Originally Posted by
cyccommute
The thickness or thinness of an oil used for bicycle chains means little. The use of “wear additives” means little. Hell, I’m not sure that the use of any lubrication means much. Bicycle chains see little in terms of harsh conditions and really don’t demand much of the lubricant used on them. Use any oil that you want. It won’t make the chain last any longer than any other oil nor any other lubricant, for that matter. Nor will it make the chain wear out faster.
The only thing that oil use will make worse is the need to do constant cleaning of the drivetrain and most of the rest of the bike.
There are bonafide test results from objective laboratories of chain lubes that showed the biggest difference in wear was from those that had "anti-wear additives" (their words, I knew immediately what they meant, high-pressure additives). Oils without that are adequate, but the additives do reduce metal-to-metal wear, that's what they were designed to do in engines and transmissions where there is not a hydrodyamic bearing keeping things apart, like in the main bearings.
When I got to be a serious biker in my 30s, I thumbed my nose at dad's use of engine oil on the chains in my youth, but then years later, came to know that engine oil is actually a great lube for chains, and 3-in-1 oil not, specifically because of that difference. Bike chains experience higher unit pressure than you may think at the pin interface and between the rollers and "bushingless" projections.
Those same laboratories also showed the superiority of melted wax chain lubes, best with moly and teflon additives, but surprisingly, even plain 'ol candle wax was superior to oil, and you can't suspect bias there as no one makes money off that conclusion. I used melted wax for a decade on my road bike just for cleanliness, never suspecting that it actually prolonged chain life. (After 10 years and about 70,000 miles on that single uniglide chain, I saw the cogs had some cupping so reversed them and bought a new chain. I wasn't knowledgeable enough to periodically check chain stretch. But again, 70k miles, wax lube, one chain.) Go take a deep dive on Zero Friction Cycling if you want to see the data, test methodology, etc, it's pretty great.