I've lubed a chain on my motorcycle a few days ago, but there's a dark thing keeps flinging all over the swingarm. I'm wondering what it might be? If it's the chain lube flinging all over, then why it looks so dark, the lube I put on the chain after cleaning it is light brown, and why it keeps flinging if I wiped the excess of the lube off after lubing? How likely that it's not the lube flinging but the engine oil that's somehow leaking on the chain?

Additional info: The chain and sprocket were changed couple of weeks ago, everything in the front sprocket area was cleaned. The lube I use is a spray can chain lube, sticky light brown consistency.

  • 1
    Engine oil would likely leak all the time - place some clean newspaper under the bike and let is sit overnight. If nothing accumulates, let the engine run for a while at idle. If droplets accumulate on the paper, then they are from the engine, not the chain. If the paper is clean, then the crud on the swing arm is from the chain (this is the more likely scenario anyway)
    – mike65535
    Jul 26, 2018 at 13:49

2 Answers 2


(A picture would give us a thousand words here, but I'll reply anyway.)

Considering the chain sits in the elements when ridden, I'd bet what you're getting is bunk buildup of road grime, dirt, dust, and what have you which has built up over time, but now that you've put new chain lube on the chain, the gunk has gained a slight liquid state using the chain lube as a carrier. Now that the gunk is mobile, it's now flinging itself everywhere as you ride.

To me you have three choices to make it stop flinging goo all over the place:

  • Break the chain and give it a thorough cleaning in solvent, removing any more gunk which might be in the links
  • Replace the chain with new, keeping it cleaner and better lubed in the future to avoid the same situation
  • Put up with it until its worked its course, where no more gunk will get flung

As far as it being engine oil, if you've only now just started noticing it since you've used the chain oil, chances are pretty good it's no engine oil. Not 100%, that's for sure, but figure the odds on it. If something new is occurring, always look at your latest behavior or change ... it'll usually point you right at the cause.

  • I forgot to mention (I now updated the question) that I changed the chain and sprockets two weeks ago and cleaned everything under the front sprocket cover. Before changing the chain and sprockets I severely overtightened the old chain, so I'm concerned if that had damaged the shaft and seal, which may now leaking engine oil onto the chain. The chain and sprockets are brand new, the lube is freshly put, but the gunk that's flying around is dark. I rode only 150 miles on this chain sprockets, and lube. I lightly wiped the chain after spraying the lube.
    – qwaz
    Jul 26, 2018 at 14:13
  • @qwaz - Have you inspected under the cover to see if it's leaking? Seems like a good approach to finding such an issue. Jul 26, 2018 at 16:41

I'll answer to the question you should have asked but didn't: how can you reduce the amount of the black dirt flying around?

There are huge differences between chain lubricants. Try a different brand of chain lubricant. Best chain lubricants are in a spray can. They are thixotropic. Do note that not every chain lubricant in a spray can is thixotropic, and those that are, don't usually specify the magic "thixotropic" keyword. If a spray lubricant is not thixotropic, it will work extremely poorly and fly around all the time.

If you spray a bit of a thixotropic lubricant in a small container, you will see it's that it is quite liquid. However, if you leave the lubricant to settle, it gradually becomes very thick and not so easy to flow. Now, if you stir the settled lubricant, it starts to become liquid again and will flow easily.

Did you remember to remove the excess lubricant from the chain immediately after applying the lubricant? If not, this could also explain the black stuff flying around. Note that if the lubricant is thixotropic, getting the outer layers away might prove a bit tricky unless you do it immediately after applying the lubricant, and some amount of some solvent applied to a rag could help you.

I'm not entirely sure if these hints will stop all of the gunk from flying around, as the lubricant needs to be somewhat liquid to not cause additional resistance. But, however, you should be able to reduce the black stuff flying around to a minimum.

Disclaimer: I have no experience of motorcycle chains, but for bicycle chains the thixotropic motorcycle chain lubricants work well. I presume they work well for their intended purpose, motorcycle chains, as well. Yes, I do use a motorcycle chain lubricant on a bicycle; most of the bicycle chain lubricants marketed are pure crap.

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