Weird key. At first I thought the padlock was an Abus because of the yellow color, but the manuacturer is mentioned nowhere throughout the auction and there is no branding on the lock. And the keys look like some kind double wafer key with warding.
Aside from that, a chain can always be cut if there is a set of bolt cutters available. On a motorbike I would probably go for an brake disc lock. There are some manufacturers making them, Abus is one. they employ disc locks and the lock itself is much smaller and more convenient to handle than a chain like this. It consists of the lock and a bolt you put through the disc, allowing almot no room for cutters or angle grinders to work in.
http://www.abus.de/de/main.asp?ScreenLa ... 318216565m
They are certainly way more expensive than this lock-chain combo, and the mere fact that it goes for 12GBP makes me certain that the chain is some low-quality product easily cut or torn apart..
Due to financial limitations the light at the end of tunnel has been turned off until further notice.
