The first thing we need to clarify about lubing a bicycle chain is that all chain lubes are not created equal.
The second is that, to my knowledge, there exists no “one lube fits all conditions” lube on the market.
Back in the day when I started riding a bike, more than 40 years ago now, oiling a chain was pretty simple. You squirted some 3 in 1 oil (or, God forbid, WD-40) on the chain and called it good. Those days are thankfully in the past because today’s equipment is much lighter and a lot more expensive to replace. A great place to start, to ensure longevity of major bike components, is the proper lubing of the chain. First, the chain will last longer. I regularly get between 4,000 and 5,000 miles on a chain – checked with a chain measuring tool, I don’t wait for skipping and noises to signal a need for a new one – where normal recommendations are for a new chain every 1,600 miles or so. Second, all of the components that drive the bike will last longer (jockey wheels on the rear derailleur, cassette sprockets and chain rings). To put this in context, a good lube will cost ten bucks for a year’s supply. A chain costs $30-$40. Jockey wheels are cheap but a cassette runs $35-$120. Chain rings can run anywhere from $65 to $300 and consider that those chain rings are aluminum, not steel, like the chain (a softer metal).
The proper lube for your conditions.
I ride, regularly, three bikes.
I have my good bike that rarely sees a drop of rain, let alone adverse road conditions. That chain gets a wet lube. Wet lubes aren’t useful in sandy, dirty, dusty or wet conditions. I use Finish Line Ceramic Wet Lube. It’s quiet, light, loose and fast. It also attracts dirt and washes off in a good rain.
I have a rain bike – a bike that I pull out when there’s more than a 25% chance of rain while I’m out riding. This bike, because it will be used in adverse conditions, gets a dry lube – Boeshield T-9. A drop is applied to each roller of the chain and allowed to dry overnight. This lube holds up in a rain storm and because it’s a dry lube, it won’t attract near the grime the wet lube would. This is also the lube I use on the moving pivot points on my derailleurs. I also use T-9 on our (my wife and my) tandem.
Then comes my mountain bike. This bike gets pummeled. Mud, dirt, snow, rain… It gets everything thrown at it. For that bike I like to alternate between the T-9 and Finish Line’s Ceramic Wax Lube, depending on my mood.
Now, to clean my chains, which I do as needed depending on conditions or every 300-400 miles whether needed or not, I use a couple of different techniques. I never apply new lube over old without at least a cursory chain cleaning. The Ceramic Wet Lube is simple: A wet, dish soapy rag, wrap it around the chain and spin the pedals backward while holding the rag tight around the chain. While continuing to work the pedals backward I wipe down the jockey wheels on the rear derailleur. Next I shift to the smallest chain ring at the front and clean off the big ring (I rarely use the little rings so they don’t get “dirty”). Once the chain is clean I take the rear wheel off and clean in between each sprocket on the cassette. Put everything back together and after letting everything dry for an hour or two, I apply new lube to each roller.
For the dry lubes, it’s a little more labor intensive. A wet, soapy towel won’t cut it. I take the chain off, soak it in degreaser, then wipe it down (all of my chains have a Missinglink and I have tool that makes pulling the link apart a snap). Once every other chain cleaning (or when the chain has dirt or grit on it from riding in the rain) I like to take an old toothbrush to it to clean in between the plates of the chain. Not entirely necessary but it beats replacing chin rings, chains and cassettes. For a quick clean up when I don’t have the time to do it right, I use Finish Line’s Spray Cleaner and Lube… Spray it on the chain, wipe it off, give it a minute to set in/dry, relube. Ten minutes.
Don’t take my word on my choices, they’re simply based on what my local shop stocks and recommends (and about 30,000 miles of experience). Try different lubes and ask what the folks at your local shop recommend. The conditions you ride in dictate the lube you use.
And remember: WD-40 is only good for loosening rusted bolts, stopping squeaks in door hinges and use on ultra-cheap production bikes that one would buy at big box stores. It doesn’t belong on a bike that you plan on using for years to come… unless you’ve rusted some bolts.