A dirty chain appears black, that's nothing new, but I just now decided to wonder about it.
New drivetrain (read: chainring, rear cog and chain), no rain has passed, no dirt has been throwed yet.
Still, the (nearly new) oil quickly starts to contain some black particles.
When allowing it to dry up, it forms a black grit on the rollers.
Recently, and also the trigger for this question, I've read this:
https://www.cyclechat.net/threads/why-paint-aluminium.246783/#post-5564000
First, so far I was unable to find a source explaining aluminium oxidizing to black. Instead, silver/grey is mentioned. But in case, the only aluminium in the drivetrain is the chain ring so wear of that part would have to be the source for the black particles.
Second, those black particles, if they are from a hard/harder material (ie oxidation increasing the hardness), they would accelerate wear. Question then is, how hard.
Third, IF chainring wear is the origin, would a steel chainring not have such a / similar drawback?
And last, the steel chainrings I found, seem to be quite expensive related to alu ones. Yet, alu is more expensive than steel, which should mean the opposite?
New drivetrain (read: chainring, rear cog and chain), no rain has passed, no dirt has been throwed yet.
Still, the (nearly new) oil quickly starts to contain some black particles.
When allowing it to dry up, it forms a black grit on the rollers.
Recently, and also the trigger for this question, I've read this:
https://www.cyclechat.net/threads/why-paint-aluminium.246783/#post-5564000
This post links "black oxidized" to aluminium.Depends on the Aluminium alloy, some alloys oxidize quickly and you'll be covered in black oxidized aluminium every time you touch the frame.
First, so far I was unable to find a source explaining aluminium oxidizing to black. Instead, silver/grey is mentioned. But in case, the only aluminium in the drivetrain is the chain ring so wear of that part would have to be the source for the black particles.
Second, those black particles, if they are from a hard/harder material (ie oxidation increasing the hardness), they would accelerate wear. Question then is, how hard.
Third, IF chainring wear is the origin, would a steel chainring not have such a / similar drawback?
And last, the steel chainrings I found, seem to be quite expensive related to alu ones. Yet, alu is more expensive than steel, which should mean the opposite?