I recently lost the keys to my lock and had to borrow a bolt cutter to free my bike. It was a bit of an eye opener to realise a) just how easy it was for the bolt cutters to cut through my D Lock (<10 seconds), and b) that nobody on a busy town shopping street batted an eyelid at me doing so.

When choosing a new lock, what should I look for in terms of build material or design that would make it harder to cut through (using relatively small/discrete bolt cutters)?

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    Can you define what you mean by best? Best as in the most secure regardless of cost or something that has the best of everything, small, lightweight and good value for money?
    – Ambo100
    Commented Jul 3, 2011 at 11:09
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    I wasn't aware that Best made bike locks (though I guess the 11B782 would come close). Commented Oct 25, 2012 at 15:52

9 Answers 9


Get the kryptonite fahgettaboutit - as small as possible. Kryptonite 997986 18mm New York Fahgettaboudit U-Lock,Black Mini

Best lock out there. Because the shackle is 18mm thick, I don't think you could cut it with bolt cutters, so you would need a hydraulic jack -- but the opening is too small for a jack to get through -- that's the main reason to go for a smaller lock, so there is no room for the jack; or, a disc grinder to get thru it.

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    Nice suggestion, and based on the amazon reviews, it seems to be very good. However, the lock is small, which is great for security reasons, but would then need to be paired with a chain/cable in order to tie it down to some solid object. Do you have a good suggestion for that?
    – Nik Reiman
    Commented Aug 26, 2010 at 11:40
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    You can always use a D-Lock to hold both ends of a chain. But better to have a cable with it's own built in lock.
    – Ian
    Commented Aug 26, 2010 at 12:46
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    @Nik Actually, it's just long enough if you use it correctly. Place the lock your rear tire/rim, there should be enough distance to now place it around a bike rack, or any reasonable sized post. There is no need to loop it around any part of the frame because the wheel cannot be pulled through the rear triangle. Presto! your bike is locked securely, and the lock is small enough that they cannot open it with a hydraulic jack like they can larger locks. Cheers, Mike Commented Aug 26, 2010 at 16:46
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    I use this lock and it is very small. To avoid carrying a cable for my wheels, I use Pitlocks (pitlock.com) on my wheels, seatpost, and even to secure the cap on my threadless stem. It's nice to be able to grab the frame at any convenient point and not worry about taking the wheels off or trying to fit them in. Commented Aug 27, 2010 at 22:15
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    And to expand on what nick said, yes, the frame could be stolen if thief was willing to destroy the rear wheel. No ones going to do that though, they'll just walk along to another bike that isn't as well locked up and steal that one instead. Commented Apr 26, 2011 at 23:29

I like the Axa Defender that is fixed to the fame of the bike and then locks the wheel; it also has a cable that you can use to lock the bike to the bike stand. It’s great for a lock on a “everyday” bike, as you can’t forget to take it with you.

Image of bike lock alt text

As they are not common in the UK, most people don’t know how to defeat them.

As always best to combine with a second lock of a different design.

  • Yes - These are also very common in Amsterdam & Copenhagen.
    – Kevin
    Commented Aug 26, 2010 at 13:05
  • @Kevin, I don't know if they are a good option in Amsterdam & Copenhagen as too many people may know how to defeat them.
    – Ian
    Commented Aug 26, 2010 at 18:07
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    Security through obscurity is not a good method. If the lock is easily defeated with a little knowledge, then it doesn't strike me as a good lock Commented Nov 25, 2010 at 9:55
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    @Neil, All locks can be defeated with the right tools, as the AKA defender is not common in the UK it is unlickly many people will have the tools on them, or know how to use them. I don't think it is easily defeated even by someone that how how.
    – Ian
    Commented Nov 26, 2010 at 12:39
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    I don't think that was the upshot of that comment. More like, to outrun a bear you don't need to be faster than the bear, you just need to be faster than the other people running from the same bear.
    – beth
    Commented Jun 16, 2014 at 16:40

I second the advice suggesting a small U-lock. Also, see Sheldon Brown's advice for locking strategy, which has done me well so far.


Take a look here for a nice bike lock guide, and make sure you browse the comments, there are some good info there as well.

Also, there is this little trick my friend does... he has a good U-Lock but, he also uses a cheap chain lock. His reasoning is that the thief usually carries one specialized tool and would probably skip his bike, because it would require fiddling with two completely different set of tools. :)


I use a Kryptonite Evolution Mini:


It fits in a back pocket, is compact enough that it's hard for thieves to get a tool inside of it to pry it apart, and lets you lock your bike to parking meters since it is too small to fit over the top.

This lock is too small to secure anything besides the frame, so I also use locking wheel skewers and carry the key everywhere I go. This is a great combination of equipment; it only takes me ten seconds to lock up my bike.

  • I use this same lock. You can lock around the rear wheel (around tire and rim) inside of the rear triangle (between the seat stays and chain stay) in order to secure the rear wheel and frame. I use a basic cable to secure the front wheel, but am considering switching to locking skewers for the front.
    – freiheit
    Commented Sep 18, 2010 at 5:33

If you bike in a big city with plenty of street signs and bike bars to lock up to, the TiGr lock is the strongest and lightest lock you can find.

Titanium bar bike lock

It is basically a titanium bar bent in a U shape (and covered in clear plastic so it doesn't scratch your bike). The thin version weighs 11.3 ounces! You carry it on your top tube with a couple of velcros straps. It locks both front and back wheels plus your frame to any stop sign or bike parking fixture.

I got mine during their KickStarter project a year ago.


  1. Extremely light weight (11.3 ounces)
  2. Doesn't rattle on the bike.
  3. Can not be cut with bolt cutters
  4. Takes much longer to grind through than a Kryptonite lock


  1. Can not be used to lock your bike to large objects (like trees, street lights...)
  2. It is pretty expensive

enter image description here

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    Couldn't you cut it with two bold cutter cuts? Seems possible to cut with bold cutters. Also skeptical if it is harder to cut than a Kryptonite lock. Commented Nov 24, 2012 at 16:32
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    There are demo videos on the site. They show bolt cutters of all sizes and cutting wheels. They compare Kryptonite to titanium. It shows a tiny nick with a 6 foot bolt cutter, which takes 2 people to carry. It simply can not be cut that way. You can grind through it, but it takes twice as long to cut as a kryptonite lock. AND that time was for the titanium held in a vise. It's way harder to do free.
    – Gary E
    Commented Nov 24, 2012 at 21:31
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    Here is a video of a TiGR lock being cut with bolt-cutters: youtube.com/watch?v=kb8YoT9Q9VA. Commented Oct 12, 2014 at 18:06
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    @brannerchinese Impressive - thank you for showing how poor that lock is.
    – Criggie
    Commented Jun 16, 2016 at 20:49

Two suggestions for securing your wheels, seats and components:

  • Pitlocks are locks that will lock your wheels and seat in place. I have never used them before but they seem like an interesting solution.
  • I have also heard of people locking in their components by dropping a ball bearing followed by hot wax into the allen screw. This makes it very difficult to quickly take off the components. To do so you need a long nettle or a lighter.

Die! Bike thieves!

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    It's common in London for thieves to remove the skewers - not to steal the wheel but so you have to leave your bike overnight, so they get chance to work on the lock.
    – mgb
    Commented Sep 14, 2010 at 15:33

In NY, there are many people, including me, with this lock. The one downside is its weight, ~6 lbs! I usually carry in a backpack or wear it around my waist(that's what the badass bike messengers here do...I'm not one of them. :) )

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    Is it just my locality, or is it common for people to leave a lock at their destination so they don't have to cart around the lock. Where I work, and all around my city, you'll frequently locks left on the racks with no bikes. Personally, I leave a lock at work, on the bike rack so I don't have to lug the lock back and forth to work.
    – Kibbee
    Commented Aug 30, 2010 at 15:36
  • I have the same one but just the lock - no chain. It will lock between the rear frame and one of the thin bike racks. It's too small to get a jack or pry bar in to break it.
    – mgb
    Commented Sep 14, 2010 at 15:31

I'm not sure if it is the best lock, but it certainly is more safe against lockpicking than many locks: The Forever Lock

See YouTube video and store. (and an attacking YouTube video)

Three locks I often read about when looking for secure bike locks are:

  • ~ $145, 1.6kg: Abus Bordo Granit X-Plus (Folding Lock; shop)
  • ~ $80, ~1.4kg: ABUS Granit X-Plus 54 (U-Lock; shop)
  • ~ $80, ~2kg: Kryptonite New York Lock (U-Lock; shop)

General lock type security

According to the German ADFC (source):

  • Cable locks are not secure even against simple attacks
  • Frame locks are not secure even against simple attacks - but they might be good to prevent the theft of a wheel.
  • steel-jacketed cable lock offer medium securit
  • chain locks offer medium security
  • U-locks are most secure - however, if you get the cheapest one it will still not be secure.
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    steel-jacketed cable lock are low security as you can cut then with most basic tools. Chain looks offer from low to high security it depends of chains and look.
    – kifli
    Commented Oct 6, 2016 at 7:51

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