ✓ Balanced weight and protection
- ✓ Suitable for e-bikes
- ✓ Best chain lock overall
- ✓ Robust steel core
- ✗ Thinner shackle
- ✗ Higher failure rates in lab tests
- ✗ Marginal security gains compared to lighter U-locks
- ✗ Higher price point than comparable options
- ✗ Heavy and bulky
The sources behind this ranking
We searched the web and YouTube for what has been published about this product, then read the articles, video transcripts and comments we found.
2 positive sources
bikefella.com Article · Dec 2025 This lock combines a titanium-reinforced chain with a double bolt locking mechanism, giving me peace of mind even when I leave my bike in busy areas. Today, I’m sharing my experience using this lock and why it’s an excellent option for anyone serious about security.Read T
Top 5 Reviews Top 5 Reviews · 2.8K subscribers · Dec 2025 This isn't some flimsy deterrent. It's a serious piece of security hardware designed to give you peace of mind in those medium to high theft risk areas. What immediately catches your eye is that integrated XTP locking head. It's not just a single point of failure. We're talking about Ong Guard's XTP dual lock down mechanism, which means it's designed for ultimate pull resistance.Watch
Frequently asked questions
It ranks #11 (D tier) on our consolidated bike locks board, drawn from 2 independent outlets.
Thinner shackle. Higher failure rates in lab tests. Marginal security gains compared to lighter U-locks. Higher price point than comparable options. Heavy and bulky.
Ranked nearby in Bike Locks
S tier #1 Litelok X1
A tier #2 OnGuard RockSolid
A tier #3 OnGuard RockSolid 8590
C tier #6 1 of 6 research runs entered this as a product to avoid rather than a pick. Hiplok DX1000
C tier #7 1 of 7 research runs entered this as a product to avoid rather than a pick. Kryptonite New York U-Lock
D tier #8 1 of 2 research runs entered this as a product to avoid rather than a pick. Litelok X3
D tier #9 1 of 2 research runs entered this as a product to avoid rather than a pick. Kryptonite New York Diamond
D tier #10 2 of 3 research runs entered this as a product to avoid rather than a pick. Seatylock Foldylock Forever
D tier #12 4 of 7 research runs entered this as a product to avoid rather than a pick. Kryptonite Evolution Mini-7
F tier #13 2 of 6 research runs entered this as a product to avoid rather than a pick.