Are Master Lock U-Locks Good? An Honest Look
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Master Lock U-locks are good value for low- to moderate-risk use, like a cheap bike, a short stop or a quiet neighborhood. They’re widely available and well rated by buyers. But they aren’t built to the same level as premium locks from Kryptonite or ABUS, so they’re not the best choice for an expensive bike in a city.
We haven’t tested these locks ourselves. This assessment is based on Master Lock’s published specs, buyer ratings and how they compare with higher-security locks.
Table of Contents
What Master Lock U-Locks Do Well
- HEAVY DUTY BIKE U-LOCK: Master Lock 8320D keyed bike lock helps secure bicycles in busy urban areas; Ideal as a bicycle U-lock and anti-theft bike lock for everyday outdoor security
- HARDENED STEEL BODY: Heavy duty bike lock is built with a hardened steel body to help resist cutting, sawing and prying for dependable bicycle security
- DISC KEYED LOCKING: Disc keyed locking mechanism provides strong pick resistance, while the double locking shackle adds pry resistance for a secure hold
- PROTECTIVE VINYL COATING: Vinyl-coated U-lock helps prevent scratches on bike frames and equipment during regular outdoor use
- BIKE LOCK SET: Includes one Master Lock 8320D U-lock with key, mounting carrier bracket and two keys; Lock body is 7-1/4 in. wide with a 9 in. shackle length
Take the popular Master Lock 8320D. For about $12, it offers:
- A hardened steel body, which Master Lock says resists cutting, sawing and prying
- A disc-keyed cylinder for pick resistance
- A double-locking shackle for pry resistance
- A vinyl coating to protect your frame
- A mounting bracket and two keys
It’s 7-1/4 inches wide with a 9-inch shackle length, so it fits around most bike racks. It has a 4.5-star average from more than 5,000 ratings.
Where They Fall Short
The main gap is steel thickness and security testing. High-security U-locks like the Kryptonite New York Standard use a 16mm hardened shackle, and the most secure models go to 18mm to 26mm. Master Lock’s budget U-locks are aimed at everyday use, not big-city theft.
Before you buy any lock for high-risk use, it’s worth checking whether a model has an independent rating in the Sold Secure bicycle database.
Master Lock U-Lock Models to Consider
| Model | Price (Oct 2026) | What you get |
|---|---|---|
| 8320D | About $12 | 7-1/4 in. wide U-lock, bracket |
| 8385D | About $17 | U-lock plus 4 ft looped cable, bracket |
| 8170D | About $19 | 6-1/8 in. wide U-lock with 8 in. shackle |
| 8285EC | About $38 | Larger U-lock plus 4 ft cable |
- HEAVY DUTY BIKE U-LOCK: Master Lock 8385D bike lock with cable helps secure bicycles, e-bikes and motorcycles; Ideal as a keyed bicycle lock and anti-theft bike lock for everyday outdoor security
- U-LOCK WITH CABLE: Includes a looped end cable for flexible locking reach and a carrier bracket for convenient transport while riding or commuting
- HARDENED STEEL SECURITY: Hardened steel U-lock body and double locking shackle help resist cutting and prying for dependable bike security
- SECURE LOCKING REACH: Bike U-lock features an 8 in. shackle length, 4 in. shackle width and 0.75 in. diameter; 4 ft. looped cable adds reach for securing wheels and accessories
- BIKE LOCK SET: Includes one black U-lock bike lock, one looped end cable, carrier bracket and two keys for convenient bicycle security
The 8385D is a good pick if you want a cable for the front wheel included.
- Outdoor heavy duty bike U-lock is best used as a bicycle lock.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit.
- U-shaped steel bike lock with key; Includes carrier bracket for easy transportation
- Bike lock features a hardened steel body and double locking shackle for superior cutting and prying resistance
- Bike lock body is 6-1/8 in. (16 cm) wide, with 8 in. (20 cm) shackle length, 4 in. (10 cm) width and 1/2 in. (13 mm) diameter
- Includes one u-lock bike lock, two keys
Who Should Buy a Master Lock U-Lock?
- Good fit: Inexpensive bikes, quick stops, low-crime areas, kids’ bikes, or as a second lock.
- Not a good fit: E-bikes, expensive road bikes, or overnight parking in a city.
Better Options for High-Risk Areas
- BUILT TO LAST: The Kryptonite Evolution Mini‑7 U‑Lock is constructed with a 13mm hardened Max‑Performance steel shackle to help resist cutting and leverage attacks, while a durable vinyl‑coated protective sleeve prevents scratches to your bike’s frame and preserves its finish.
- DOUBLE-DEADBOLT DESIGN: Locks the shackle on both sides of the crossbar for enhanced resistance against twisting and pulling. Certified by Sold Secure Gold, it also includes a high‑security disc‑style cylinder to resist picking and drilling
- VERSATILE SECURITY WITH 4‑FT CABLE: Includes a 4‑ft (120 cm) double‑loop security cable ideal for securing your front wheel, helmet, or accessories. Together with the U‑lock, it is perfect for securing bicycles and e‑bikes at work, school, or around town
- COMPACT, COMMUTER-FRIENDLY SIZE: This U-lock features interior locking dimensions of 3.25” x 7” (8.3cm x 17.8cm) and a total lock weight of 3.55 lbs (1.61 kg), providing a tight fit around bike racks to deter leverage attacks. Weather-treated components help protect against rust and outdoor exposure for reliable everyday use
- EASY MOUNTING BRACKET INCLUDED: Comes with a secure FlexFrame‑U bracket that attaches directly to your bike frame for hassle‑free transport—allowing you to carry the lock easily with no backpack or lock bag required
If you need more security, the Kryptonite Evolution Mini-7 (about $105) is a big step up. For the strongest options, see our guide to heavy duty bike locks, and check how much a bike lock costs at each security level.
FAQ
Is Master Lock a good brand for bike locks?
Master Lock is a well-known lock brand, and its U-locks are well rated for the price. They’re best for low- to moderate-risk use.
Can a Master Lock U-lock be cut?
Any lock can be cut with the right tools. Thinner, cheaper U-locks take less time than thick high-security ones.
Is a Master Lock U-lock better than a cable lock?
Yes. A hardened U-lock is much harder to cut than a cable lock.
