Originally Posted by
Usjes
The bike was so expensive because I chose the lightest components so I don't want to negate all this by then saddling myself with an unbreakable lock which weighs half as much as the bike itself.
No such thing as an unbreakable lock, unfortunately. Even the toughest U-lock will fail under an angle grinder, and the thickest cables and chains can be severed by bolt cutters if the cutters are long enough.
Still, no one ever regrets having too much lock, just too little. I like being better locked up than the bikes around me, with the thought that thieves will pass up my bike for an easier target. No matter how much lock you carry, don't leave a nice bike in a high theft area and expect it to be there when you get back. If you must leave a bike in these areas, ride your beater.
It's said that all secure bikes weigh 50 lbs; 20 lb bikes require 30 lbs of lock, 40 lb bikes require 10 lbs of lock, and 50 lb bikes require no lock at all.