Chain links allow you to join a chain and - in some cases - break a chain without tools.
They are useful for:
- Routinely breaking and making chains for cleaning - arguably the most thorough cleaning methods require you to remove your chain from your bike.
- Repairing a broken chain - particularly while out on a ride. Note that this will usually require a chain breaking tool as well.
If I buy a new chain that comes with joining pins, I always use a chain link instead. I also carry several chain links with me on a ride - just in case.
The following sections describe several aspects of chain links. Click any section heading to show or hide it.
Types of chain link
There are three main types of chain link:
- Reusable chain links - these are designed to be used to join and break chains multiple times.
- Use-once chain links - having used one to make a chain, you are expected to discard it if you use it to break the chain again. I've read scepticism about the need to replace (which might be justified) but reusable links come with a price premium - if all links were reusable there'd be no point in producing use-once versions. The issue seems to be that the retaining edge can be damaged when removing a use-once link meaning the link can come apart while on the road.
- Wipperman Connex chain links - are reusable chain links. They deserve their own category because they have been specially designed to make and break easily. They cost more than other types of link (unless bought with a Wipperman chain) but breaking a Connex chain link is genuinely easy to do without tools - you simply make a 'Z' shape with the chain link and slide the two halves apart.
You'll see that chain links are sold in 'speeds', for example: 10-speed or 11-speed. That refers to the number of cogs on your rear derailleur. The more the cogs, the smaller the spacing between them and the thinner the chain - therefore, the thinner the chain link.
In the final section 'Other types of chain link' I describe a 'Master link' which is sometimes described as "Universal". That was true some while back, but I wouldn't attempt to use one with modern 10- or 11-speed chains.
Telling reusable from use-once links
So, you've decided you want to buy a re-usable chain link. Great. But how can you tell that a chain link is re-usable or not. Should be easy - but it isn't. In practice, you'll need to take account of several clues:
- Package description - as long as you're buying a reputable product (Shimano, SRAM, Wipperman, KMC or similar) from a reputable supplier, the package description should be definitive. If it says "reusable", it is. If it is silent about reusability, it isn't.
- Chain size - if you have an 11-speed chain link, the chances are it isn't reusable (the major manufacturers seem to have decided that it isn't practical to produce reusable 11-speed chain links).
- Product name - we're now getting into murkier waters because names can be used interchangeably. As a general rule "lock" in the name implies a use-once link. If it's a Wipperman Connex link - it's definitely re-usable.
- Price - use-once links cost around £3 per link (two halves); reusable links come at a premium starting at around £6. Obviously it's still possible to encounter over-priced use-once links!
- Supplier's description - this should be accurate. Better, though, if you can confirm via the manufacturer's web site. Check the packaging when the link arrives.
- Purchaser comments - are, in my opinion, useless. You'll often see people saying links are reusable when they mean "I reused it and got away with it". That's not the same thing at all.
Adding a link to a new chain
Replacing an old chain with a new one and a chain link is pretty easy - provided you have a chain-breaking tool. My multi-tool has one and I've always got it on a ride - although I've only ever used it at home - so far!
This video describes the process of cutting the new chain to length and fitting it with a chain link. The process is the same for most types of link.
The fitting process is slightly different for a Connex link. This video shows how it's done (and how easy it is to break a chain that uses a Connex link).
Breaking a reusable link
In the previous section I included a video that shows how to break a chain that uses a Connex link.
For other types of link the process can be as easy as pushing the two halves of the link inwards (towards each other) while sliding the two halves apart.
In practice, I have found some links to be this easy, but others either very difficult or impossible to do this way. It's perhaps at this point you appreciate the difference between a use-once link and a truly reusable one!
The next section explains how to break a difficult link.
Breaking a use-once or difficult link
My favourite technique for breaking a chain is to use this method as advocated by Chris Juden when he was CTC Technical Officer...
Here’s a quick and easy, tools-free way of opening a chain link from CTC member and Chartered Mechanical Engineer Ian Sheppard.
"Have the chain on your largest chainwheel, with the quick-link to the front of it. Hold the crank and pull the lower length of chain forward one tooth on the chainwheel. Move the one tooth’s worth of slack up and around the teeth, so that the quick-link and one other link form a sticking-out 'V'. Tap the point of the V sharply with a something hard and heavy (a hammer is ideal but a rock will do) and the quick-link will slide open – just like that!"
I tried this method on several chains. Some links needed a little pinch first (or a sharper tap) and it helps to aim at the side of the link without a slot at that end, but if you do that it always works a treat! Ian assures us that there is no danger of damage to the teeth, because the chain is forced into their roots where they are strongest.
Fortunately, it's a lot easier to do than explain. I couldn't find a video to show the method - please let me know if you find one.
This video shows an alternate method using a bit of brake cable. I suspect one or two pairs of pliers might help the process. I would also simply take the chain off the front rings to relieve tension on the chain rather than using a broken spoke as shown.
Arguably the simplest - but most expensive - method is to use a tool designed to separate chain links like this one.
But where's the fun in that!
Other types of chain link
This type of link is called a 'master link'. I haven't used one, but Mike Skiffins writes:
It was the only one I knew in the fifties. Single speed or hub gears so it didn't need to be sloppy in the joint, and the spring plate was no problem being used again and again. I always slid the closed end over one pin, hooked one arm on to the other pin and used a screwdriver to lever the other arm over the head of the pin into the slot. Rules are that you have to have the closed end in the direction of movement - that prevents the open ends catching and possible springing out. It is too thick to work well on a derailleur as far as I know, but then I didn't have a derailleur in those days.
The other method I know about is to use a connecting pin. Definitely not reusable (although in past times they might have been). You also need a chain breaking tool to make and break a chain using a pin.