How to tighten a bike chain
· Replace the entire chain. With time, the chain gets worn out causing the bike chain to get longer. In such a case, it is best to replace the entire chain with a new one. · Remove one or more chain links. A bike chain is made up of a series chain links that are joined together by pins. You can remove one or more links until you find the appropriate length and tension of the chain. · Replacing or fixing the derailleur. At times, a chain sag can be caused by a faulty derailleur. A derailleur that has lost its springiness will not create the effective tension needed to keep the chain tension optimal. In such a case, consider adjusting, replacing or repairing the derailleur. To adjust the derailleur, identify the point where the cable enters the rear derailleur. Use the barrel adjuster to tune the derailleur by turning the knob clockwise and anti-clockwise until shifting is smooth. The same technique can be used to adjust the front derailleur.