If you've been into our shop and have had your bike assessed, you might have noticed that we measure your chain with a nifty little tool: we are checking for chain wear or "stretch." Chains don't actually stretch - instead, the rivets wear out to give the impression of stretch.
A chain will typically need to be replaced after 1,000mi of riding, but this depends entirely on your riding style, weather, and maintenance (single-speed chains can last much longer than this). Typically, if chain is ridden more than 1,000mi, it will likely have elongated about .5% of the course of a foot of length (take notes, there will be a quiz afterwards). Usually the first symptom of a worn-out chain is skipping in some gears. Replacing a chain on a regular basis, and keeping it clean and well-lubricated, is the best preventative medicine for your bike. Not replacing a chain when needed, on the other hand, will result in additional replacement costs of freewheels/cassettes and chainrings.
If you want to learn more, here's a link to Sheldon Brown's webpage on bicycle chains.
How much, you might ask, will a new chain cost me? Installation of a chain a la carte is $10, but it's included in any of our tune-ups. The price of our chains is:
Single-Speed/Fixie: $10 & up
5-7 speed: $10
8 speed: $15
9 speed: $25
10 speed: $40
11 speed: you've gotta be kidding me, nobody needs that many gears!
Come by regularly to get your chain measured - it only takes a minute - or you can do it at home with your own chain gauge, which we sell for $25. You can also do this with a tape measure or ruler, and we'd be happy to show you how.