The OnGuard Mastiff 8020 is a chain with an integrated lock. The product is priced at $90. The chain supplied is 3.5′ long. The links used in the chain are 10mm(0.39″) reinforced titanium links. The chain is aesthetically mated interfaced to an X2P Dual Lock Down head with a double rubber lining cover for good protection from shocks and hits. The manufacturer assigns the Mastiff 8020 a security rating of 78. This locking system comes with five laser cut keys, including one that can act as a torch with a bright beam. OnGuard offers anti-theft insurance provided the purchase is registered within 14 days.
The OnGaurd Mastiff # 8020 is very very heavy, that makes it difficult to carry around when not used to secure the bicycle. It feels a tad more difficult to use compared to the U-locks. But as the genre of chain-locks like the OnGuard Mastiff # 8020 allows for more uses e.g. securing bicycles for powersport and also normal bicycles. The chain on the Mastiff # 8020 is long enough to tie the bicycle to any pole. The built feels sturdy, as OnGuard claims to reinforce the metal used with titanium. This chain will be very difficult to break even using a bolt-cutter. So, perhaps if you have secured your bicycle to a solid structure the thief will choose another bike to steal. But whats worrying is that OnGuard the manufacturers have rate the Mastiff # 8020 at 78 out of 100. And the security rating is only Sold Secure Bronze.
One of the issues with the OnGuard Mastiff # 8020 is that the key will not insert all the way and this feels as if the tumblers are not aligned properly. Sometimes it may get little bothersome till you figure how to lock it quickly. Also, there may be issues in extreme cold when the lock may freeze and applying force may crack the lock. The OnGuard Mastiff # 8020 appears true to its name as its looks alone would deter thieves from attempting to breach this lock.
But the biggest problem with the Mastiff # 8020 is its heaviness. As its built with links 12 mm in thickness, the chain becomes very heavy (6.3 lbs or almost 3 kg). The weights can be felt even when riding the bicycle with the chain wrapped around somewhere. The OnGurad Mastiff # 8020 not only makes a good lock but also a very potent weapon in case of a street fight with the thief.
Long story short, beyond the tall claims by OnGuard, the Mastiff # 8020 is a very very heavy chain mated with a lock. The looks of the Mastiff is very assuring which is enough to discourage the thief, but that is all there is. It will be wise to research the available options in the same price range. The OnGuard Mastiff 8020 is not fit to be recommended for purchase with its current specifications and performance.