Originally Posted by
Steely Dan
not necessarily. not all bike thiefs intend to ride off on the bikes they steal. some bike thiefs in chicago work out of vans, so they would only need to cut the one u-lock attaching the frame to a secure object, throw the bike in the back of a van, and then cut the other u-lock attaching the front wheel to the frame when they get back to their lair and have all the time in the world to do so. if possible, it's best to have two separate locks securely attaching the frame of your bike to a secure object. that's still not anywhere close to foolproof (unfortunately, nothing is), but two points of connection between your frame and a secure object utilizing two different types of lock might be enough of a nuisance to make a thief pass over your bike for an easier picking.
+1 the thieves that are organized will have enough tools at their disposal. but anchoring the bike with a couple different locks to different points will definitely make them think a bit more on the effort/risk of getting caught. another thing to watch out for is that the bike is only as secure as the bike racks that you lock them to. i've seen bike racks that have had the anchor bolts removed or compromised by some thief waiting for an unwary cyclist to lock their bikes to.