If you think about the sheer force that a bicycle chain must endure, it's an amazing feat of engineering and design. Truly, a bike chain is only as strong as its weakest link! The good news is, you rarely hear of a chain failure, and if you do, it will usually be due to misuse, rust, corrosion, or some other user-related error. By and large, bike chains are as solid a part of your bike as you'll find. There are chain tools which are meant specifically for taking links out of your chain, or for dropping your chain in the event you want to properly clean it. On that front, there are all sorts of contraptions which can be used as a chain cleaner, most often a box design that you place around the bike chain and fill with a liquid cleaner. When you spin your crankset, turning the chain, the chain is cleaned as it passed through the box's bristles and interior scrubbing brushes.
When it comes to chain sizing, you have to select your bike chain carefully. For instance, in the Shimano lineup of chains, the difference between a 9-speed and 10-speed chain is just 2mm of width. But you have to get the right size chain for your bike drivetrain setup. When you install a new chain, you can use a chain tensioner in order to make sure that you won't get too much chain sag once installed. You can also put a chain guard on your bike in order to protect your pants leg or shoelaces from getting caught up and chewed up by your chain when it rolls through the crankset.
One of the greatest chain innovations, in our view, is the SRAM Powerlink. This is a special link which you can use to remove a SRAM chain from your bike at the pinch of your fingers. Most SRAM chains are sold with this special link included. Gone are the days of pushing out a chain pin in order to drop and clean your bicycle chain, and then, having to buy a bag of 5 replacement chain pins in order to reinstall your chain. As well, it was always hard to be sure if you get that new chain pin in just right. With the SRAM Powerlink (or Superlink, or Gold Link), it takes just a few seconds to join your chain together and click it into place. There is a special SRAM pin remover tool which seems to be almost necessary with the newest SRAM chains, since that Powerlink special link can be hard to undo with bare fingers. All in all, the SRAM lineup of chains is a good one to look at for road bikes, tri bikes, and mountain bikes.
The most popular chains are: