They can be heavier and more expensive than regular bikes, but many of the same rules apply.
We have quoted the 50 pound rule about bikes before:
All bicycles weigh 50 pounds. A 30-pound bicycle needs a 20-pound lock. A 40-pound bicycle needs a 10-pound lock. A 50-pound bicycle doesn't need a lock at all.
After spending some time riding some very expensive electric bikes in Minneapolis, I realized that the rule no longer applies; e-bikes are heavier than regular bikes, and they can be very expensive. So when I was at the Frostbike show as a guest of Surly Bikes, I had a long chat with the Abus representative about what the best locks for bikes are. Alas, I left my bag with my camera in the taxi on the way home, so I have no photos from that part of my visit.
We have covered bike locks on TreeHugger and MNN before, and much of the earlier advice still stands:
1. U-locks, or D-locks, are still considered the most secure.
But you have to do it right: Get as small a U-Lock as you can get way with; the smaller the space, the less chance of getting crowbars or hydraulic jacks into position. And get a good one, where both sides of it are locked in place; that way, the thief has to make two cuts. Some people use the "Sheldon Technique" where the rear tire is locked to the fixed object; evidently tires and wheels are really hard to cut through.
People tend to buy the big clunky U-locks because they don't know how to use them properly. A U-lock should go around the rear rim and tire, somewhere inside the rear triangle of the frame. There is no need to loop it around the seat tube as well, because the wheel cannot be pulled through the rear triangle.
2. Chains are the most resistant to angle grinders.
These battery powered grinders will eventually go through every kind of lock, but it is really hard to hold a chain and grind at the same time. Chains also require two cuts.
3. Folding locks are convenient, but not as secure.
These new locks are made of plate steel and fold up into a little carrier, much easier than dealing with U-locks and much lighter than chains. But they only need one cut, and some say that pins can be drilled through.
4. Don't even bother with cable locks.
I use a cable lock to secure my tires and just slow the thief down a bit, but as Yvonne Bambrick writes in the Urban Cycling Guide, the cheap thin versions are "like locking your house with a screen door."
5. Use multiple locks.
Our Abus representative, who has some of the best locks in the world at his disposal, lives in Chicago, where there is a lot of bike theft. He adds a lock for every hour he is leaving his bike alone; "if I go to a three hour movie, I put three locks on the bike." In Toronto, where I teach at Ryerson University School of Interior Design, I have been using two locks – a little Abus Granit U-lock and a thin cable. I think it is time to upgrade the cable to a chain or a folder.
Some other tips:
Lock to something solid and legal.
This friendly and welcoming sign in Fort Lauderdale sent me somewhere else for dinner. But when these companies come with their trucks and big grinders, they get your bike in seconds. And don't lock to trees; it is bad for the tree and it might well get chopped down just for the bike.
Lock it in a public place
This doesn't always help; I saw a bike thief at work at a busy intersection in Toronto, he was twice my size, and I wasn't going to confront him. Casey Neistat made this hilarious but maddening video where he uses everything from bolt cutters to angle grinders to steal (his own) bikes, even in front of a police station!
Document your bike and register it.
The police don't do much if your bike gets stolen, but who knows, you might get lucky if they have all the information and catch a bike thief. I suspect also that, as more baby boomers ride more expensive e-bikes, that the police won't be able to just blow them away.
Demand proper, safe and secure bike storage at your office and in your community.
This is perhaps the most important thing. More and more zoning bylaws are writing bike parking in, the way they do car parking; LEED and other certifications encourage bike storage and changing facilities. These should be in every building.
There should be decent bike parking on the street too; I have been in Toronto's entertainment district where they tell us not to lock our bikes to the trees, but can you find an open ring anywhere? No, because there is simply not enough bike parking to meet demand. Nobody wants to lock their bike to a tree but you have to provide some options.
The proliferation of expensive and heavy e-bikes is going to change the discussion of bikes in cities, and probably change the way we think about locking them. More bikes will have alarms and GPS tracking and high-tech solutions, but the basic rules will still apply: Buy the best lock you can afford, and then buy another one.
Other resources: There is a lot to learn from The Best Bike Lock.