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Seatylock Mason Review

8 min read

Seatylock Mason Review U Lock

I’ve been a big fan of most of Seatylock’s products so far and have been looking forward to testing and producing a Seatylock Mason review for a long time.

If you’re interested in this U lock and want to learn more about it, you’ve come to the right place. 

Below you’ll find the most detailed and up to date, Seatylock Mason review available anywhere.

By reading this article, you’ll learn all about the Mason’s impressive security features, how practical this high-security U lock is to use, and several tips to increase your bike security skills. 

Alternatively, if you can’t be bothered to read the whole review, I completely understand!

For those of you with tired eyes, I’ve produced two video reviews of the Seatylock Mason, grab your popcorn and enjoy the two video reviews below. I recommend the comparison. 

Now, let’s find out how the Mason U lock compares to Seatylock’s other bike locks.

Table of Contents
    Add a header to begin generating the table of contents

    Overview - Seatylock Mason Review

    Pros

    Cons

    The Seatylock Mason U lock is another fantastic product produced by Seatylock. This U lock provides an unrivalled combination of portability and security, and for a lock of its quality, it retails at a very reasonable price.

    The security features the Mason provides earned it the Sold Secure Bicycle Diamond rating, sitting it alongside some of the most secure bike locks on the market

    Thanks to several innovative features, such as the Mason’s 5mm dual thickening plates, this U lock remains compact and extremely lightweight. The Masons is actually the lightest Diamond rated bike lock avalible.

    The Seatylock Mason is an excellent choice of lock for cyclists who are constantly on the move and require a lightweight yet highly secure lock to protect their bike. 

    The only real issue I have with the Mason is that it’s not supplied with a mounting system, which you’ll need to purchase separately from Seatylock.

    Otherwise, If you’re fine without a mounting system, the Mason U lock is so lightweight that you’ll hardly notice it in your backpack.  

    If interested, you can view the most competitive price for the Mason here [Seatylock website].

    Seatylock Mason 140 Specs:
    Lock Weight: 1kg (2.2lb)
    Mount Weight: 2.9oz (81g)
    Shackle Locking Space (Width): 3.3" (8.5cm)
    Shackle Locking Space (Height): 5.8" (14.7cm)
    Shackle Material: 13.75mm Hardened Steel
    Security Ratings: Sold Secure Bicycle Diamond

    How Secure Is the Seatylock Mason?

    When purchasing a new bike lock, one of the main criteria on your checklist should always be security.

    At the end of the day, you can spend as much money as you like on a super high tech, fingerprint-reading, Bluetooth, music playing bike lock, but if it offers no resistance to theft, what good is it?

    You’ll be pleased to hear the Seatylock Mason does offer resistance to theft!

    This well-designed U lock packs in multiple security features that provide fantastic protection levels for your bike.  

    Security Features

    It’s become apparent to me that when it comes to security, the Seatylock team don’t mess around. 

    The Mason uses a double bolted locking mechanism that provides a high resistance level against twist and hydraulic attacks. Additionally, this means that the shackle would need to be cut on both sides for a thief to gain access to your bike.

    Usually, the mechanism housing of slimmer U locks like the Mason is at risk of cracking if a large amount of pressure is exerted on the shackle. Not a problem for Seatylock. 

    Seatylock Mason double bolted locking mechanism

    The engineering team behind the Mason addressed this vulnerability and installed dual thickening plates on top of the Mason. These significantly increase the security this U lock offers, whilst allowing it to remain slim and compact.

    The Mason’s 13.75mm hardened-steel shackle has a patented triangular shape, making it impressively challenging to keep in the jaws of a pair of bolt cutters, let alone cut through. 

    Additionally, compared to a circular shackle of the same width, the Mason’s triangular shackle provides 30% more resistance against twist and hydraulic attacks.

    In this video, you can watch me struggle hopelessly to make a mark on the Mason with a 36″ pair of bolt cutters. These are typically way bigger than anything a thief would carry on the street, as they’re too big to conceal.

    36 Bolt cutters vs Seatylock Mason
    Bolt cutter damage

    Whilst its 13.75mm shackle isn’t thick enough to be considered “bolt cutter proof”, you’d struggle to cut through the Mason’s shackle with even the largest 42″ bolt cutters. 

    Now, although most thieves wouldn’t have the faintest idea what a lockpick is, you’ll be pleased to hear that the Mason’s slider sidebar locking cylinder offers a good level of resistance to picking, manipulation and drilling. 

    What security ratings did all of these security features earn the Mason? Let’s find out.

    Seatylock Mason Security Ratings

    Sold Secure Awarded the Seatylock Mason the Bicycle Diamond rating, which sits the Mason alongside the most secure bike locks on the market.

    The Diamond rating is the highest in the bicycle category. Alongside this top-tier security rating, the Mason is actually the lightest Diamond rated lock on the market.

    Sold Secure Diamond

    The Sold Secure Diamond rating means the Mason is capable of defeating the most dedicated attacks, which after smashing this lock around myself, is something I’d vouch for.

    The original Seatylock Mason was awarded the Sold Secure Gold rating, which may cause some confusion.

    Seatylock Mason Gold vs Seatylock Mason Diamond
    However, after changes to the Sold Secure Bicycle category structure, the Mason now holds the highest security rating. Let’s find out how heavy the Mason actually is.

    How Practical Is the Seatylock Mason?

    Without beating around the bush, the Seatylock Mason has been one of the best U locks that I’ve used to date.

    You’ll hardly Mason’s weight in your backpack and it’s smooth to operate, but it must have a few hiccups, right?

    Weight and Size

    Seatylock Mason 140 & 180 U Lock Review

    As you can see in the image above, there are two different sizes of the Seatylock Mason, the 140 and the 180. 

    The only difference between these two models is the shackle size they offer and their subsequent weight.

    Seatylock Mason 140 Seatylock Mason 180
    Internal Shackle Dimensions: 3.3" x 5.8"
    (8.5cm x 14.7cm)
    3.3" x 7"
    (8.5cm x 17.9cm)
    Lock Weight: 2.2lb (1kg) 2.35lb (1.1kg)

    As I’ve already established, at just 2.2lb (1kg), the Mason 140 is the lightest Sold Secure Diamond lock on the market.

    It’s a highly portable bike lock designed for use on the go, which is ideal for commuters and cyclists who’re constantly on the move. 

    The Mason isn’t supplied with a mounting system as standard, which is a bit of a shame, but you won’t struggle to fit this into your backpack and I hardly noticed the extra weight.

    Seatylock Mason 140 weight
    Mason 140
    Seatylock Mason 180 Weight
    Mason 180

    That being said Seatylock produce a universal mounting bracket that I’ll cover more on below. 

    If you ride a fatbike or chunky e-bike and require more shackle space, the 180 offers plenty, but remains lightweight thanks to its triangular hardened steel shackle.

    Seatylock Mason review patented triangular shackle design

    The patented triangular shackle the Mason uses plays a key role in keeping the Mason lightweight, yet highly secure.

    Put simply, less metal is required to produce the triangular shackle than a circular shackle of the same width, dramatically reducing the overall weight of the Mason. 

    Mounting System

    As stated above, the Seatylock Mason isn’t sold with a mounting bracket, which is a bit of a pain. 

    Seatylock sell a universal mounting bracket for those that need/want one. It’s slightly more expensive than what I’d like to pay, and the mount was a bit stiff to begin with, but its use becomes more fluid over time as the plastic wears slightly.

    Seatylock’s U lock mounting bracket takes inspiration from Kryptonite’s Transit Flexframe mount, but doesn’t slide around thanks to the secure cable ties it uses. 

    Seatylock U lock mount & Kryptonite Transit Flexframe

    Whilst the cable ties the mount uses provide a secure hold, their plastic corners are sharp and have the potential to damage your bike’s paintwork. I’d recommend putting a protective layer between the mount and your bike to prevent any damage. An old piece of inner tube rubber will do the job.

    The videos at the top of the page show Seatylock’s mounting system in action for those interested.

    At the end of this Seatylock Mason review, I’ve put together a quick step by step guide on how to use the mounting system. 

    If you plan on using the Mason and don’t want to carry it in a backpack, Seatylocks mount will work well, or check out my review of the Huldit universal bike lock mount.

    Quality of Materials and Maintenance Requirements

    When used on a bike lock, plastic is a material that I’m normally critical of. It shows signs of wear much faster than metal, and can become brittle if exposed to the elements for long periods of time. 

    The inner mechanism housing of the Seatylock Mason is encapsulated in a hardened plastic shell, which I was sceptical of until I  drop tested the Mason.

    After dropping this tough U lock from shoulder height onto concrete several times, its plastic housing was showed minimal wear.

    Seatylock mason drop test
    Drop test results

    Additionally, the plastic used by the Mason is UV protected, so its polymer structures are much more resistant to degradation from harmful UV and UVC radiation than cheap and cheerful bike locks. 

    Seatylock ship the Mason pre-lubricated, and whilst I don’t think you’d have major issues if you didn’t,  I’d recommend re-lubricating the Mason every other month to keep it working smoothly.

    This short guide will teach you the essentials of bike lock maintenance, have a read.

    Locking Mechanism and Operation

    As I’ve touched on already, the Mason uses a slider sidebar locking cylinder. These are commonly used by cars and other high-value automobiles.

    Three keys are provided with the lock, which can be replaced if you lose any (at a small cost), using their custom key code.

    The Mason’s locking cylinder is smooth to use and provides good resistance to picking and manipulation. 

    Keys used to unlock the Seatylock Mason

    An automatic keyhole cover sits on top of the Seatylock Mason’s locking cylinder, preventing dirt and grime from entering the keyhole. This feature ultimately prolongs the life of the lock and reduces the amount of maintenance it demands. 

    Unlike most U locks which separate when unlocked, the Seatylock Mason’s spring-loaded locking mechanism holds the shackle in place until you’re ready to lock your bike. A feature which I appreciate.

    Seatylock Mason review - automatic keyhole cover
    You won't need to remeber to close the Mason's keyhole cover, but it is made of plastic, so shows signs of wear quite quickly.

    However, take note, when unlocking the Mason, always remove the shackle in one firm, clean motion. If removed slowly, the spring-loaded mechanism takes more effort to disengage.

    After using the lock for the first few times, you’ll see what I mean. All that’s required is a firm tug to release the shackle smoothly from the locking mechanism.

    Is the Seatylock Mason Worth Its Price?

    As we’ve established, the Mason is the lightest Sold Secure Diamond rated bike lock out there. 

    It’s not the most secure bike lock in the Diamond category, but it offers increased portability compared to its competitors whilst providing great levels of protection against a wide range of attacks. 

    After having used the Seatylock Mason for several weeks with my bike, I think it’s reasonably priced [Seatylock website] for the quality of lock your receiving, and compared to your alternative choices. 

    There are a couple of cheaper Diamond rated U locks, but these use ower quality materials and won’t last as long as the Mason. 

    For a bike lock that offers a great combination of security and portability, the Mason is very fairly priced, view the most up t date price here [Seatylock website].

    Are Seatylock a Sustainable Company?

    There’s no denying that it’s crucial for all of us to consider sustainability when purchasing a new product.

    So moving forward, I’ll be asking every brand I work with what they’re doing to reduce their environmental impact and promote sustainability. 

    I spoke with Michael Shenkerman, CEO of Seatylock, who informed me that Seatylock are currently working to reduce plastic by shipping online orders with simple cardboard packaging.

    He said that “We’re (seatylock), planning and working towards shipping all of our online orders without any plastic blister packaging”.

    This makes the recycling process easier for consumers and reducing plastic production is a step in the right direction.

    As it stands, however, Seatylock should be doing more to increase the sustainability of all of their products, not just their packaging.

    Seatylock Mason Warranty

    As standard, the Seatylock Mason comes with a three-year warranty which covers the U lock from material and workmanship defects.

    Ignore the key fob in the images shown, I’ve spoken with Michael, who confirmed the warranty had now been extended to three years.

    I have complete confidence that all of Seatylock’s products will last much longer than this, especially if you learn my key tips to bike lock maintenance. 

    Additionally, Michael told me that if customers ever have a problem with a Seatylock product, they can get in touch, and Seatylock will generally replace the product free of charge.

    What's Included In the Box?

    • Seatylock Mason
    • 3 x Slider keys
    • Key code card
    • 2 x Seatylock stickers
    Seatylock Mason 140 & 180 U Lock Review

    How to Lock Your Bike With the Seatylock Mason

    Due to its smaller shackle sizes, you’re limited to a reduced number of locking options with the Mason. 

    That being said, the Mason provides enough space to safely secure a bike to most bike racks but it won’t fit around chunkier immovable objects such as street lights and lamp posts.

    Seatylock Mason shackle size

    The best way to lock your bike with the Seatylock Mason is to thread it through your rear wheel and frame simultaneously. It’s a bit of a tight squeeze, but it slides through if you angle the Mason’s shackle slightly.

    Bear in mind that this may not work with bikes that have thicker frames or tires, such as fatbikes.

    How to lock your bike with the Seatylock Mason

    Seatylock also sell a cable extension which is sold separately but allows you to secure additional components easily. 

    I loop the cable through the front wheel of my bike when locking up, which deters most opportunist thieves. 

    Conclusion - Seatylock Mason Review

    Seatylock Mason Bike U Lock Review

    I’ve thoroughly enjoyed producing this Seatylock Mason review.

    Throughout several weeks of testing, I didn’t run into any real issues with the Mason and enjoyed the way the lock works and the features it uses to keep your bike safe. 

    I failed miserably when trying to cut the shackle, despite using a brand new pair of 36″ bolt cutters and had a similar experience when trying to pry the shackle open with a long crowbar. 

    If you haven’t already, watch my youtube comparison video to see how the Mason compares to the renowned Kryptonite Fahgettaboudit Mini

    If you’ve read the review and are thinking of purchasing this super-lightweight U lock, you can find the most recently updated price here.

    If you’ve decided the Mason isn’t suitable for you and need some lock inspiration, check out my review of the best bike locks or these 6 uncuttable bike locks.

    Thanks for reading if you’ve made it this far. As always, lock it or lose it.

    Ciao for now!

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    Hello! My name’s James, I’m an avid cyclist and the lead editor of BikeLockWiki.

    I’ve invested over four years into researching & studying bicycle security. Now I want to share the information I’ve learnt, for free, with the online cycling community.

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