wookster,
The S&S couplings need strength to undo even with the necessary sizes of dedicated spanner - not something I would expect an opportunistic bike thief to carry.
If your bike is locked to a solid object with a gold rated lock through the rear triangle, lock attached to a high quality cable through your front wheel and both wheels fitted with pitlock skewers this leaves the bike reasonably secure.
A thief could still undo the S&S couplings, remove the stem and slide the forks out. This would leave the front section of frame at risk. Would a thief bother for only this bit of a bike?
Enjoy your S&S raven, secure your bike as above and let bike insurance cover any theft attempt.
