Why is chain length so important?
A new bicycle chain will tend to come with 116 chain links, each measuring an inch. This is so that it will fit even the biggest chainrings and sprockets. For touring bikes or single-speed bikes, this can change as you have either more need or less need for a chain of this length, however, this will make it easier for you to adjust your chain.
For most bikes, you will need to shorten the original chain to make it fit. This can be done by removing the link by using a chain tool to remove the stud or bolts from the chain when getting it to the right chain length. But it is also important to get the right length as if your chain is too long, you risk it slipping off of the chainset and damaging itself or your bike. Too short, and it could damage both your derailleur and groupset.
How do you get the right chain length?
Getting that right length is vital to a good ride. It means keeping your other components in top condition, and there is a very easy way to do it. This website will give you the right specification and all you need to do is give three measurements: the length of the chainstay, the largest chainring, and the largest sprocket. Easy. All of these measurements normally come within bike manuals for your ride, something you can usually find online too. Or if you can always use the chain already on your bike for an easy alternative.
Stretching it out
According to most estimates, you should change your chain every 2,000 miles but that can differ depending on which surface you are riding. For instance, if you clean your bike after every ride, spin your gears and weigh as much as a member of the peloton, you can get your chain to that kind of distance.
With that, a grand-tour rider will often go through two chains over the course of the three weeks. Although they do have the luxury of having a mechanic on standby after each day. For the rest of us, whether riding in cities or cold and rainy weather, the lifespan of your chain will be considerably shorter, and will stretch out over time, adding to the chain length. The easiest way to check this? With a ruler!
Grab your 30 cm ruler, the one you haven’t used since school, pull your chain tight so there is no slack and put the 0 cm marker in the centre of a rivet (chain link). If the end of your ruler also ends up in the centre of a rivet, then you have one healthy chain. However, if it is just 1.5 mm out, then it could be worth looking into getting a new chain. As mentioned above, chains are a hugely important part of your cycling experience and it is important to keep them clean, well lubed and in a good condition. This will keep the whole drive train singing for longer.
The We Love Cycling magazine has got you covered, giving you the best tips on how much you should spend on a new chain and we also go more in-depth on those key things to spot when your chain is wearing out.