Originally Posted by
DaveSSS
I'm just a lowly mechanical engineer who's who's been riding bikes and wrenching on them for 25 years. I've been using homebrew wet lubes for the last 10 years and I get better chain life than 90% of those who post on this forum. My regular homebrew is a 4/1 mix of mineral spirits or naptha and synthetic motor oil. I used a Campy chain with that lube for 6,000 miles and measured 1/16" of elongation over the entire length of the chain - not 12 inches. That blows your theory that wet lubes attract dirt and cause premature wear. A Shimano or KMC won't perform that well, however. Shimano in particular, will elongate at least four times faster than a Campy chain, with the same lube.
The popular ProLink chain lube is nothing but a mineral spirits and oil wet lube. Most shops sell a 4-ounce bottle for $6-8. I can make the same thing for 8 cents.
I don't ride in the rain since it rarely rains here in the Denver area, but I never intentionally rode in the rain when I lived in the Kansas City area either. I do ride where it's dry and dusty, with plenty of grit for that wet lube to pick up.
WD-40 has about the same percentage of oil as my regular homebrew. I know that the oil isn't very heavy, but it really behaves about the same as my homebrew. I do relube my chains frequently and wipe them down before and after lubing. I suspect that the greater reason for premature chain wear in infrequent lubing. A factory rep from ProLink actually advised me NOT to relube unless the chain started squeaking. Just what I want, a chain that starts squeaking after 10 miles into a 50 mile ride. No thanks.
When I get done with my chain wear test and find little difference between WD-40 and 80/90W synthetic gear lube, will that change your mind?
FWIW, the lubrication expert who posts on this site doesn't have much good to say about dry lubes.
I have no argument that home brewed lube isn't great and as you said, it uses a heavier weight oil than WD40 which is what we used to use as the solvent in our home brew... that worked great but was a little pricey.
You have not blown my theory away at all and should know, as a mechanical engineer, that when you are designing a system with an exposed chain drive that the lubricant used will have a great affect on how much dirt and dust can enter the system.
Oil is viscous... sticky... it likes dirt.
In designing that system you also need to account for a wide range of users and environmental conditions and when you do that, WD40 fails. If it was that good a lubricant we'd see it getting used in many more applications... but we don't.. because it isn't.
If I saw that it was better.. it would be the only lube I used for myself and in my shop.
Experience has shown me otherwise.
When I teach basic maintainence classes I explain that when you are lubricating a chain you want to use a minimal amount of quality lubricant and wipe away any excess as the chain does not need to be lubed on the outside and that excess lubricant attracts / catches dirt and will significantly reduce the chain's life.
We live in a very dry and dusty place.
Have you ever seen a bike with an enclosed chain case and do you know why the chains on these bikes last longer than any other chain ? It is because the system is closed and water and dirt do not enter the system. The chains aren't Campy either.
When you are doing this test try exposing yourself to a little moisture to reflect real world conditions too.