Selecting a chain (or patching one)

[Skyguy9999]

Any advice on determining what kind of chain that is needed when it comes to replacing one?

[Alex Ramon]

1/8" chain is used on most single-speed bicycles, and bicycles with internal gearing.
3/32" chain is used on derailleur equipped bicycles that have more than 3 speeds.
9-10 speed cassettes take an even narrower chain. Harris Cyclery has some tips listed here: http://www.sheldonbrown.com/harris/chains.html