Onguard mastiff bike lock review

Why I use the OnGuard Mastiff Chain Lock

Travis GneitingBikes, Reviews

OnGuard Chain Lock Review

Why the OnGuard 8019 LP Mastiff chain lock is the lock I choose to secure my bike.

OnGuard Mastiff Lock

I have used many on guard chains and kryptonite chain locks over the last decade. While the on guard 8019 LP is a smaller diameter chain it has more convenience yet protects just as well as other chains I’ve used in the past. The single best feature of the chain is the circle link that ultimately lengthens the chain to twice its length. This is extremely convenient when locking my bike up in my truck bed. It’s easy to wrap the chain through the bike frame and use the u-lock to secure it to my truck bed D-Link.

My favorite setup is pairing the lock with an OnGuard 8043 cable that I can run through my tires. I feel like this is the ultimate in convenience and weight benefit for the protection and security of locked up mountain bikes and road bikes. There are bigger and stronger locks available but nothing over the last 10 years has been more convenient yet provided me peace of mind that my bike would be safe when running into a store or camping overnight.

No bike lock is 100% foolproof, there are ways to pick locks or cut through them with bolt cutters and angle grinders. There are tricks that thieves use to freeze locks or use car jacks to break them open. My advice is to always keep your bike in view when you can and to never rely on your lock as 100% foolproof. A lock should be used as a deterrent or to slow down a bike thief. The longer and harder you make it to steal your bike the less appealing it is to the thief. A more expensive bike like an e-bike or high-end mountain bike or road bike May incentivizes a bike thief to spend more time or effort to steal. Finding a bike lock that makes it the most inconvenient and difficult to steal is your best option for protecting your bikes.

That being said I find myself wanting to protect my bikes both in my home, in my garage, on my bike rack, in the bed of my truck, or when I am running in to grab a bite to eat or pick up something during the camping trip. The on guard 8019 LP is an intimidating looking chain that should be the first deterrent to a bike thief. There there are beefier chains like the beast 8016 that have a thicker link that would be harder to cut through but the chain length and weight make it difficult to weave through multiple bikes or attach to bike racks or lock up in truck beds. These bigger locks also have a massive 14 mm link and a short shackle you lock when positioned correctly makes it extremely difficult for a thief to cut or pick the lock. The u-lock on these bigger locks measures 55 mm and offers just enough space to run through two links of a larger chain.

Some of the features on the on guard locks that make them stand out above others are the dust cover around the chain that protects it when sliding through bikes frames the automatic dust cover in the key cylinder and a protective coating on the crossbar and shackle. On guard also offers five keys one that includes a light for the locks with the option of purchasing replacement keys if you have recorded the code on the keys when you first purchase the lock. The lock also comes with a $1001 powersports anti-theft protection offer as well as a $3,001 offer. It’s worth noting that this requires registration and additional cost for the protection and is not available in the state of New York.


OnGuard locks are not cheap but when you are spending thousands of dollars on bikes they are a worthwhile investment. I also find myself using them to lock up skis and snowboards in the bed of my truck motorcycles even lawnmowers that have all been stolen out of the back of trucks. The OnGuard locks I use have been through winters snow storms rain storms and freezing conditions and still continue to perform as intended. I also think it’s important to consider the lock that meets your needs. On guards has locks that start at under $30, if you were trying to protect a bike that was worth a couple of hundred dollars this might be a sufficient deterrent to a bike thief. It’s also worth looking at the different sizes and shapes of locks from u-locks cable locks and chain locks. If you are going to try to lock your frame and rear tire with one lock a larger u-lock would be a good option. If you also want to lock the front wheel you could add a cable lock to that setup. You can spend upwards of $200 on locks to protect your investments. It’s hard to say whether a $100 lock or a $200 lock will protect your bike any differently, a motivated thief is going to look for opportunities everywhere. A thief armed with an angle grinder against a $200 lock may only take him 30 seconds longer to cut through than a $100 lock and maybe well worth the risk involved. My advice is to take into account the value of your bike or assets and select a lock that is convenient yet provides the most protection. For me, that’s been the on guard 8019 LP Mastiff chain lock, but it might be something different for you. Consider your budget how you will be traveling with the lock and the convenience when purchasing your next lock for your bike. And remember no lock is foolproof keep an eye on your bike whenever you can even when it’s locked up.

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