Chain Often Came of Your Bicycle?

Sometimes customers come to the shop asking us to help install their chain which had fallen off their bicycle. That can be fixed by adding a master link or rivet.



If the components on your drivetrain are worn out, it would be best to change them if you are installing a new chain, especially, if it is an expensive one. This is because each time you ride and change gears, any worn out parts on the drivetrain, such as, the freewheel/cassette or chainrings or derailleur wheels will pull and rub against the new chain. Your new chain will be damaged and you will have to change it sooner than it should.

If the mechanic informed you that the cassette needs to be changed too, it is possible that the teeth on the cogs of your cassette are damaged. If you do not change it, the chain will keep skipping over the top of the cog and fall off. Ask the mechanic to show you where the damage is. If you cannot see any wear, or burrs or bents on the teeth, you can always send your bicycle to another shop for a second opinion.

The following are some questions a good mechanic should ask you before re-installing your chain:

1) Is it a new chain? New chains for bicycles are always longer than needed. A chain that is too long will slack and fall off the bicycle. We can use the old chain, if it is still on the bicycle, to determine its required length. However, if there is a slack in the old chain, it is possible that it has worn out, in which case, we will have to determine the correct length required for the new chain.

1b) If it is a new chain, did you get the right chain for your bicycle? There are differences in chains for single speed and geared bicycles. Bicycles running on higher speed need the narrower chain which is more expensive. The cheaper single speed chain installed on a geared bicycle can cause it to fall off the chainring due to its width and thickness.

2) Did you fell off your bicycle while cycling? If you did, we will have to check if any components on your drivetrain have been damaged or need adjustment. Your new chain will be damaged if there are bents in the chainring teeth or on teeth of cogs on your cassette.

3) Did the chain come off only when you change your gear? That will mean either the chain is worn out and need to be changed or that the gears need to be set. Chain wear or dirt on it will affect the efficiency of your gears. If that is the case, just putting the worn out chain back on will not help as the chain will fall off again when you shift your gears.

Before the mechanic put your chain back on, he will have to check it for bents or stiff links. The chain will have to be cleaned first if it is clogged with dirt. Once installed, the chain should be lubricated together with the components on your drivetrain.