Originally Posted by MarkS
About chain stays -- in his photo it would be easy to include the stays with his single speed bike. But with a thicker pole, and a front derailleur, it starts getting technical. I do use this approach in some situations. But I do worry about accidentally knocking the front derailleur out of alignment.
If you're routing the U-lock's shackle through the chainstays, then one leg of the shackle will be above the stays, and the other will be below them. Do it like shown in the photo below, and the leg that's above the stays should be safely away from your FD.
If a crook uses "lift and twist" on a bike with a three pound frame and a Kryptonite or OnGuard U-lock, the seat tube turns into a pretzel. I've walked past at least two "pretzeled" bikes in downtown Houston this year. A sad sight.
One more reason I would never put a u-lock near the frame of my bikes.
If you know that's their technique, then a high-end chain lock sounds like one solution. Another would be to (drum roll) lock the bike so it cannot be lift-&-twisted, with a lock at each end. But that does make it harder to find suitable stuff to lock to.
If you look at the photo above, that would be a good technique if you can find a horizontal pipe or railing, because you cannot lift the bike at all.
BTW here is a visual on what I mentioned about locking with my chain lock through my chainring, if anyone had trouble visualizing it. The weak point on this setup is that the padlock's keyway would be a cinch to drill out using any old rechargeable drill.
