I constructed a simple but effective alarm-system from a (extremely loud) siren, a
12 volt relays and the mercury-switch from a central-heating system. The moment
the bike is 'straightened up' (taken from the side-stand) all hell brakes loose. It has two
downsides: First of all it does not 'reset' after it is triggered. It will
continue to 'howl' until the battery is empty. Secondly (and more
important) I discovered that hotel-clerks and security-guards are curious people
and would like to know how it feels to sit on a bike like Pam. As a result the
entire hotel wakes up and I have to get out of bed to 'reset' the alarm.
Naturally everybody swears it just started by itself.