Under Construction

Tools of the trade:

                       Angle Grinder      Hydraulic Bottle Jack Frozen lock smashed
Medium size bolt cutters (shown) can cut up to 12 mm.
Large (36 and 42") bolt cutters can cut 13-15 mm.
Cordless angle grinders are now the tool of choice for professional bike thieves.
They're smaller than bolt cutters and will cut thru most anything.
A bottle jack can be used to force a U-lock open.
When cooled to -13°F with canned air spray like dust-off (actually the compressed chemical difluoroethane [152a], which replaced freon), even very tough locks become brittle enough to smash open with a hammer.

Risk Factors:

 - Expensive bike
 - In a big city or college campus
 - Leave it unattended for more than 1 hour
 - Combination locks are easier to pick
You-tube videos of thefts:
SF Police stake out| ABC news |
Locks listed in order of safety.
Type Price. Diam.1 Length2 Weight3 Pros/Cons
U or D lock $35-$100 13 mm

16-18 mm

4 x 9"

4 x 6"

2.8 - 3.2 lbs

4.5 lbs

Most come with a bracket to mount on the frame of your bike.
Kryptonite New York Standard Heavy Duty Bicycle U Lock Bike Lock $85 ( 16 mm, 4x8", 4.5 lbs)
Chain Lock $15-120 9-12 mm 21"-30" 3.9 - 7 lbs Can wrap around seat post
At 12 mm only the shortest chain lock is portable.
Kryptonite New York Fahgettaboudit 1415 Chain $130 (14 mm, 5', 15 lbs)
Folding lock $20-150 5 mm 33" 2.2 - 3.5 lbs Most compact.
About the same internal space as a U-lock but flexible.
Cable lock $6-20 ¼", ⅜" (9.5 mm)
and ½" (12.7 mm) 1
Std 4- 8'


0.7-2.2 lbs Can wrap around seat post.
Where I used to live in the suburbs, there are no bike racks, so I had to wrap it around a tree at the grocery store. It required 6½' to go around a 1 1/2' diameter tree.
20 mm Kryptonite HardWire $46 (2 3/4' 3 lbs)
1. Diameter of part that must be cut.
Cable locks are braided steel wire and the vinyl coating is included in the dimensions so the total amount of steel is less than the same size U lock.
With many U-locks you only have to cut 1 side and you can lever it open. But the the Kryptonite New York lock has a "dual bolt" design that forces a crook to cut both arms of the shackle.

2. Length - Typical lengths - Cable and Chain locks must be twice as long to wrap around their anchor.

3. Weight - Anything over 4.5 lbs is difficult to cary around.

U-lock vs Chain lock: Which is best? | The Best Bike Lock says,
If youÕre looking for a portable lock to secure your bike in the street every day, then youÕre probably best off with a U-lock. Whereas if youÕre only looking for a lock to protect your bike at home or at work, then the best choice is a thick, high quality chain lock.

At 5 Things Bike Lock Companies DonÕt Want You to Know Daniel Idzkowski recommends SkunkLock which releases noxious chemicals when thieves try to cut through your lock.

How to Lock:
Lock should go around the back tire and thru the triangle part of the frame.
Fill up the spare room inside the U so a thief can't get a bottle jack in to break the lock.

Don't allow the lock to touch the ground where the thief can smash it with a hammer.

One blog post said "A person intent on stealing bikes can beat any lock in a short amount of time--no matter how much you paid for it. Make sure your bike looks like its worth less than it is, and alway park it next to a bike that's worth more and has an easier lock to pick."

The Best Bike Locks For Keeping Your Wheels Safe | Popular Mechanics Best Bike Locks for 2018 - Reviews of Bike Locks
The Best Bike Lock: Reviews | Wirecutter
The 6 Best Bike Locks in 2018 | The Best Bike Lock
The best lock to protect your bike. | Slate
How to Choose Bike Locks | Eastern Mountain Sports
The Proper Way to Lock Your Bicycle | LifeHacker
How to lock your bike (properly!) | The Best Bike Lock
5 Things Bike Lock Companies DonÕt Want You to Know | D Idzkowski

last updated 19 Oct 2018