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Steve698

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I know Honda have built this bike to a budget and generally speaking they have made a great bike but would it really cost so much more to install a small threaded bolt into the bottom of the fork legs to allow for oil changes without having to strip the front end down.

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I believe to get all the oil out you need to pump the legs, to do that in situ you would need to remove front wheel and top nut anyway, that then exposes the bottom bolt up inside the leg which can be used to drain the leg. Or of course the correct way is to drop the legs out so you can refill with the legs vertical and get correct fluid height set properly, does that really make much difference to the performance of the NC forks?

Edited by MatBin
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As the head bearings will need a re-grease, you may as well do the two jobs together. For a proper FULL service I like to strip the forks, remove the radiator,   check valve clearances while Iv'e got  plenty of room, then replace rad. new coolant, grease head bearings, replace fork oil and grease front wheel spindle. Easier than  doing each job separately.

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trisaki
7 hours ago, Rick said:

As the head bearings will need a re-grease, you may as well do the two jobs together. For a proper FULL service I like to strip the forks, remove the radiator,   check valve clearances while Iv'e got  plenty of room, then replace rad. new coolant, grease head bearings, replace fork oil and grease front wheel spindle. Easier than  doing each job separately.

Spot on  

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jeremyr62
On 11/29/2020 at 21:49, Steve698 said:

I know Honda have built this bike to a budget and generally speaking they have made a great bike but would it really cost so much more to install a small threaded bolt into the bottom of the fork legs to allow for oil changes without having to strip the front end down.

They stopped doing this years ago. In my experience getting those invariably seized bolts out was often impossible anyway, so even if my bike had them I wouldn't use them. Maybe the bike manufacturers came to the same conclusion.

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Johnnie Mototrans

Steve

I am with you on this one.

Old Honda fours certainly have this facility which I have used to change fork oil without dismantling.

There is plenty on the site about experimenting with different grades and quantities of damping fluids.

This would be so much easier if drain plugs were fitted.

 

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Defender
44 minutes ago, Johnnie Mototrans said:

Steve

I am with you on this one.

Old Honda fours certainly have this facility which I have used to change fork oil without dismantling.

There is plenty on the site about experimenting with different grades and quantities of damping fluids.

This would be so much easier if drain plugs were fitted.

Back in the '90's my air cooled XJ600 had drain screws in the lower fork legs, which I used to change the fork oil and refilled with the same quantity that had come out, which was approximately what Yamaha said should be in there.

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8 hours ago, Defender said:

Back in the '90's my air cooled XJ600 had drain screws in the lower fork legs, which I used to change the fork oil and refilled with the same quantity that had come out, which was approximately what Yamaha said should be in there.

Interesting you say that because all this "measure air gap" stuff is new to me, I used to do as you did, invariably if changing weight of oil it made a difference, otherwise they felt the same as before oil change. Seems to indicate my level of ability to tune suspensions. :)

I just ride them as they are and either crash through potholes or pogo along.

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Defender
22 minutes ago, MatBin said:

Interesting you say that because all this "measure air gap" stuff is new to me, I used to do as you did, invariably if changing weight of oil it made a difference, otherwise they felt the same as before oil change. Seems to indicate my level of ability to tune suspensions. :)

I just ride them as they are and either crash through potholes or pogo along.

It's a long time ago now, well over 25 years as my father was still alive, I seem to remember that the volume of fork oil was quoted in the replacement fork spring instructions, it may have been in the owners manual, but probably not?

What really struck me was that even though the was relatively new, less than two years old IIRC, when I drained the oil out, one leg was a dull red-ish and dirty, but the other leg was a nasty black colour with streaks in it!  Plus the fork top caps were a bit of a pig to get off too.

The next bike I did any work on the forks was my '98 Tiger 900 (Steamer), this time I had the forks off the bike and removed the springs and then hung the legs from the garage roof trusses to drain for a couple of weeks to make sure it was all out of it. 

I again followed the fork spring suppliers instructions which specified the volume of oil and the air gap, I did fill with the prescribed amount and measured the air gap at that was about right, within a mm or so.

I have my NC's forks to do, I may well do them over the winter when I won't want to ride it? 

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ChrisCB

Air gap is just a more accurate way to measure the correct amount in the leg, I'm just replacing the stanchions on my Varadero and the oil quantity and air gap are different left to right, 10mm gap and 17 ml of oil.

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Johnnie Mototrans

It does seem daft that most other oils and fluids can be easily drained and refilled yet forks require a substantial strip down.

Rear shocks are sealed units so let's not get me started on them.

Everyone that has claimed to have tried multiple different oils presumably did so at intervals of several thousand miles.

Forks are probably the only bit of the bike that you can experiment with different fluids without breaking something yet Honda make it difficult to do so.

So bring back drain plugs I say.

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Johnnie Mototrans
4 minutes ago, Chris750 said:

Air gap is just a more accurate way to measure the correct amount in the leg, I'm just replacing the stanchions on my Varadero and the oil quantity and air gap are different left to right, 10mm gap and 17 ml of oil.

I would be very wary of using different volumes of oil in each leg.

If both forks have been treated the same and filled with the same amount of oil.

The air gap measure is surely only a back up to show that everything is in order.

If it showed a difference i would pump the units repeatedly and if that still showed a difference i would start over.

 

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ChrisCB
6 hours ago, Johnnie Mototrans said:

I would be very wary of using different volumes of oil in each leg.

If both forks have been treated the same and filled with the same amount of oil.

The air gap measure is surely only a back up to show that everything is in order.

If it showed a difference i would pump the units repeatedly and if that still showed a difference i would start over.

 

The internals and the stanchions are different side to side on CBS-ABS Varadero's hence the oil capacity difference.

Edited by Chris750
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Yes not uncommon  different oil capacities left and reight even different levles  all sorts out there

Triumph used one leg compression the other regound at one point

Me I just look in the data prefer quantity rather than level but I lazey

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ChrisCB
12 minutes ago, davebike said:

Yes not uncommon  different oil capacities left and reight even different levles  all sorts out there

Triumph used one leg compression the other regound at one point

Me I just look in the data prefer quantity rather than level but I lazey

I have better tools to measure the air gap in MM than 538ml of fluid 😁

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Johnnie Mototrans
4 hours ago, Chris750 said:

The internals and the stanchions are different side to side on CBS-ABS Varadero's hence the oil capacity

Jings. I guess every day is a school day.

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Defender
12 hours ago, davebike said:

Yes not uncommon different oil capacities left and right even different levels all sorts out there.

Triumph used one leg compression the other rebound at one point

Me I just look in the data prefer quantity rather than level but I'm lazy

I'm well used to different amounts of oil in each leg, many mountain bike forks have been like that for donkeys years, there are even single leg forks like the Cannondale Lefty.

https://www.bing.com/images/search?view=detailV2&ccid=wlRHxv%2bE&id=90101B667CED87AC2967CDE294A24376ADE3B32C&thid=OIP.wlRHxv-EtDP-IZ3TSKqoqQHaFj&mediaurl=https%3a%2f%2fbikerumor-wpengine.netdna-ssl.com%2fwp-content%2fuploads%2f2018%2f05%2fCannondale-F-Si-Lefty-Ocho-Carbon_hi-mod-carbon-xc-race-hardtail-mountain-bike_single-sided-single-crown-100mm-fork-strut_World-Cup-front-angle.jpg&exph=1500&expw=2000&q=cannondale+lefty&simid=608050975961972949&ck=41B2D3DE5FF942FA341F35C9604712D2&selectedIndex=5&FORM=IRPRST&ajaxhist=0 

 

Edited by Defender
Punctuation.
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My cx500 Eurosport has slightly different oil volumes in each leg because the left one has an anti-dive mechanism in it called TRAC which was all the rage for a few years in the early 80’s. As far as I can tell they should have called it CRAP.

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My preference is air gap. I have a handy tool to use for this, with a syringe on it so I can remove any excess. It’s not Honda being el cheapo at all; I can’t remember the last new bike I bought that had drain screws.....

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