What Thickness Security Chain Do I Need?
The right thickness comes down to one trade-off: how much you need to carry the chain versus how much attack resistance you need. As a starting point:
- 11mm — bicycles and lighter-duty use, where weight and portability matter most
- 13mm — motorcycles or bicycles where the chain needs to travel with you
- 16mm — our usual recommendation for a motorcycle kept at home
- 19mm–22mm — maximum security for stationary installations (garages, sheds, secure parking)
At a glance
| Thickness | Best suited to | Portability |
|---|---|---|
| 11mm | Bicycles, lighter-duty security | Most portable |
| 13mm | Motorcycles/bicycles needing to travel | Portable over short distances |
| 16mm | Motorcycle or garage security at home | Usually too heavy to carry routinely |
| 19mm | High-value motorcycles, maximum stationary security | Stationary use |
| 22mm | Maximum-security stationary installations | Stationary use only |
11mm: lighter and easier to carry
Easier to handle than the larger Protector chains, but not equivalent to 13mm or 16mm in resistance. If bolt croppers are a realistic threat, move up to at least 13mm.
13mm: strong security with some portability
The practical middle ground — large enough to resist manual bolt-cropper attacks, while still manageable to carry. We recommend it for motorcycles that need to travel with the chain, or for bicycle owners who want more than a standard portable lock provides.
View the Protector 13mm Security Chain
16mm: our usual recommendation for home security
A significant step up in resistance without the extreme weight of 19mm or 22mm. Best kept at a fixed locking point rather than carried daily, and works well paired with a ground anchor. If you lock your bike in a garage or shed, the 16mm offers excellent security. However if you lock your bike outside, you might want to step up to a 19mm, depending on the threat level.
View the Protector 16mm Security Chain
19mm and 22mm: maximum stationary security
For customers who put resistance ahead of portability entirely. These chains are heavy and not a daily carry. We recommend this thickness of chain if you're securing your motorcycle for long periods of time outside.
Keep the chain off the ground
Whatever thickness you choose, a chain resting on a solid surface gives an attacker a hard surface which means they can more easily use an angle grinder or bolt croppers. A shorter, well-positioned chain will be harder to attack than a longer one left lying on the floor.
Thicker isn't automatically better
The heaviest chain only helps if it's actually used properly and consistently. A 16mm chain on a strong ground anchor, correctly positioned and locked through a solid part of the bike, will usually beat a heavier chain that's awkward to fit and gets used through a more vulnerable position, for example just through your motorcycle's front wheel.
One more check: confirm the chain's internal link clearance — not just the nominal diameter — fits your lock.
Next, read Standard chain or noose chain: which should I choose? and 13mm vs 16mm security chain.
