Originally Posted by anonyy
I have no idea what abeater is, so anyway how should I be locking the bike?
A beater is a used bike you buy for cheap like under a $150, you take this to risky places where you normally would lock your good bike. If you take your good bike worth say $1200 (I have no idea how much your bike is worth, I'm just throwing a number out), and spend $150 in a lock and find out at some point the lock either failed or they stripped your parts off that bike then your out of a nice bike. Instead buy a beater as mentioned earlier, buy a less expensive lock of around $40 range and lock that up instead. Then if someone takes the bike your not crying.
If for some reason what I said doesn't jive with you and you still want to use your good bike, that's entirely up to you. In that case the cable lock you currently have is insufficient, but buying three locks is not necessary either. I would use the cable lock, then buy a really nice Kryptonite New York Standard that has a 16mm shackle with an 8" length. Then you simply remove the front wheel and place it along side the rear slightly forward so that you can lock both the rear wheel, the frame (the seat tube, or stays, not the seat post) and the front wheel to a solid sturdy object, if you can't get the U-bolt to fit that way then just the frame and the rear wheel to the the object. Then you take your current cable lock and run the cable through the front wheel and around the rear wheel and the frame to the same sturdy object.
There are videos that show how this is done, but be careful because some are showing the incorrect way such as this one: http://www.hulu.com/watch/95068/howdini-how-to-properly-lock-up-a-bike This guy fails to lock his rear wheel to the frame to the solid object. I do like his idea of taking the front wheel with you though, but sometimes depending on circumstances you may not be able to that. Like I said earlier ideally if you can't take the front wheel with you, then remove and attempt to lock the front to the rear and frame and object. If you can't do that do to limited reach then you will have to use the cable to lock the front to the frame to the rear wheel to the stationary object.
Some videos show a person using both a U-lock and a cable, but using the U-lock as the lock for the cable instead of having a separate lock for the cable, I don't agree with this method because once the U-lock is defeated so is the cable.
All of these videos show a person locking to a pole or such, in a bike rack though it's a bit different, you should back the bike in instead of nosing it in and lock the rear wheel to the frame to the rack, again either take the front wheel with you or bring it to the rear so you can lock both wheels, frame and rack together, or if the U-lock won't reach and you can't take the wheel use the cable to secure the front wheel to the rear wheel and frame to the rack.
I like the idea of having two different locks because the thief would then have to carry two different kind of tools to defeat the two different kind of locks, and their simply not going to that because it looks suspicious moving around in public like that! Even a person adept at picking a lock would have to spend more time picking two locks then just one. Thus with two different type of locks the thief will more then likely move to an easier target.
Using a beater bike instead means you don't need to buy another lock just use the one you have.
I hope this lengthy BS has helped.