Well, my fork has a rack bolted to it and my cable lock that locks my front wheel to the frame (and sometimes a stationary object) goes through the rack while the rear wheel/frame are u-locked. Sure, it's sensitive to cable cutters (or someone with allen wrenches to take the rack off), but it's better than most of the bikes I see locked places with a single lock.
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Bikes: 1996 Eddy Merckx Titanium EX, 1989/90 Colnago Super(issimo?) Piu(?), 1990 Concorde Aquila(hit by car while riding), others in build queue "when I get the time"