abdon 

This is a general biking question but considering that all my bikes are vintage, and I'm sure some folks here lock their bikes, it should apply here.

How strong are they against bolt cutters and the like, provided that you lock them high so the cutters can't be leveraged against the ground? I imagine better than cable locks, worse than U locks? Is there a lot of performance difference between the top of the line and mid tier ones?

brewerkz 

Park you bike near a more expensive bike with a cheaper lock.......otherwise all locks are easily defeated, keep your valuable bike with you.

merziac

Never as a primary if you will be out of sight, they are fairly easily cracked open without bolt cutters.

Maybe as an addition to a serious U-Lock, I use 2 U-Locks and a cable for the Brooks when I need to lockup and usually ride a lesser bike for those rides.

Yes the U-Locks are heavy, I carry them in a backpack so they are more manageable.

merziac

Not so true anymore, the new Hiplock D1000 is almost angle grinder proof, heavy as a brick and a bit short so....

Krypton NY are pretty good too, but.....

ABUS Granite X too, also very heavy.

I use 2 of the above and a cable for the Brooks for shortish lockups, Dr. appt. and the like, etc.

abdon 

Where I am I don't think there is a whole lot of professional bike thieving but there is a f* ton of petty thieving. Early this year I was helping a lady find a replacement seatpost/saddle because somebody lifted hers from her crummy college mule of a bike. Not hating on the bike, but it was the short of bike you ride and think nobody would steal. Well she locked it and somebody took the plastic saddle. :/

But that's Anchorage for you. Most of my haunts are away from the city. I'm replacing my quick release skewers and seatpost bolts with anti theft ones and don't plan on the bikes being unattended for long. I'm hoping to find a locking gizmo that is relatively light and relatively bolt cutters proof.

P!N20

Nay

wschruba

2 quick defeats, one of which is common to any keyed lock:

1) drill the lock (seriously, 10 minutes, tops. 5, tops, if you have appropriate tooling for it). Through the core, snap, turn, lock is off.

2) the bar pivots are the weak point, and if they can be leveraged against each other (like with a crowbar), you can pop a plate off.

I suggest you visit a few shops in your area (especially if it's a city), and ask what they recommend. The all-sufficient 1/4" cable that works for the cafe stop where I am, wouldn't work for locking it at the train station.

Steel1

Don’t ride and lock up something if you will be really disappointed if it gets stolen or vandalized.
Just get a good beater bike for which you won’t be crushed if it disappears.
I have a very nice commuter/urban/bar hopper with only about $250 investment total. I lock it with an ancient U bolt plus cable for the front wheel. The U bolt is very patina’d and probably vulnerable to Bic pen attack. It doesn’t draw so much attention and flies below the radar.

RiddleOfSteel

I have the beefiest folding Abus lock. It's 3.5 lbs and sucks to carry around, but it's better than walking home (to me). When I bought it, it had the highest anti-theft rating and I watched a guy with 3 foot (or longer) handle bolt cutters at the pivots and it didn't work. Normally I ride from what I call "protected Point A" to "protected Point B" so a bike lock is not needed. For the few times I can't do that, then yeah, I strap the lock to the bike and deal with the considerable increase in ballast.

abdon 

I would be equally disappointed and crushed if any of my bikes gets vandalized or stolen, whether it is a $500 vintage or a can't-even-give-away beater. The monetary loss may be greater but the pisstoffery would be the same. Rebuilding Suntour wheelsets takes the exact same amount of effort than rebuilding campy wheels.