I don't have any chain oil right now, but I have some gear oil left over from working on my car. Would it be an effective chain lubricant? It's listed as 80W90, but reading the Wikipedia article suggests that that's not equivalent to motor oil viscosity ratings.

  • 2
    You're in Vancouver, BC. I'm pretty sure that chain lubricants are not difficult to acquire, and in fact easy to acquire. So, why do you want to use automotive lubricants for your bicycle?
    – user313
    May 29, 2012 at 21:19

7 Answers 7


Short answer: No, you shouldn't. Heavy oils attract too much dirt, grit and grime which will damage the useful life of your chain.

You need a light lubricant which will wick it's way into the internals of the chain, rather than simply coating the external portion of the chain.

A good Teflon carrier lube like the Finish Line Teflon works well, lasts a good while and doesn't pick up dirt when properly applied. Using something like that will extend the useful life of your chain.

Gear oil is too thick, and designed for a higher heat production than you get on a pedal driven bicycle. It relies on engine heat, and the gears moving at high speed to produce enough friction to reduce the viscosity of the oil enough to be thin enough to flow as a good lubricant.

It would be better than nothing, but hardly a good choice.

  • 7
    "It would be better than nothing, but hardly a good choice."
    – user313
    May 29, 2012 at 21:06

Short answer: yes, you can. I've been doing it for years and my chains are lasting very long compared to ancient times when I used other stuff. Only potential caveat is that it is not the cleanest oil you'll ever use, but neither are the similar, much more expensive "wet" oils in the market (namely FinishLine Green). One liter of gearbox will cost a few bucks and last for the rest of your life.

Long answer:

  • Who said motor oil is good for chains? ;o)
  • The owner's instruction manual from my former motorcycle (a Honda 200cc one) said explicitly to use gearbox oil on the chain. I suppose that either applications are similar (weather-exposed roller chains on two-wheeled vehicles), and if the oil is good for motorcycle, with larger torques and speeds, it should be good for bicycles too;
  • Looking at the heart of the problem, roller chains need fluid, high-viscosity lubricants due to high pressure between metal parts. That's what happens on chains, that's what happens on gearboxes too. That's why FinishLine wet is viscous, and gearbox-oils are viscous too. Motor oil has a different application (hi-speed, combustion-chamber exposure).

Hope this helps!

  • 4
    So many things wrong here. 1. Finish Line's wet lubes are not viscous for high pressure/high heat applications. They are designed to be a sticky lube that doesn't wash off in wet weather. 2. The application on a motorcycle chain is entirely different than a bicycle. For one, motorcycle chains don't change gears externally. They also move at much higher speeds (due to smaller cogs being driven by an engine) and the size an tolerances on a motorcycle chain are much larger.
    – zenbike
    Jul 8, 2016 at 10:52
  • @zenbike Interesting, but does it mean gearbox oil is a bad choice for bicycles? (I'm asking because I am not sure at all). Recently I have read this surprising paper that says: "On a perfectly clean chain in a laboratory environment choice of lubricant makes little difference to efficiency. The real value of lubrication is to fill the gaps that would otherwise be filled by dirt and grime – things that do increase friction and decrease efficiency. Lower viscosity lubricants maximise efficiency." Jul 8, 2016 at 13:37
  • (continuing on above) the same paper suggests somewhat subtly that a clean chain is more important than a lubed one. That is, a perfectly clean and dry chain could be better than a lubed, dirty one. But sure in real-world scenarios there are a lot of trade-offs: current efficiency, long-term efficiency (during a long ride), durability, "dirtyness" (staining clothes), maintenance efforts / time spent, etc. Jul 8, 2016 at 13:39
  • 3
    Yes, it does. With the exception of those few bicycles with gearboxes. You'll notice most modern chain lubes are not simply oil, since that serves little purpose aside from gathering dirt to the chain (since we don't ride our bikes in a lab). Oils are used in bike lubes for 2 purposes: first to carry a dry "lubricant" compound like flakes of Teflon into the interior of the chain's plates and rollers, and second, to coat the exterior of the chain with a light coat of corrosion resistance. Heavy oils serve neither of these purposes, and gather the dirt and "things that do increase friction".
    – zenbike
    Jul 8, 2016 at 13:43
  • 1
    Even if you ignore simple cleanliness, a "dirty" chain shifts poorly.
    – zenbike
    Jul 8, 2016 at 13:44

You can use gear oil if you want to, it will lubricate your chain. Some thinner motor lube will tend to spray off the chain when pedaling.

I did an experiment and used chainsaw chain oil on my own chain on my fixed gear bike. It did a good job of lubricating the chain. However, it tended to pick up a lot of dirt and grime. It was also much harder to totally clean off unless I used really harsh solvents (like paint thinner).

So, I'm going to recommend buying bike specific lube. It is easier to strip and re-apply using citrus degreasers or other products (simple green) and will not pick up gunk as quickly (especially dry lubes).

However, I'm not going to convince everybody. Chain maintenance is a religious issue and everyone has their own set of beliefs about how to do it properly.

Lot's of esoterica and info about chain maintiance here: http://sheldonbrown.com/chains.html

  • 1
    Note that chainsaw oil is bio-degradable, which motor oil is not. Chainsaw oil is meant to get on the chain, do it's job, and be sprayed away to be replaced with fresh oil. Leave it on the chain for a while, and it will loose its viscosity. That's not what I want for a bicycle chain. Motor oil will provide more lasting performance. Jan 22, 2019 at 20:18
  • @cmaster Biodegradable chainsaw oil (bar oil) is biodegradable. Conventional bar oil is not.
    – pak
    Sep 2, 2019 at 20:39
  • @pak You mean, it's legal in your country to use non biodegradable bar oil? In mine, it's not... Sep 2, 2019 at 21:15
  • @cmaster. Yes, it looks like we both made assumptions about the entire world.
    – pak
    Sep 2, 2019 at 21:57

If you have some automatic transmission oil around the garage, especially the newer transmission oil, that would be better than a heavy oil on the chain. The heavier oil will pick up and hold all kinds of dirt from the road. Even some Marvel Mystery Oil ( remember that red stuff you could use for anything around the garage? ), would work well on the chain.


Of course you can use gear oil on your chain. It's an extremely good high pressure viscous lubricant, and unlike engine oils, it does not contain detergent additives which make engine oil less resistant to water washout. And its not too thick - grease is used as factory lube on all new chains, and this is way thicker than oil and is an extremely good lube.

Yes, applying too much will attract dirt, but you can avoid this. Gearbox oil is my lube of choice - but with the following method:

-I thin it out 50% with paint thinners. This allows it to penetrate extremely well into every link and roller, and once dry, results in only a very thin application of the oil

-After lubing and running the chain through the gears for a minute or so, I give the chain a good wipe to remove any excess oil. Wipe again after the first ride.

I get over 500 km between re-lubes, and over 8,000km out of my chains with this method. And its dirt cheap.

  • 1
    What do you think "viscous" means in the context of oils ?
    – Criggie
    Jan 22, 2019 at 7:08
  • 1
    an extremely good high pressure viscous lubricant "high pressure" doesn't exist on a bicycle. Jan 22, 2019 at 13:03

I have use automatic transmission fluid (ATF), over the last 20 years, and it works. A Few drops of ATF can do magic on your bearings specially with the almost dry ones. Its not for a long term use, carefully use at your own risk. I usually put 2 or 3 drops over the new grease. And reaply once a month 2 drops on bearings. For the chain (pivots, calipers, pedals inside covers, etc) it can last over 3 months. With a clean chain apply and take the exceed with a towel.

Now I use the chain waxing tecnic is better for me, less cleaning.

You can Make a test, 2 drops on your bearings,(start with the pedals) be carefull when test it, because will fly like new ones.


Motor oil is as good as any other fantasy chain lubes.

What should be kept in mind is the motor oil is fresh and not leftover extract while servicing a vehicle. If the instructions are to re-lube (after cleaning) after every few rides, then there will not be a problem with motor oil even.

If one wants to keep the lubrication longer, the thicker the better. It however becomes heavier as time passes. so, clean more often the old lube and re-apply at shorter intervals. the motor oil gives quite a smooth ride.

  • 1
    Welcome to Bicycles @pedalpusher. It looks like you haven't taken our tour, so I encourage you to do it, and to read through our help center. Check out the sections on writing good answers. Answering questions is quite a skill. One aspect is to understand the question first, and in this case the OP asks about gear oil, not motor oil. Second, the answer you've given about motor oil will step on the toes of our chain lube aficionados, so you may see some incoming about that :-) Again, welcome!
    – andy256
    Jun 30, 2016 at 10:29
  • This answer is just plain wrong, in several regards. Jun 30, 2016 at 12:10
  • FYI used engine oil is carcinogenic. Not sure about used gear oils.
    – Criggie
    Jul 1, 2016 at 9:30

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