Fork Oil Interval

[Willsmotorcycle]

Having checked the service manual for the change interval and not seeing anything, I thought to ask what you use to gauge when it’s time. I have about 20k hard miles on the oil since last change.

 

[billo]

I seem to recall 5k being spec'd for some bike I owned (Yamaha FZ1?) In any case, 20k is wayyy too much. I change my bikes every 5 and it's gray sludge by then.

 

[Obo]

A sure sign is when it's running out the seals.... ask me how I know.

A fork oil only change isn't really difficult, just time consuming.

If in doubt, change it out. It does get cruddy, plus it lets you inspect the bushes etc. if you do the full disassembly, drain, refill.

OEM fork springs? Good time to swap them if you wanted.... new springs or hey, emulators ($$)

 

[dduelin]

15 to 20,000 miles is the interval I use.

 

[Willsmotorcycle]

I seem to recall 5k being spec'd for some bike I owned (Yamaha FZ1?) In any case, 20k is wayyy too much. I change my bikes every 5 and it's gray sludge by then.

The last time I changed it was about the same and one was dirty and one was oddly clean. 5k seems a bit excessive, I would be changing it on the side of the road twice a year…

 

[Willsmotorcycle]

A sure sign is when it's running out the seals.... ask me how I know.

A fork oil only change isn't really difficult, just time consuming.

If in doubt, change it out. It does get cruddy, plus it lets you inspect the bushes etc. if you do the full disassembly, drain, refill.

OEM fork springs? Good time to swap them if you wanted.... new springs or hey, emulators ($$)

I went with race tech springs last change, emulators will be when I get another set of forks and send them out to race tech for the full Monty.

 

[W0QNX]

5 thousand for fork oil? My engine oil change interval is 10 thousand. Would you like to know how long my fork oil went? Probably not.

 

[Willsmotorcycle]

5 thousand for fork oil? My engine oil change interval is 10 thousand. Would you like to know how long my fork oil went? Probably not.

I’ll bite.

 

[W0QNX]

I’ll bite.

Once at 60,000 (from wheelies probably) but 262,000 for sure.

"2 sets of fork seals. Once below 60,000 and once at 322,000. Do the math, the fork oil was in there 262,000 miles and was working "fine" to me. The sliders also still looked good but I replaced them top and bottom parts at the 322,000 seal change. The forks were not worn (looked "fine") but I rotated them 90 degrees so they wear at a different area now. "

350,000 on the Black Pearl | Mileage MileSTones

What year is your Valkyrie? It must of been a good year? I bought my 98 (with 202K) new in April 1999. My 2000 model Valk only has 65,000 on it. It is being ridden by my youngest son. He rides every day. It had 13,000 on it four years ago. My 2001 model (all are Tourers) has just a tad over...

www.st-owners.com

 

[Sadlsor]

Fork oil more often than valve checks?
Are you using the ST for motocross, or... ?

 

[TerryS]

15-20,000km seems like a reasonable frequency for fork oil changes.

 

[billo]

5k seems a bit excessive

I change synth motor oil every 2k so.. maybe.

 

[Daboo]

Do a search on the Interweb. You'll find some like in this thread who change it frequently...and others that don't change it at all. Dark oil only means it is doing it's job and holding any "dirt" in suspension (oh...you could take that as a pun, even though not intended!). I'm of the same opinion as WØQNX.

Just out of curiosity, how often do we change our car's shocks? Or the unserviceable rear shocks on our bikes? Never? But isn't the oil in either of those going back and forth like our forks? If one needs changing...the others do too. Or, if those don't need changing...maybe my fork oil doesn't either?

I think changing fork oil is like changing my car oil every 2000 miles.

Chris

 

[RobbieAG]

I change the fork oil with every other front tire change - so maybe 16 - 20k miles.

 

[Larry Fine]

Fork oil? Fork oil?

 

[ST1100Y]

... I too wouldn't exceed 22K-miles ...

Fork oil deteriorates (mechanical) and gets contaminated with (some) water (and whatever gets drawn in at the fork seals)
Broken down oil causes increased wear on the bushings, if ignored even the fork bottoms...

 

[W0QNX]

I still have the bushings that I removed at 322,000 miles. If anyone buys some new slider bushings and can measure with a micrometer and a 1/4 dowel pin I'll measure mine and we will compare to see how much mine wore down. Just guessing I say not even .010".

But, I may get a big surprise. Anyone else have some real 0 to 1" mics? My 0 to 1" mic was calibrated accurate to tenth's many times when I was using them at work.

 

[SMSW]

There was another thread asking this question and IIRC the consensus was the same as posted above - 15 to 20K but probably no big deal if you go a few thou over the 20.

 

[Daboo]

I still have the bushings that I removed at 322,000 miles. If anyone buys some new slider bushings and can measure with a micrometer and a 1/4 dowel pin I'll measure mine and we will compare to see how much mine wore down. Just guessing I say not even .010".

But, I may get a big surprise. Anyone else have some real 0 to 1" mics? My 0 to 1" mic was calibrated accurate to tenth's many times when I was using them at work.

Once at 60,000 (from wheelies probably) but 262,000 for sure.

"2 sets of fork seals. Once below 60,000 and once at 322,000. Do the math, the fork oil was in there 262,000 miles and was working "fine" to me. The sliders also still looked good but I replaced them top and bottom parts at the 322,000 seal change. The forks were not worn (looked "fine") but I rotated them 90 degrees so they wear at a different area now. "

I shake my head in wonder as I read the repeated advice of posters who swear you need to change your fork oil at 15-20K. WØQNX's real life experience says he put 262,000 miles on his with no issues. He's put more miles on his ST than probably 10 people combined. I only had a BMW, but still, I put 107,000 miles on my F800GT and only changed the oil once...and then felt like I made a mistake afterwards. And I never changed the seals. I never pulled the forks off. And the bike felt great. (Well, as good as you can expect in the Seattle area's pothole filled roads.)

 

[Sadlsor]

Maybe so, I don't usually pull the forks or change the oil either, unless there is a problem.
But one thing has stuck in my mind about suspension, from RaceTech -- The best you've ridden is the best you know.
So there is a LOT of hidden potential in even ST suspension.
A rule at our office: You don't know what you don't know.