Honda fork oil

[Roadride 13]

Can anyone tell me if the genuine Honda fork oil is mineral, semi-synthetic or fully synthetic?

 

I am going to change the oil very soon and was going to go with Motul Factory Line 7.5W Fully Synthetic, but if the Honda fork oil is mineral, does the internals need to be cleaned out first or just drained?

[DWD 62]

Not sure what the oil is but I am thinking of changing the fork oil in my 2017 Integra and was wondering what forum members would reccommend. It has the SDBV forks.

[MKH 17]

Hello Roadride

My reply doesn't answer your question but it may direct the debate. I'm also interested in the outcome as I intend to change my bike's fork oil at some time in the future.

A quick Google search suggests the genuine Honda fork oil has a part number 08208-0010, see: https://www.amazon.com/Genuine-Honda-Fork-Oil-08208-0010/dp/B077XNLVHN

A Google image search for the product found this that auction site advert, see: https://www.that auction site.com/itm/255858633673

If you look at the image of the back of this pair of fork oil bottles it confirms the part number and gives a little more product detail. Selecting and hovering over the image with your mouse pointer in that auction site opens an enlarged image allowing easier reading of the print on the bottle. The print says the oil is developed by Showa and contains petroleum distilates. That last bit "petroleum distilates" hints that the fork oil derives from crude oil rather than purely being manufactured in a lab. Honda fork oil could be mineral or semi-synthetic, the latter generally being a blend of mineral and synthetic products. Disclaimer, the more I delved into mineral v semi-synthetic v synthetic oils the more confused I became, so I empathise with you. Here's to the debate continuing with a few enlightened fellows.

[jeremyr62 2,573]

In my experience, it wont make that much difference what you use. All the brands have different ways of measuring viscosity so don't expect 10W from Castrol to be the same as a 10W from Motul. Again though, I doubt you'd notice much difference even if you did put one brand in one leg and one brand in the other. If you want to make sure you get all the old stuff out, just suspend the fork upside down overnight if you are removing them. The viscosity of the oil changes with use but not massively. People change their fork oil and makes comments about how dirty and smelly it is it is as if this somehow impairs its function. It doesn't really. It's just flowing through holes in the damper rod. The forks on my S appeared underdamped from new in rebound so I have upped the viscosity to Castrol 15W but it's still hard to detect much difference.

[Xactly 5,436]

I agree with the above. Honda dealers don’t put Honda oil in engines when they service bikes and I doubt that they do so in forks either. Also, while I wouldn’t put oil of a different specification into the engine (or gearbox or final drive on bikes that have separate lubrication of these), I have often changed the viscosity of the oil in the forks. On basic, non-adjustable forks like those on the NC the manufacturer will set the viscosity to suit an average weight load. This might not suit an individual and how/where they (rough roads, fast etc). As for flushing and the potential adverse reaction between the remnants of mineral oil and the fresh synthetic, I don’t believe that is an issue. I doubt that the original oil is truly mineral, more likely semi-synthetic, which is formulated on a base mineral oil anyway. I just use a decent brand of synthetic fork oil and having done so for years on many different bikes I have never had any issues at all.

[Andy m 23,585]

Fork oil isn't heated like engine oil and certainly isn't meeting anything like a clutch in there, it's a more hydraulic type action. Just go thicker/thinner/the same as suits you.

 

Andy

 

[Steve Case 955]

One of my fork seals has gone so i will drop the forks and get the seals replaced, this is the ideal time to get the fork oil replaced.

Question is for a rider heavier than the average would it be wiser to stick to the nominal 10w or try something else.

Friend of mine went to a motul 10w and he believed the forks were better controlled. He is below the average weight rider though.

[jeremyr62 2,573]

11 minutes ago, Steve Case said:

One of my fork seals has gone so i will drop the forks and get the seals replaced, this is the ideal time to get the fork oil replaced.

Question is for a rider heavier than the average would it be wiser to stick to the nominal 10w or try something else.

Friend of mine went to a motul 10w and he believed the forks were better controlled. He is below the average weight rider though.

Did you try measuring your sag? If you are a lot heavier than average changing the springs, might be more beneficial. If you pump the fork they are supposed to return to their rest position without overshooting but the NC dampers are so basic that even with 15W oil in they still overshoot. I have YSS PD valves in my forks and different springs too. It makes a difference but It's not really worth it. The forks are good enough as they are. Experimenting is fun though.

[jeremyr62 2,573]

A simple way to see how much fork travel you are using (sag) is to just fit a cable tie around a stanchion and see how far up it travels in normal riding. You can mark the max travel on the leg by extending the fork as much as you can and measuring 150mm (for the pre 2021 X), or you can go for a ride and at maximum speed slam the front brakes on as hard as you possibly can (only joking but it will work...) and see where the cable tie ends up, and this will be close to your max travel.

[Steve Case 955]

Oh i can see that from the scum line round the fork leg, its around 2/3 to 3/4 of the travel.

[jeremyr62 2,573]

1 hour ago, Steve Case said:

Oh i can see that from the scum line round the fork leg, its around 2/3 to 3/4 of the travel.

That sounds OK then apart from the leaking oil.

[Steve Case 955]

I wasnt planning making any changes apart from possibly higher quality fork oil.

The NC is built to a price point and i've no intention chucking money at it to make it something it aint.

[bladder 14]

On 12/02/2023 at 22:52, Steve Case said:

I wasnt planning making any changes apart from possibly higher quality fork oil.

The NC is built to a price point and i've no intention chucking money at it to make it something it aint.

how did you go on with the different fork oil, 15w.

[Steve Case 955]

Actually stayed with 10w but silkolene, it is reasonable damping now and points to the original oil being beyond its best.

I had to change as a fork seal had gone, but i think i would have changed it anyway.

[Roadride 13]

OK, so I have finally got around to changing my fork oil and went with Motul Factory Line 7.5W and set the air gap to 120mm.

Been out for a test ride today and was pleasantly surprised at how much better the front forks were for soaking up the harsh bumps in the road. Well worth the £20 for the oil and a couple of hours of my time. Also fitted some fork protectors which will hopefully help keep the forks in good condition whilst commuting to work and back.

 

[davebike 943]

Yes  thinner oil helps  oridgnal is over damped in my view

I found most if not all Japonise bikes err on the over damped side I guess it a safer option !

[Radek 1]

My opinion is it's more important to change fork oil regularly (ie. each 2 years) than to choose "the best" oil. I used Elf 10W Moto Fork Oil SYN in the past for my Integra 750 (2014). However Matris F15K “quad valve” Hydraulic Cartridge kit F15H224K is on the way so I will probably change the oil specification based on Matris recommendation.

[Andy m 23,585]

👍

 

Oil is oil. It either meets the spec or doesn't. Yes, you can trust Castrol to meet the spec and might not trust some cut price can with Chinese labelling, but claims of added pep and zing, a nice lemony smell, unobtanium stabilised formulation etc. are just marketing guff. Buy a brand you've heard of and change it as directed in the service manual.

 

I am BTW about 2000 miles short of changing the engine oil in the Guzzi. It will going for analysis and the results will be published on the forum. I might even stick my head into the Guzzi forum where they like turning money to pollution in order to make themselves feel good about protecting their pride and joy's. 

 

Andy

[outrunner 4,457]

7 hours ago, Andy m said:

👍

 

 I might even stick my head into the Guzzi forum where they like turning money to pollution in order to make themselves feel good about protecting their pride and joy's.

 

Andy

Sounds like a fun place just like the GS forum of which I was a member for about 5 minutes when I had BMW's.

 

Andy.

[Andy m 23,585]

It's the same to different degrees with all single marque forums in my experience (This place isn't one, it's more of a single mentality forum).

 

No one can admit they bought the wrong bike or said bike has fundamental issues because to do so invalidates the purchases or every other member.

 

There is a common drive to fall back on repetitive "feel good" subjects to avoid the issues. 

 

Doing something, doing anything, is a way to avoid the elephants in the room. If you are changing the oil every 45 yards you need not worry about the stripping drive splines, grenading alternator, useless fuelling etc. 

 

Best avoid such pointless places. 

 

Over frequent changes waste money, waste resources and do the changee harm by wearing fasteners that aren't designed for frequent use, running with low oil pressure while systems prime etc. Honda, a seller of oil, is never going to under spec the change intervals.

 

Andy

[Xactly 5,436]

I have been on a lot of forums over the years. I don’t know (or care) if they’re still the same but the ones with the most obsessive members I’ve found are the RE ones, more the modern bikes than the classics, which are mostly like the other classic bike clubs.

At the time I was on these forums I had a UCE 500cc Classic. It seems that owners of these bikes changed the oil every 5 minutes when new. I have never been on other forums where a regular topic was how to repair stripped oil drain plugs. (I’d beware of buying a used UCE 500 or, even more so for some reason, a 535 CGT). BTW - where did they all go? They used to be all over the place; I haven’t seen one in years. My guess is the great scrapyard in the sky.

The other mind blowing threads were running in ones. Although a 2015 bike mine came with a first edition 2009 owners handbook (and two tins of touch up paint, a couple of spare inner tubes and a complete set of control cables). So it was bound to be rubbish because in my experience the reliability of a bike is in inverse proportion to the number of spares you get - ask any Ural or Lada owner. The handbook was written for Indian owners and mirrored that for the earlier iron barrel single. Essentially it advised not exceeding 30 mph or some ludicrously low speed for the first x hundred miles. So, we had Americans not using top gear if it meant breaking this arbitrary speed limit…. I believe the handbook needed to be Westernised to suit our roads, although the way they are deteriorating maybe we should use the low speed method…I do wonder how many big ends wore out prematurely by this nurturing. Maybe that’s where all the CGTs went? 
I imagine that things have moved on with the introduction of the Himalayan and subsequent models, though I still fancy that shares in Hitchcocks, if only they’d float the company on the stock market, would soon be a FTSE 100 company through farkle sales..

[Slowboy 20,531]

@Xactly. My thoughts exactly (see what I did there🙄) about the Enfield forums. If I read and believed any of the cobblers on there I’d never have bought my classic and missed out on a damned fine bike that I still enjoy riding after over 5000 miles.

Also agree with @Andy m. Mustn’t criticise the unicorn lest it’s rainbow trail turns to brown 😁

[Andy m 23,585]

I'd forgotten REOC. Solution to anything, change the oil three times and fit an Anal carb 😁😁😁☹😁😈😁

 

I remember similar confusion on a Triumph forum where they also endlessly recycle the name. Matey has a 790 200? Bonneville Steve McQueen Special that probably needs a good carb clean. Advice from massed 865 Bonneville SE Steve McQueen edition owners, take the battery off wait and refit before heading to the dealers 😁😁😁😁😁😁

 

Andy

Edited April 17, 2023 by Andy m