Maintenance
When to use, and when not to use, a penetrating oil on your bike
Ibet every household in this country has a spray can of penetrating oil lurking somewhere, whether in a closet, basement or garage. The most common is probably wd-40. (It, however, is actually a water-displacement product, designed for getting rid of moisture.) Penetrating oils often find themselves pressed into service for various household jobs. If they can stop a door hinge’s squeaking, they could work for a squeaky chain, right? Actually, no.
I highly recommend that you do not use a penetrating oil as a chain lube. It will actually strip your chain of its lubricant. Spray it on a greasy part, and you’ll see. It does a good job of cleaning it. Why is this so? Many penetrating oils act more like solvents than lubricants. The solvent part cleans up the gunk on your door hinge, then the light oil part takes away the squeak. Your chain moves faster and faces more friction than a door hinge. If you use penetrating oil as a chain lube, it will dry out quickly. Your chain will be unprotected in no time. The only occasion you might use an oil with water-displacement properties on your chain is after washing your bike. This spray will get rid of the moisture and get the chain ready for an application of real chain lube. Make sure to wipe the penetrating oil off completely before lubing.
I’d also OK the use of a penetrating oil on your bike to loosen up a rusted bolt or seized seatpost. Since the spray can act as a degreaser, it’s actually great for removing stubborn grease stains on your frame and glue residue from race decals. If you do bring a spray can to your bike, be very careful. Don’t get the substance on braking surfaces, especially disc-brake pads and rotors. If you hit a disc pad, it will absorb the fluid immediately. The pad will be ruined, and you’ll have to replace it. If you ride the bike and apply the brake with an oil-contaminated pad, the rotor will also be compromised. You’ll need to clean the rotor thoroughly with a light emery cloth and alcohol. Try to avoid this situation.
The bottom line: do not rely on a common household penetrating oil as lubricant for anything on your bike. If you do need a penetrating oil for your derailleurs and mechanical shifting internals, I recommend Red Stallion or Tri-flow. After cleaning, spray down all pivot points on your derailleurs, barrel adjusters and cable guides to restore smooth operation. Wipe off any excess. You can use them to lubricate mechanical rim-brake pivots, but, as always with penetrating oils, avoid braking surfaces. Spray with care.
“It’s actually great for removing stubborn grease stains on your frame and glue residue from race decals.”