I have the cheapest of cable locks. It's a $7 Wally World cable lock. Definitely theft deterrent not theft proof. Its very clumsy to use and the combination lock is quite fiddly. I thought I'd ask Santa for something better. I'd like something compact and was thinking of one of the folding locks I see. Are there any that can be clamped to the frame without messing up the fold?

What do you use?

These folding locks like the Abus Bordo can be broken very easily, they are useless.

Locks such as Abus Bordo can be defeated. IMO they are a step up from cable. I use a security chain and lock. I like it best because it gives me more options on what I can lock to. I think it also is less likely to be defeated by most thieves using either a large bolt cutter or portable grinder with a steel diamond bonded grinder. Yes it is vulnerable to the latter but harder to on a chain than U-lock. This is due to that the chain flexes. On bench or with some support the U--lock would be better. Myself, I have used a corded angle grinder with a composite blade to cut this chain but the only way I could do it is to clamp the chain down to a work surface, otherwise the wheel can jam and explode into pieces. The chain and lock weigh 3 pounds so likely less than a good U-lock. There may be better options

Many Brompton resellers propose the Bordo to their customers because it can easily be transported on the Brompton.

There are plenty of reports of stolen Brompton "protected" by a Bordo!

I agree with you that cutting a chin with a portable grinder is more difficult than cutting a U-lock but a strong chain (it must be thick enough, otherwise it can be cut by a bold cutter) is heavy and difficult to carry on a bike while its easy to carry a U-lock with a dedicated mounting system.

There are now portable grinder resistant U locks like the Hiplok D1000 and Litelok X3.

I guess it also depends on how it will be used. Mine would be used to lock up at the library and gym and farmers market. These tend to be pretty high theft areas. But I'd be there during the day and for an hour at a time max. There's a great YouTube video where a guy tests a half dozen or so locks from Amazon. His tools he uses to "steal" the bike range from "hard yank" to Cutting wheel. Not surprisingly, my lock was broken with a hard yank. Since I'm not leaving it overnight I'm not terribly worried about our local bike thieves whipping out a diamond cutting wheel. I know who steels the bikes and if they had a nice power tool like a Sawzal, they wpuld just trade it for meth rather than use it to steel a folding bike.

All locks are vulnerable. I use a folding lock. I'm not in a high crime area. If I feel like I need more security, I make my bike slower to steal and less desirable by folding it, based on the assumption that a thief will always choose the easier and faster mark

I use an abus chain with kryptonite nyc mini u lock in moderate crime areas. Although it’s probably overkill considering my lock is worth more than my folding bike.

I use a Bordo 6100 on my titanium bike. It is not my most expensive bike, but it looks like my most expensive bike. Not as good as a U lock, but I did not want a U lock due to the large shape of it. I think it is similar to a U lock for unfolded size and ability to lock a bike to a sign post or bike rack. But for high theft areas I instead ride my errand bike, a 30 year old bike I bought at a garage sale for $5, although that bike needed $50 in parts to make it ridable a decade ago.

The Bordo bracket is strapped to a tube on the bike. I had a slight rattle that bothered me, also using a velcro strap around the lock and tube cures that. I got the longer length of lock. This lock and bracket is quite convenient to use. I want a combination lock so I do not worry about forgetting or losing a key. The Bordo hangs below my top tube in the photo.



On a bike tour, I often bring a second lock. A short heavy cable, note the padlock is one of those weird ones that I think theoretically are hard to use a bolt cutter, below. Of the three options I am showing here, this is the least convenient. I bought the combination padlock separate from the cable. I think this cable is only 3 feet. But using both that cable lock and the Bordo makes me pretty confident that my bike is reasonably safe.



But if I am only going to be in a convenience store for 5 minutes or if I was sitting in a restaurant where I can see my bike out the window, I want the ultimate in convenience, then I use a skier type lock that is no more than an inconvenience for an opportunist type of thief, as below. Even a small cable cutter could cut that. But I am hoping nobody has a cable cutter in their pocket when I lock up the bike with that lock. I would never use this in high theft areas.

I use a medium-weight lock like this on my 20-inch folder:

Even though my 20" folder doesn't have quick-release wheels, I try to run the cable though the wheels. I will also lower the seat and run it through the seat frame.

My 16" folder has a medium to light cable and I fold it up. But now that I have invested so much time in upgrading the 16" bike, I may get a heavier lock. Although I suppose if I know before hand I was going to need to lock it up I would take one of the heavier locks and chains from tone of the other bikes.

This shameful image was actually on Abus' website:



That expensive folder could be stolen with a hex key. Try this instead:




It's not just your primary lock (try a Litelok X3 or, where legal, a Skunklock V2). Secure the peripheral componentry with theft resistant fasteners. Lotsa companies offer such devices, like:

https://www.bicyclebolts.com/

https://designbydelta.com/products/h...curity-skewers

https://hexlox.com/

https://www.pinheadbikelocks.com/

https://www.pitlock.de/en/

Here's an expensive but SOLID suggestion... Kryptonite New York Fahgettaboudit Chain 1415 & New York Disc Lock

I use a Kryptonite chain/lock combo, but not something as good as this.

But 10.8 pounds?

Yeah... It's a BEAST!!! They have other, lighter weight models available. Kryptonite makes some of the best bike chains/locks on the market. They even insure the bike against theft.

That’s what I use when commuting and have to lock up where I can’t see for 20-30 minutes. Heavy as hell but toss it in a pannier and I don’t notice it.

I live in a very high bike theft area but I have not lost a single bike using this U-Lock. Nothing special, but it gets the job done. I have three of them because I am frequently switching bikes. All the keys are duplicated on my wife's key ring. For the folder I just lock it around the frame. Sometimes I get cute and lock across the seatstays, but around the main beam is just fine.