Chain tool

Once completely removed, chain pins are often very difficult to insert with a tool unless it has been specifically designed to do so.

Users may overcome this limitation of some tools by never completely removing a pin that they intend to replace.

They push the pin so that the chain can be broken, to shorten it for example, but so that it is firmly retained in the farthest plate.

They are connected by hand pressure but often need a pair of needle-nosed pliers for removal.

Bicycles with a single front chainring and rear sprocket (for example bicycles with hub gears or coaster brake hubs) may have a master link on the chain which holds the pin in place with an easily removable c-clip.

Some master links are bevelled on top, and can interfere with the smooth operation of a derailleur system.

A typical chain tool. With a chain placed on the central sprocket, the screw is turned until a pin is pushed from the linkage