Protector 19mm ultimate uncroppable hardened boron steel chain (select length below), plus the super-compact RoundLock with both RL21 and RL21A sockets (compatible with 16mm and 19mm chains, respectively). The chain is Sold Secure Motorcycle Gold (in fact, it is Sold Secure Gold in every category) and the RoundLock is Sold Secure Motorcycle Gold/Quad & ATV Gold/Bicycle Gold/Motor Scooter Gold approved. The chain is 6.3kg/metre; the RoundLock combo is another 0.8kg. The chain is supplied with usually bronze colour sleeving, and the chain itself is finished with either zinc plating or a black finish.

3 keys supplied.

Keyed-alike available at initial order only (not available retrospectively) when ordering more than one lock together, and only amongst other RL21 locks and/or DIB-Series D-Locks. These locks can't be keyed-alike with any of the Squire locks. Please note that the Keyed Alike option must be selected for *all* locks in the set that you wish to be Keyed Alike.

This package includes the standard RoundLock RL21 socket and also the RL21A socket, allowing a beautifully close fit with 16mm and 19mm chains, respectively. The RL21A socket is custom-made to suit the Protector 19mm chain. Note that some batches of 19mm chain are a little wider such that the RL21A special socket is not required: In those situations, it is better to simply use the standard (non-chamfered) socket that is supplied with the RoundLock. The recommendation, always, is to use the closest-fitting lock arrangement that is possible.

The RoundLock can also be used as a motorcycle disc lock - Check that you have a suitable opening that will take the 21mm diameter shackle in your brake disc or disc carrier. You can then use this with a chain when at home and as a disc lock when out and about. Note that disc locks do not prevent a bike from being lifted into the back of a van, which is a common technique employed by thieves.

Price and weight shown are for the package including a 2.0m long chain - Please select alternative lengths below and the price displayed will be adjusted automatically.

The Protector 19mm chain has the following link dimensions (nominal): 138 x 63-71mm outside; 100 x 25-33mm inside, throughout its length (an elongated end link is not required). It is constructed from 19mm diameter bar. The smallest rectangular hole it will fit through is about 75 x 44mm, but that would be a tight fit and a little more space will make it easier to feed through. All but the end links are surrounded with a protective fabric sleeve (again, to protect your bike/other valuables; not to protect the chain!). The sleeve is usually a bronze colour (adding about 4mm maximum to the width noted above).

Click for more technical info on the Protector range of security chains.

Click for more technical information on the RoundLock.

The following video gives an overview of the Protector 19mm chain (opens in a new window)

Noose chains are not available for the Protector 19mm because they become so unwieldy.

The next video gives a quick visual tour of the whole Protector range of chains, from the ultimate Protector Titan chains, through to the Protector 11mm (opens in a new window)

And this video shows how to fit the lock to the chain (with a non-Noose chain) (opens in a new window)

And this video explains the SFB RoundLock, showing how it can be used with our Protector 16mm and 13mm chains and, with the optional RL21A socket, with the 19mm chains (opens in a new window)