This is the longest lasting chain oil you can make.
I have tried all kinds of chain oil, only one lasted more than a week for me (only two weeks). When I went to a chemical forum they recommended using aluminum hydroxide powder in oil to make an extremely viscous lubricant, that's what is used to make sunscreen cream. This lube lasts several months for my low mileage commuting, about a thousand miles, unless you ride in a heavy rain.
Step 1: Ingredients
The formula is not exact, make it thinner in the winter, thicker in summer.
STP (w/zinc oxide) about 55%
Light machine oil to thin it out a little bit so It will flow better than the STP. About 25%
PTFE powder stirred in. It settles down to the bottom over time. About 15- 20%.
I clean my new chain with Naphtha solvent twice to remove all the factory lube before applying this lube (the chain should rattle when clean and dry). Then I heat the oil a little in an eye dropper bottle to get it to penetrate the chain in cold weather.
Step 2: Considerations
lube is best used only for road commuting.
Racers need something more temporary made of wax and PTFE. Spray on wax lube maybe easy to apply, but it will bunch up and leave the chain un-lubricated in just a few miles. You should clean it off the chain after every use.
If you live with silica dust on the roads, you will be better off with no lube at all.
If you are a dirt trail rider, use the wimpy sewing machine oil, buy it in bulk.
Motor oil has detergents in it, and was designed to thicken as it heats up. Not for cold weather.
In wet weather some bicycles, including my own need a fender between the tire and the chain.
If you want your chain to last longer, keep it enclosed like on Dutch Style Bikes. This may require internal gears also. But you may need to have one custom made for your MTB drive train.
Change your chain before the sprockets are worn. This requires a good chain gauge. http://sheldonbrown.com/chains.html
Step 3: Better Than Chains
I hate having to change my chain in winter. I think it is time for some one to invent a belt drive that uses a timing belt between your crank and cassette. You could crank a mid mounted motor then use a timing belt between the motor and the left side of the drive wheel. But that may be hard on the motor's bearings so you would need a second stage reduction. And may still need a fender to keep road crud off the belt. But at least you won't need chain lube.
More about chains here: http://commutercycling.blogspot.com/2013/06/bicyc...
Luna Fat Bike. Image courtesy of Electric Bike