Looking for some maintenance advice.
I’m about to embark on some touring. I don’t have space to take more than one canned product. Is WD-40 what I need?
As I understand it from some research, WD-40 is by some magic both a degreaser and a lubricant. This is mysterious to me. In my mental model of chemistry, you degrease with detergent, not more grease. So now I’m imagining that WD-40 is a sort of “light grease” which dissolves “heavy grease”. Is that right?
So if I can only take one product, is WD-40 it? PS: If not, then what? Also, is there a generic name for it, or cheaper similar products to look for which do the same thing?
PPS: The consensus seems to be that WD-40 is not a miracle product, by which really I meant “a single portable product that can somehow de-gunk and lubricate” and is less risky than what I was doing before: using chain oil for the lubrication and dish soap for the cleaning.
PPPS: This question was asked in the best possible faith. I have been a cyclist for decades and always been curious about this product. And yet still I get downvoted. What is about social media that makes people so toxic and mean-spirited? It’s almost as mysterious as WD-40.
I am not at all an expert on bikes, I’ve always been told that you shouldn’t use WD-40 on bike chains, but I’ve never really dug into the details on that. And not for nothing my own bike is a belt drive so it’s not even relevant to me.
Every time WD-40 comes up you’re going to get a whole lot of regurgitated, half-right information.
A lot of people are going to tell you that WD-40 isn’t a lubricant. That’s wrong. It’s not a particularly good lubricant for most applications (I think I’ve heard that it actually makes a pretty good cutting oil for certain machining tasks in certain metals) and there’s usually going to be a better, more effective, longer-lasting lubricant you should be using instead, but it does, in fact, provide some lubrication. Rub a little bit of it between your fingers, feels slick and oily doesn’t it? That’s lubrication.
People will bang on about it being a water displacer. Know what else displaces water? Oil. Grease. Pretty much anything else that doesn’t mix with water.
As for being a degreaser, like dissolves like. Non-polar chemicals like oil and grease are generally miscible in other non-polar substances, so a lighter oil will help to thin out thicker grease so that they’re easier to clean away.
I believe it also contains some other more volatile solvents that also help with degreasing. This is part of how it does it’s water-displacing/rust-preventive thing. The oil is further thinned out with those solvents so it can coat the surface better and those solvents then evaporate off leaving a thin film of slightly thicker (though still pretty light) oil.
And being so thin and light, it makes an OK penetrating oil so that it can soak into the tiny gaps around seized-up bolts and such to lubricate them, and the solvents help break up any other dirt and grime in there to help break it loose.
Again, not a bike mechanic, take my advice for what it’s worth (not much) but WD-40 is probably just too light of a lubricant to use for long. In a pinch if I had a bike with a really rusted, gummed-up chain that I only needed to ride maybe a couple blocks to get home (and just walking it on throwing it in a car wasn’t an option for some reason) I personally wouldn’t hesitate to douse it in WD-40 and hope for the best until I get it home to properly clean and lube it.
My general DIY philosophy for WD-40 is "this will get things moving right now so that I can diagnose the problem or finish the immediate task at hand, then I need to run out and get the right oil/grease to do things properly.
Glad to see I’m not going mad. “Water displacer”? Any oil is a water displacer duh.
This was my hypothesis but you put it in impressively fancy terms so it must be right.
The stuff about other solvents makes sense too. Really helpful feedback, thanks.