Victory Vision Tour
Why It Won't Be Stolen: You guessed it, this thing is enormous. 869 lbs (dry) and 103.5 inches long. Good luck pushing this beast down the street, much less loading into another vehicle. To top it off, Victory has sold fewer bikes in its entire lifetime than Harley sells in one financial quarter, so there's just not going to be huge demand for one of those Buck Rogers headlights.
Honda Rebel 250
Why It Won't Be Stolen: See? It's not just heavy bikes that are theft proof. Honda's ubiquitous learner bike has been around largely unaltered since 1985 and, well, just doesn't meet the desirability standard necessary to make stealing one a compelling thing to do. There's so many of them out there, for such low prices, that you could likely buy an entire bike on Craigslist for less than the minimum payoff thieves require to justify the effort.
Harley-Davidson Tri-Glide Ultra Classic
Why It Won't Be Stolen: Harleys do get stolen, but who'd steal a 1,157 lbs trike? I mean, what would you do with it after? Fence to to a drug dealer?
Any Electric Motorcycle
Why It Won't Be Stolen: Thieves who do not read RideApart have no idea what any of these things are. Also most of the ones on the road have exceptionally poor component quality. Think mountain bike, not motorcycle. We suppose some broke engineering students could find a use for the batteries and motors, but anyone else is just going to walk on by.
Suzuki Burgman 650
Why It Won't Be Stolen: Another huge, heavy bike (613 lbs). Add goofy scooter looks and non-motorcycle components into the mix and there's just no burning desire to use one to attack Range Rover drivers nor any demand for stolen parts.