The Mastiff chain lock is a 110cm chain of 10mm hardened links connected to an integral lock that uses a similar barrel to Onguard's other offerings. The chain is covered with a woven nylon sleeve and it's long enough to chain up to four bikes together if you're creative, which is a definite benefit over a U lock for garage use. There's no mount, of course, so it's only one to consider around town if you regularly cycle with a bag. or you can wear it holster style if you're a hipster.
We went after the Mastiff with our standard thieves' armoury – 30" bolt croppers, persuader, hacksaw, cold chisel and hammer – and the chain survived the allotted five minutes with fairly minimal damage. The chain links were much too hard for the hacksaw and no amount of twisting would pop the lock. We did get a bit of joy with the bolt croppers, but it would have taken a long time to snip the chain, especially since you'd have to do both sides of a link. The dust cover on the barrel got snapped off, but the lock was still fully functional despite the abuse.
Overall the performance was very good, and if you're looking to lock a bunch of bikes together in the shed then there's a 160cm version too
road.cc test report
Make and model: OnGuard Mastiff chain
Size tested: n/a
Did you enjoy using the product? Yes
Would you consider buying the product? Yes, for static applications
Would you recommend the product to a friend? Yes, for the shed or garage
About the tester
Age: 36 Height: 190cm Weight: 98kg
I usually ride: Schwinn Moab, urbanised with 700cs My best bike is: Trek 1.5 with upgrades
I've been riding for: 10-20 years I ride: Every day I would class myself as: Experienced
I regularly do the following types of riding: time trialling, commuting, sportives, general fitness riding, fixed/singlespeed, mtb, Mountain Bike Bog Snorkelling, track
Dave is a founding father of road.cc and responsible for kicking the server when it breaks. In a previous life he was a graphic designer but he's also a three-time Mountain Bike Bog Snorkelling world champion, and remains unbeaten through the bog. Dave rides all sorts of bikes but tends to prefer metal ones. He's getting old is why.