My bike was starting to squeak a little bit. It seemed to be coming from the axle of the front wheel. I haven't done much in the way of maintenance to the bike since I spent a few days last spring dialing in the three speed hub, so I determined a little bit of oil wouldn't hurt, provided I use it sparingly and in a limited number of locations. I didn't have any special bicycle oil. What I did have was an empty can of household oil, made for sewing machines, hinges, etc. and it had a nice plastic dropper on it for easy application. I also had about three quarts of 20W-50 Castrol motor oil on hand in a five quart container. So, being the problem solver I am, and necessity being the mother of invention, or in this case, refilling, I carefully transferred about an once or two of the motor oil into the empty metal can with the dropper.
Since it was after dark when I decided to do this, I wheeled the bike into my workshop and turned on all the lights so I could see better. Next, I turned the bike upside down and rested it on the ground on its handlebars and the seat. I have to be careful doing this, because the rear taillight on the rear fender stands a good chance of being damaged if I am not careful. This is because I first raise the front wheel like a wheelie, and just keep pulling it on over.
I applied a drop or two of the oil to the front axle, the rear axle, and tried to place a tiny drop on each of the joints of the chain, although the chain looked fairly lubricated. I'm sure it was my imagination, but when I left a few minutes later to attend a meeting in town, it seemed like the bike rolled easier, and the squeaking stopped.
The point of this is that I have every confidence that just about any bit of oil you might happen to have on hand will be fine for lubricating your commuter bike. Don't be afraid to use kitchen oil for that matter, most everyone has a little of that around. Use it sparingly. A drop of oil spreads greatly. You don't want to make a mess of oil on your chain and the moving parts of your bike, because it will attract dust, or your clothes will get in it and get stained.
You don't have to spend excessive money buying "special bicycle oil". Just dip a cotton swab (a q tip) into a small amount of cooking oil: canola, vegetable, olive etc.and rub it on the target area. Use a small kitchen measuring cup to hold a small amount of the oil , like a tablespoon to start.. You'll want that separate container to pour the oil into because the q tip will collect old, nasty goo from off the target area and it will corrupt the good oil when you dip it back into the clean oil. Better to corrupt a tablespoon of oil rather than the entire bottle.
If the q tip doesn't seem effective, I've used a toothpick to dip into the oil, because it will collect just enough on the toothpick to form a drop on the end, then you can place the drop where you wish with some accuracy. If you wish to take a little bit of precaution for overspray, you can use the aerosol cans of cooking oil. To prevent some uncontrolled overspray, rip off some cardboard from a cereal box, a twelve pack pop or beer box, or pizza box; even a paper plate. Hold it on the opposite side of the target area you're spraying to catch the overspray so it won't get on your floor. Again, use this oil sparingly as well.
Kitchen oil is not ideal for lubricating your bike. There are better choices. But, if you're a die hard bicycle commuter, you must acknowledge you, to some degree, value practicality. When you need to lubricate your chain and you don't have any oil designed for the purpose, or you don't want to get any for some reason, and you have some kitchen oil on hand; use the kitchen oil.
Kitchen oil won't work well to lubricate a badly rusted chain. To treat a badly rusted chain, lubricate it with WD-40 or an equivalent. An equivalent to WD-40 would be any spray (aerosol) oil identifying itself as "penetrating". Any spray oil which says it will free rusty bolts will do. I recommend you apply this product liberally to the badly rusted chain taking precautions to catch drips and overspray. After applying the oil generously, use a rag to wipe off excess oil in an attempt to reduce the mess of oil attracting dirt and dust. Ride the bike a day or two for ten miles or so. Then, sparingly apply the other lubricating oil. The penetrating oil will free up the chain and defeat the rust when combined with movement. The lubricating oil will help protect and lubricate the chain.
Because ideally you want to have your chain well lubricated, it runs the potential of leaving oily marks upon your pants or leg, or whatever else with which it comes into contact. That's why it's important for the bicycle commuter to ride a bike with a practical chain guard. The chain guard serves two purposes: it protects the clothes; and it protects the chain. If you're a dedicated bicycle commuter, weather conditions will seldom dissuade you. Protect the chain from moisture and grime and it will extend its life, and will increase your pleasure and performance on your commute.
Make sure you don't apply any kind of oil to the outer rim or wheel. Doing so runs the risk of the oil coming into contact with the brake pads. Brakes don't function as well when they encounter oil and your ability to stop will be adversely affected. In other words you won't be able to stop in as short of a distance. It will take a greater distance for you to come to a stop.
Good luck. Send me a comment if I can answer any questions for you.
Keep on commuting by bike!