How to Make a DIY Bicycle Lock

Keep your bike from being stolen with the power of the Internet. Here’s everything you need to know to make a DIY bike lock.

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If you have recently got a bike and you’re trying to decide what lock to buy, you might be a bit taken aback by the prices you see online and in stores.

Good bike locks aren’t cheap—and cheap bike locks aren’t worth the money. So let’s look at how you can build one yourself.

You can make your own chain lock with a heavy-duty chain, a good padlock, and some rubber or cloth tubing. This is simple and relatively inexpensive, but be aware that chain locks can be cut by a determined thief.

No bike lock is a guarantee that your bike won’t be stolen. And it shouldn’t go unmentioned that some store-bought locks, such as a thick U-lock, can be much more secure than the do-it-yourself version.

With that being said, good locks cost a lot of money. And not every bicycle owner is willing or able to buy one. If that’s the case, a sturdy homemade chain lock can provide better protection than a cheap cable lock.

So let’s talk about how you can make one!

How To Make A DIY Bike Lock

Here’s how to make a DIY bike lock in three steps. Heads-up: You will need to plan a trip to the home improvement store or do some online shopping.

Step #1: Get the Supplies

To make your own bike lock, you’re going to need three things:

  • A heavy-duty chain. (The heavier the chain, the harder it is to steal, but you’ll also have to lug around more weight.)
  • A good padlock with a key or combination code.
  • A cloth tube or rubber sleeve that you can wrap around the chain to stop it from scratching your bike’s paint job.

Take some time in choosing the chain; both the length and thickness matter.

Thicker chains are harder for a would-be-thief to cut through, but they weigh more and they cost more, so you’ll need to factor that into your decision. Longer chains give you more flexibility when locking your bike up, but are also heavier to carry.

Related: What’s a Good Length for a Bicycle Lock?

You should make sure that your chain is heavy enough that standard bolt cutters can’t get through it, as this should be enough to deter most thieves. Many people recommend a 3/8″ Grade 70 chain, which is very hard to get through with bolt cutters, but not too heavy to be carried in most cases.

You should also choose a lock that suits you; if you hate fumbling with keys, opt for a combination lock. Preferably, one with four or five dials because it’s much harder for thieves to open. If you can never remember numbers, use a traditional lock.

Don’t forget the cloth or rubber tubing. Even if your bike is old, you don’t want the chain to scratch the frame and cause it to rust prematurely.

Once you’ve got these materials together, it’s time to make the lock!

Step #2: Wrap the Chain

The first thing you need to do is wrap the chain so it doesn’t scratch your bike when you use it. You can use any fabric or other weatherproof material for this job. Some people like to reuse old inner tubes.

Simply wrap the fabric or rubber around and around the chain, covering up the metal, but leaving a loop free at both ends. Secure the fabric with glue or waterproof tape once it is in place, and the chain should be safe to leave wrapped around your bike.

If you want to use an old inner tube, cut off the valve stem using a sharp knife or a pair of scissors, and then cut the tube down the middle. Open it out and wrap the tube around the chain, and then secure it. You will likely need several tubes to wrap a whole chain, although this does depend on the chain’s length.

The advantage of using an inner tube is that it will be waterproof, so it will also protect the chain from the elements to some degree. It will cushion the chain and prevent it from knocking against your legs or your bike as you cycle.

Step #3: Add The Lock

Choose whichever kind of lock would better suit your needs, and simply click it through the two loops of chain that you left unwrapped. 

If you’re going to use a traditional lock, it’s a good idea to have a spare key that you can store somewhere safe at home. If you’re using a combination lock, consider writing the combination down somewhere secure, but don’t keep it on the bike in case somebody else finds it.

You’ve now done everything that you need to in order to add the lock to the bike and you’re ready to go.

How To Make A Temporary Bike Lock

If you’ve been caught out and about with no lock, you might be wondering what your best options are for securing your bike. Note that none of these are foolproof methods so you should only depend on them when you’re in a pinch. Always try to have a proper bike lock available.

The first option involves using cable ties. They will not deter a thief who has access to a knife, wire cutters, or another tool, but they will hold up against an opportunist who is just going to grab your bike as they walk past. They are certainly better than nothing. If you have the tools, you can also take off a wheel.

Alternatively, try a bungee cord. Again, this will only work against opportunists, but it at least makes your bike more difficult to walk off with than if you leave it totally unsecured. Wrapping your helmet strap around the back wheel so it won’t spin could also be enough to put off an opportunist, and may delay them for long enough to make stealing your bike less attractive.

Another tactic involves deception; if you can make your bike look like it is locked up, it may not get stolen. Put it in the center of a bike rack, among other bikes, or in some bushes, where it’s hard to see the lack of lock.

Some people turn their bikes upside down to suggest they have been damaged and they are nearby, in the process of repairing them.

Related: How to Lock Your Bike Without a Rack

Conclusion

Making a DIY bike lock can be preferable to buying one, especially if you are on a budget and you live in a fairly low risk area.

If you live somewhere with a lot of bike thefts and you have a valuable bike, always purchase a proper lock instead, as a simple chain is not likely to deter thieves for very long.

By Dim Nikov

City dweller. Recreational cyclist with a knack for writing. Always trying to find the right balance between life and bike.