I do my spring maintenance on the family bikes throughout the winter to have something to tinker with.  Yesterday, after we rode on the trainers, showered and ate lunch, was dedicated to chains on the good bikes.  My Venge, and my wife’s Alias.

I use high quality chains for the good bikes.  A SRAM Red 11 for my wife, and a PC-1091r for me.  Why SRAM chains?  Simply because that’s what they carry at the shop.  I know, KMC makes a better chain, and yes, I’m fully aware I can save $20 online but I choose not to, because I want my local shop to stay open.  It’s actually a little tricky justifying doing the work myself in the light of that last sentence, but whatever.  I can live with it.  I LOVE tinkering on my bikes.

I get a full season out of the chain on my Venge because I take care of it so well, and that bike rarely sees a drop of rain, let alone a deluge.  My wife goes through two a year, but she rides her good bike through everything.

A few tidbits about chains:

1.  They don’t come in the right length out of the box – your chain size will depend on your chainset and cassette combo – they make them big enough to cover all of the combos, so you’ll have to trim a few links off your new chain.
2. You need a chain break tool for this.  I use a simple breaker on a cycling multi-tool (and an adjustable wrench or channel locks if you need extra leverage).
3. SRAM chains come with a connecting link that is only meant to be used once.  When used more than once, the opening stretches and they don’t hold as well.  If you’re one who likes to remove their chains for cleaning use a Whipperman  ConneX chain connector (and you shouldn’t need a tool for this one).  SRAM’s links do fail if you reuse them (I don’t worry about once or twice, but more than that, no way).  It happened to me on a chain I used to take off every time I cleaned the chain, 15 miles into a 100 mile ride, downshifting from the big ring to the little to climb a hill.  Boom.  Slack.  Just like that, the link popped.  My friends rode away (after I called SAG) as I was looking for the other half of the link.  I did, miraculously, find it and caught them at the next rest stop.  KMC says you can reuse theirs two or three times before they need replacing.
4. You want to replace your chain before they’re really sloppy.  Waiting too long will round out the cogs on your chainring set ($85 – $275) and your cassette ($35 – $310).  If you want to get every last second out of your chain “because the man is lying to you about how long they last to get you to buy more chains” (at $30 – $75, ahem), well go right ahead and use ’em till they brake.  While you’re at it, replace the chainrings and cassette, though, because now your shifting will skip when you put a new chain on if you don’t.  It’ll skip because you’re a knucklehead.
5. Buy a chain checking tool and use it.  
6. A new chain will shift crisper than a worn out, dead one… unless you let it go too long, then see #4.

So, to change your chain quickly, assuming your old chain was the right length, use a pair of chain pliers to remove the chain and set it down on a 6′ long stretch of paper towels, so it’s straight from one end to the other.  Take your new chain and set it down next to the old, lining up the links.  The new chain will be slightly shorter because the old one stretched out with use, so with your pointer finger, count each link together on the old and new chain till you get to the end of the old.  Then make a bend in the chain.  Remember this; you’re going to want to break the new chain so the outer plates go away.  I always go left to right, so the inside plates on the left, outer plates on the right at the bend.  Use your chain tool to break the new chain.  Clean the chainrings, cassette and jockey wheels, shift down to the smallest cog in the back, and install the new chain with the provided link.

If you screw up and break the chain at the outer plates, you’re going to have to push the pin back in using your chain tool.  Doing this is very bad.  If you don’t get it just right, your chain could fail on you.  If you do get it right, though, you’ll probably be fine.  I just took a chain off that I changed whilst hungry (not recommended, ahem), thus breaking the chain a half-link short.  You’ll have to get the old pin started in the hole to get everything lined up and back in the chain too.  You can press it in with channel locks or needle nosed pliers (this is not easy).  You just want to get it in there far enough it won’t move when you put everything in the chain tool.  Once you’re satisfied everything is lined up, crank it down and run the pin back in.  Don’t run it too far, either – you want the pin to set EXACTLY like all the others.  The important word in that last sentence is exactly.  Make it so… and hope for the best.  It worked for me, though pro mechanics will tell you to get a new chain.  It’s up to you, but I’m WAY too cheap for that.