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Fork oil is BLACK

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Yup, those Red Sachs CC forks are surely not hard anodized inside......!

It was waaay past time for a service, and another valving tweek.  I've been loosing weight, and riding more aggressively lately.

New bushings, fork seal (one is leaking).

Brian at N2Dirt is the Doctor in Residence.

Hopefully, a test ride on Sunday....

 

Should see the '19 480RE in about 6 weeks !

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You know what to do, and you likely still have the shipping address. 

They aren't going to heal themselves ...

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Is the black mostly due to aluminum oxide forming on the aluminum component surfaces and tainting the oil, or is it a result of wear?  Of course, no matter where it came from, aluminum oxide suspended in fluid would quickly accelerate wear.  I frequently pull apart KYB forks with heavy wear that are decades old, and I don't see that kind of dark oil -

Could it be that they are using a more reactive aluminum alloy for their forks?

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7 hours ago, kawagumby said:

Is the black mostly due to aluminum oxide forming on the aluminum component surfaces and tainting the oil, or is it a result of wear?  Of course, no matter where it came from, aluminum oxide suspended in fluid would quickly accelerate wear.  I frequently pull apart KYB forks with heavy wear that are decades old, and I don't see that kind of dark oil -

Could it be that they are using a more reactive aluminum alloy for their forks?

This has been covered. The Sachs CC forks have sub-standard aluminum treatment to the uppers.

A 'trough' of wear develops if you do not shim the bushings and rotate the uppers.......or of course, having them hard coated would be ideal.

You have to also remember, the terrain I ride is very rough, and I am very tall and big, which does not help the forks.... this oil is probably 50+ hours old.....

The 2019 forks have supposedly addressed this issue, and much more.

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The fouling would be a combination of the anodizing(harder) being worn off, plus the soft base metal underneath.   What happens then is the cartridge walls also start to wear from the fouled oil migration, and contribute.  Its a cascade effect.  Also, but not relative to the issue, there is usually some normal/light steel contamination from the spring/tube interface. 

As I said before, IMO this issue is a combination of things, not just poor anodizing, although a good T3 coating WILL take care of it.  I have a set of KYBs  with around 300  hours on them, ridden very hard.  I have already had Steve hardcoat the cartridges because they just wore out.  The uppers are fine, in great shape.  Production Yamaha KYB SSS from the YZ250F doner ARE NOT T3 hard coated.  There is much more in play here, from engineering, manufacturing, and user variables.

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3 hours ago, GP said:

.. I have already had Steve hardcoat the cartridges because they just wore out........

 

Cartridge rod?

Cartridge tube?

Whole cartridge?

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Cartridge tube inner wear.  Rods were fine and still are.  I'll likely do the rods and uppers this winter simply because of age.

Don't neglect rebound piston bands. Don't just look, MEASURE them.

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15 hours ago, WILLY THE WORT said:

It was waaay past time for a service,

How many hours on that oil?

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4 hours ago, WILLY THE WORT said:

this oil is probably 50+ hours old.....

That's about 30 hours too long? Or more than twice the normal span?

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1 minute ago, Bermudacat said:

That's about 30 hours too long? Or more than twice the normal span?

That's an example of what I mean by a user variable.  Way too long, but in this case considering the forks history of coating failure with far less hours, its not a primary cause.  Likely that oil was black at 15 hours, but all the extra time didn't do the other parts any good. 

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So are you gonna get them coated?

or just seviced and let the next guy deal with it???

With all the aerospace in so cal getting some coatings done shouldnt be a big deal. I like embee plating down in santa ana right around the corner from uptite...

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39 minutes ago, surfer-dude said:

So are you gonna get them coated?

or just seviced and let the next guy deal with it???

With all the aerospace in so cal getting some coatings done shouldnt be a big deal. I like embee plating down in santa ana right around the corner from uptite...

:facepalm:

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1 hour ago, GP said:

That's an example of what I mean by a user variable.  Way too long, but in this case considering the forks history of coating failure with far less hours, its not a primary cause.  Likely that oil was black at 15 hours, but all the extra time didn't do the other parts any good. 

I will do my best to be at the opposite end range of the data set. :smirk:

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I've seen a fair few posts about this issue but still haven't been able to determine this--- Are the black OC forks on the 18 model being affected by this issue?
The brochure mentions something about "fork with new sleeves" so I'm hoping they are upgraded

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