How do you replace a bicycle chain

This is how you repair a broken bicycle chain on the go

A chain break is one of the more unpleasant experiences in a cyclist's life. However, with the right tools and dexterity, a broken chain can be repaired quickly, as Bergzeit bike expert Flo Glott explains in the third part of his series of bicycle repair articles.

A beautiful summer day in Munich. Countless racing cyclists and mountain bikers whiz towards the south of Munich - be it on the Isar trails or on the network of side roads that attracts countless cyclists season after season. At a traffic light in Thalkirchen I step on the pedals - and suddenly into nothing. Something rattles behind me. My chain broke and is twisting on the road surface. What now?

Which tools do you need to repair a bicycle chain?

For riveting a broken bicycle chain, you need following tool:

  • Chain tool
  • Chain tensioner (is part of one or the other chain tool or multitool, otherwise a bent piece of wire / spoke will do)
  • ideally also a rag so that your hands don't get dirty

Quick guide to repairing a bicycle chain on the go:

  1. Put the chain back on: Before riveting together, thread the chain through the rear derailleur and derailleur - note the direction in which the chain runs. read more
  2. Remove the defective link: Insert the chain link to be removed into the chain riveter, turn it until the rivet spindle is in contact with the rivet pin (see Fig. 2) - almost, not completely, push the pin out. read more
  3. Rivet the chain together: Remove the defective chain link - bring the chain ends together and press them together - attach the chain tool and press the rivet pin back into the chain link. read more
  4. Make the chain link run: Check whether the chain link can be moved easily - if a kink is visible or the chain can only be moved slowly, bend the chain back and forth at the rivet point until it is easy again. read more

DANGER: It is essential to check that the chain tension is not too high after the repair - otherwise a new link must be used (see below)!

Change chain - that's how it works

1. Put the chain back on: With a classic chain break, you have either lost the chain or it has wrapped itself more or less elegantly around the cassette or crank. Before riveting them together, you have to thread them through the rear derailleur and derailleur. For this you should

  • Shift the rear derailleur and the front derailleur to the smallest blade
  • then thread the chain through.
  • Please also note the direction in which the chain is running. The labeled side of the chain should face you - at least if there is only one labeled side.

2. Remove the defective chain link: So that you can press out the head pin with the chain tool, insert the link to be removed into the chain tool and turn the rivet until the pin of the tool touches the pin, as you can see in step 2. If the pin of the rivet sits in the middle of the chain rivet, you can push it out.

DANGER: Do not push the head pin all the way out. This must still sit in the outer chain link with a slight protrusion, as can also be seen in step 2.

3. Rivet the chain together: Once the defective link has been removed, you can rivet the chain back together.

  • To do this, bring the two ends together and press them together. Because you did not push the head pin completely out of the outer plate, the chain should hold together by itself.
  • A well-equipped repair kit also includes a chain tensioner that holds both ends of the chain together during the riveting process - it can make the “riveting work” much easier.
  • Now put the chain tool back on and push the rivet pin back into the chain link until it disappears completely. If the chain is under too much tension, you can also place it from the small chainring on the bottom bracket housing.

DANGER: Be careful not to push the head pin too far into the outer tab. If in doubt, use the overhang on the other side of the chain as a guide.

4. Make the link free: After riveting, the links should be easy to move again. When the chain is tensioned, there should be no kink in the chain line, if you let the chain run through the rear derailleur to test it, the rear derailleur should not be pulled along by the chain. If this is the case, hold the corresponding link - as shown in Figure 4 - and bend the chain back and forth until the link is easy to move again.

A chain repaired en route should be replaced

You should definitely replace a chain that has been repaired several times on the way as soon as you get home. There are several reasons for this: On the way, you often only have the option of shortening the chain around the defective link. It is not always possible to insert a replacement link. When the chain is shortened, however, not all gears are available because the chain tension increases the more diagonally the chain is positioned (keyword: correct chain line!). If the chain has already been “on the links” for a few kilometers, more or less signs of wear can also be seen on the entire drive train (chainrings, chain, cassette). A link that has not yet been used ultimately no longer fits the rest of the drive train; In the worst case, the chain can slip at the point of the newly inserted link under load. The newer the chain, the more it makes sense to rivet in a new link in the long term.

TIP: Individual manufacturers such as SRAM and Shimano offer chains with a chain lock. A chain lock enables the chain to be locked without the need for chain rivets and chain rivets. Ideally, you should only use chain locks from the respective chain manufacturer - even if these are partly compatible with each other.

Conclusion on repairing a broken chain

Don't be afraid of broken chains! Like any other mechanical component, a bicycle chain can be repaired relatively quickly with the right know-how. Smaller TIP Finally: If you have a few "leftovers" lying around at home, you can practice riveting relatively easily - this is faster in an emergency.

Tool needed? Here you can find the complete selection at Bergzeit:

You're still looking for a suitable one bicycle- or MTB guide? You are sure to find something in the Bergzeit Shop:

More articles on the subject in Bergzeit Magazin: