Bicycles/Maintenance and Repair/Chains/Installing a new chain
Installing a new chain
In general a new chain comes with detailed mounting instructions. For Shimano 8 speed or more , chain can be shipped :
- With a preinstalled pin , that can be used to close the chain
- Without preinstalled pin, but with a special reinforced connecting pin
Important is for Shimano, and probably for many modern chains, to DO NOT reuse ordinary pins . It is explained here :  On modern Shimano chains you should push the original rivet out entirely and replace it with a special replacement rivet, reinstalling the original pin is likely to cause the chain to break at that point.