kabrus alarmed padlock, whack it on the chain.
job done.
[IMG]http://greasedlightningcycles.com/images/KABRUS%20LOCK%20AND%20BATTERIES.jpg[/IMG][/quote]
+ maybe
Kabrus D-lock ?
[url]http://www.amazon.co.uk/Kabrus-Lock-Securing-Motorcycle-Motorbike/dp/B003VV4LC8/ref=sr_1_1?ie=UTF8&qid=1309288268&sr=1-1-catcorr[/url]
17mm shackle and an alarm built in.
(apologies