Fork oil change

JoFoS

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Gotcha. I was hoping I might find time to 'swing by' wherever it is, as I hope to briefly come to SA soon.

Hi MZ5,
Now that I am in the office, I wanted to reply to your last message,
and when it opened on my PC I thought,
Wait, which picture are you referring to . . .

If you asking about the picture where "the Lion is chasing the Zebra on the bike",
that one I really have no idea.
If you are referring to my picture of the NC on the bridge with the lake in the background,
that one I took myself on one of the drives me and my son took to Hartbeespoort dam,
roughly about here
https://www.google.co.za/maps/@-25.7604002,27.8040878,21z

It’s about a 35 mile drive from my house, with a stunning scenery, some very sweet twisties and a very nice straight or two.

When are you planning on coming to ZA, is it for business or pleasure?
 

MZ5

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Sorry about that. I meant your sig pic; the one of the bike on the bridge. Thank you for sharing.
PM sent.
 
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potter0o

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Thanks for doing this dduelin. I worked with this and the manual to complete this today. Not terribly difficult but like any project you learn along the way. I was going to touch up the forks with bronze wool but couldn't find it for the life of me. I have seen it somewhere before...but couldn't recall which store. Oh well next time I see it I will just scoop it up. Drained oil was on the greyish side. I always find a way to make the job messier than it needs to be. My used oil system has a storage indentation for the funnel. I dumped the oil in the funnel before installing it in the opening...had to clean up a literal forkload of oil. Like most things I would could do it again better. Makes me think I might be able to do the fork seals if/when they go.
 

drstimpy

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Great write up, Dave.

If so inclined, a body doing this job could fairly easily install Racetech Gold Valve Emulators at the same time. The added tasks would be to remove the one bolt at the bottom of each fork leg, dump out the damper rods and drill some additional holes. Reinstall the rods. Assemble and adjust the emulator valves and drop them on top of the damper rods. Shorten the spring spacers by about a half inch (or whatver is the thickness of the emulator valves). Reassemble the rest as described by Dave.

Greg

If you do this, loosen the damper rod bolt at the bottom of the fork before you take the top cap off. The spring tension keeps the rod from spinning as you try to unscrew Allen bolt at bottom of fork.


Sent from my iPad using Tapatalk
 

T S N

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I am glad I saw this information, I changed my fork oil today and at 20,000 miles it was over due. The oil was black/gray with silver metallic like break in oil from an engine. I wish I had changed it at 5000 miles to get that nasty stuff out sooner.
Flushed twice with alcohol, then once with ATF, followed with fresh new oil.
 

MZ5

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I just changed fork oil and seals in my '96 Magna. It has ~5600 miles on it. The fork oil was atrociously ugly and gritty, despite no particular wear anywhere (including to the bushings). I think I've decided that fork oil changes are something that one 'should' do quite regularly.
 

670cc

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What with all the talk of nasty fork oil being changed, it makes me wonder: doesn't the same thing happen to the oil in a rear shock? With a non rebuilable shock, should we just expect to toss it out after 20k miles?
 

rippin209

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What with all the talk of nasty fork oil being changed, it makes me wonder: doesn't the same thing happen to the oil in a rear shock? With a non rebuilable shock, should we just expect to toss it out after 20k miles?
the theory makes sense and that sucks because they aren't cheap and I've got over 43k miles
 

Antarius

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What with all the talk of nasty fork oil being changed, it makes me wonder: doesn't the same thing happen to the oil in a rear shock? With a non rebuilable shock, should we just expect to toss it out after 20k miles?

I'm not sure on the specifics of the Honda shock, but I know for a fact that shocks which are rebuildable, without question call for a service. That service almost always includes new oil, seals, gas, etc. I can't imagine the Honda shock would be any different, but it's not serviceable so.... lol.
 

MZ5

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There's vastly less movement in a shock, but I suppose quite a bit less oil, too(?), so perhaps it's similar.

My OEM shock came out somewhere around 43,000 miles, and it was still working well and properly.
 

showkey

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The front fork bushings ( top and bottom) are the wear points and they tend to contaminate the oil as they wear.
Generic picture of the bushing wear:

image.jpg

The rear shock is not exposed to the bushing wear as it is not supporting the bikes weight at an angle like the front. The rear shock oil and air seals and shock rod are wear points from water, grit, rust and will leak over time.
 
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potter0o

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Much to my disappointment the right side fork seems to be leaking oil now around the seal. Any suggestions?

I noticed it when I was riding home from work. Front brake was spongey. Sure didn't feel comfortable with a spongey front brake. Seems like some of the oil got on the disc. Have taken the caliper off and and cleaned everything up with brake cleaner. Will put it back together now for a test tomorrow :(
 

dduelin

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Fork oil change today at 20,000 miles on the 2015. The fork has Cogent Drop in Cartridges that I originally set up with Golden Spectro 85/150 5wt oil set to 140 mm. Today I used Showa Honda SS-7 5wt which has almost identical properties.

150 mm is right at 16 oz per leg which is right handy as SS-7 comes in 16 oz bottles.
 
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eastbayandy

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Antarius

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My 2012 with 8.5k has tiny cracks in the dust cover. , but no leaking. Is this normal and is it a prelude to leaking? Is it a good idea to replace the seals and dust cover when changing the oil since you have it apart already? Oh, and thanks for the write up. I found this when searching for fork seals.
How to Replace Fork Seals: 8 Steps (with Pictures) - wikiHow
2012 Honda NC700X | Doin' Time | Motorcyclist

Your dust cover won't necessarily be a prelude to your fork seal leaking. The dust cover just helps remove gunk from the fork leg before it gets into the seal and gives it a chance to cause it to leak. Just keep riding it, if it starts to leak run a small piece of thin plastic up and around the fork leg into the fork seal to dislodge any material that might be holding the seal open -- if that doesn't work, that means your seal is done and it's time to replace. At that point, I'd replace the seal and the dust cover as well.

But, to answer your question, the condition of the dust cover does not really mean anything in relation to the condition of your fork seal. In terms of replacing them when you do the oil since you have it apart? You can, some would, but I am a firm believer in the ol "if it aint broke, don't fix it" rule. I've got 40k on my stock seals and they're still fine, and the fork legs are always coated in year-round gunk from every day commuting. When they leak, I'll replace them.
 

Ferndiego12

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Great write up with very good pictures. Many thanks...I recently purchase a 2012 NC700X and will probably need to change the fork oil soon. This write up will be very helpful. Thanks again...
 

Fred Harper

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This is exactly what I was looking for. Does not seem to appear in manual online and mechanic I know says it cannot be done without a complete rebuild. I thought that was wrong. Again thanks.
 

Jt105

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My guess is that Brake cleaner will wash out the old gunk and then evaporate and not contaminate the new oil.

JT
 
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