Fork Oil

I did some looking around and in the manual I have it says nothing more than "Fork Fluid"

Do any of you guys know what weight came stock in these forks? Im going to change mine this summer and was thinking of going to somthing a little heavier.

bakeray wrote:I did some looking around and in the manual I have it says nothing more than "Fork Fluid"

Do any of you guys know what weight came stock in these forks? Im going to change mine this summer and was thinking of going to somthing a little heavier.

Whale snot was the best description that I have heard for what came out of my forks when I change the original oil and I think that the only thicker stuff would be road tar .
My problem has been the opposite to yours that the damping on my forks is far too firm for the single track trail riding I am doing .

There is a wealth of knowledge here and well worth reading. I skimmed through it some months ago and have returned to it now to find the answers to all my questions . I suspect that yours has been modified at some point.
http://borynack.com/XR650R/xr650r_forks.htm
I am about to strip my forks down and drill out the valve as recommended in the article. I have a 7 weight oil in and both pre load and compression adjusted to fully out.

Just made a tool to set the fork oil heights correctly, need to get soem fork oil next question is just standard fork oil from local dealer or anything special ?.
Also manual says 637mm cubed or oil...is this per leg or total ?, I know the depth is 120mm from top of the fork leg but don't want to strip her down and only have enough oil for 1 leg.
Anyone know the answers .

Looking at the link above they state 2.5wt or 3wt is that the viscosity rating ?.

637ml per tube. so you need over a litre

2.5 weight oil is as runny as water and not a common oil in general bike shops.

http://www.putoline.com/en/products/catalogue/segp_scooter/psusp/466/scooter/suspension-oils/hpx-25/

Hew wrote:637ml per tube. so you need over a litre

2.5 weight oil is as runny as water and not a common oil in general bike shops.

http://www.putoline.com/en/products/catalogue/segp_scooter/psusp/466/scooter/suspension-oils/hpx-25/

So shall I go with the 3wt or the 2.5wt ?.

H & M,

that link - I didn't check but I'm sure it does - links to Borynack's setup of the std forks.
Hearsay has it that this is, by the majority, regarded as absolutely superb, and it's also the reason why I'll do it (got springs coming). And, most important, you indeed fill up with 2.5 SAE oil, quite like you say "unusual" and " not very common" - oh, and thin it is.
...Off topic: read yourselves about B's shock-setup, as the opinions about that bit is a mixed bag!!!...
The latter, relative scarceness, is the reason this oil is already waiting in my cupboard, as I saw it on a rack somewhere. SAE 5, 10 & 15 are really common, and I've mixed them before, they work well but for our forks 2.5 is recommended.
That, however, is for this 'modified' fork, with even the drilled-out rebound (I think I remember this bit) hole.

Same hearsay has it (I've read an awful lot, U2 I hope) that also the whale-snot is to be replaced, for standard forks, with this thin stuff, same viscosity, same thin-ness, excuse the rape of English here. Hey, fill up with SAE 30 if you like, but do report then what you find about the results
I'll stick to what others already have found out, call me lazy?
Cheers Mates!

Edit: come now Mauser, 2.5 & 3 is splitting hairs here. If you can find 3 but not 2.5 then do a Nike, "just Do It" Oh, 1 thing is important: buy a synth eh, these low viscosities you really want in a synth, much much more stable time-wise. Besides, I doubt if minerals go this thin. Motul makes it........ yeah, I know it's French, but geeeezzz, get over that bit

Cheers Burp, just did want to strip the forks down and stick the wrong stuff in.....as follows.
Mauser "hi guys just re-filled my forks with 2.wt oil"
Burp "Nooo Mauser you noob everyone knows you need 3wt"
Mauser "Now you tell me"

Maus,

you & me would be hard pushed to notice a difference when pouring (at normal temperatures!) SAE 2 and SAE 4 next to each other. Also an engine will have trouble to see a diff, as their bearings work on hydrostatic principles once they spin.
A shimstack like in a fork/shock though works on totally different principles, as this relies largely on the internal friction properties of the oil itself. It will definitely 'see' small differences, and I'm sure Rossi's technicians will not even think of using a 'close-enough' viscosity when they are changing the oils.

But, and it pains me to say this here in public, I am not Rossi. And you're not either because then you'd not ask here but tell your crew to do good, basta! I think that filling up with SAE 5 will make a difference, it's double the weight-rating, and not what B designed his documented setup for.
I'm sure that such would have been possible though, with a quite different shimstack, valving etc, but he didn't. Keep in mind that thicker oil heats up more too, simply because there's more friction generated, and using thinner oil will reduce this, which means a more constant temperature - and that means a more constant damping because the oil won't thin as much.

Pls tell us here what you will do & what your findings are, the diff's between before & after? I for one want to know, I've got the B-mod ahead of me, including the drilling-bigger of the valve-hole, and would like to hear what others, also when they do different, find.

Once I get the oil I will do a load of pictures of the strip down, only going as far as changing the oil so won't be removing the cartridge seals etc.
Going back to the oil reading the forums a lot of people use 5wt which is probably what I will go with.
My front end just doesn't seem right....won't soak up any bumps and the fork gattor rolls over @ the top even on smallish bumps, I am guessing the fork oil is knackered...been in there since 2002

I understand BWB63 using Golden Spectro Ultra light 2.5wt in the forks,
but for the rear shock do you use; Race Tech Ultra Slick Suspension fluid
ThumperTalk - Re: Fluid for modified XRR rear shock? 2/19/09 3:56 PM
http://www.thumpertalk.com/forum/private.php?do=showpm&pmid=1836541 Page 2 of 2
US-0 or US-1 or even Maxima Light 75-390 for the modified XRR rear
shock; or stay with Golden Spectro Ultra light 2.5wt for the rear shock?
Thx,
Bob


5. What suspension oil do you recommend?
Racetech US-0, Golden Spectro Ultra Light suspension fluid, Maxima Light
3wt 75/395 are the best to use. At $25, $15 and $10 a quart
respectfully. So, if money is an issue use the Maxima. It is important to
use fluid with 2.5~3wt in the suspension setups on the web site. The
shim stacks are setup for it. If you do us 5wt if will still work great but,
your adjustment will be different and the suspension will feel more
muddy and slower to respond. I have used RaceTech's US1 and love
it....$25 a quart is not fun
Get the viscosity index of the fluid. Something like 75/395 is the best.



The Golden Spectro 2.5wt and Race Tech Ultra Slick US-0 are real close to the
same with Race Tech Ultra Slick US-0 being better in "feel" and how long it holds
that "feel" Race Tech Ultra Slick US-1 and Maxima Light 75-390 are close but,
the Maxima Light 75-390 is a little lighter but, the Race Tech Ultra Slick US-1 is
a better fluid. Money, and if you want to slow down the suspension just a tad is
the difference. Golden Spectro 2.5wt and Race Tech Ultra Slick US-0 are a little
light at times for the forks but, I way prefer those for the shock, if money is not
an issue Race Tech Ultra Slick US-0 all the way and you may need to pump up
the slow stack all around for a serious race bike. For most it is splitting airs for
these four fluids and most would never tell the difference so, for most it is
money and Maxima Light 75-390 is the ticket. I use this in the forks alot to slow
down how bussy they get in the chatter. Think of them as four flavors
Are you still going to have me do the suspension or have you moved on to
something else?

Mauser,

seems you still have the so-called whalesnot in there (mine too, but a new 2007 model)! Hearsay has it that anything new in there - beer, catpiss, water or why - will be an improvement, so also 5W.... so this may be why some report "good" with 5W, quite likely actually.
But you're only going to change the oil, no mods, so that's a quicky sortof - fill with 2.5W first? No fortune by any means, and my guess is you'll like it - but if not chuck it and fill with 5W, or mix your own viscosity (say 50/50 2.5&5W for a 3.75W).
You've heard that some forks have rust in them with the std oil? When you get in there better check for this! If you've got it you'll need to take it apart fully, and clean with a microscope, and then you may well consider doing that mod maybe??
Cheers!

BuRP wrote:Mauser,

seems you still have the so-called whalesnot in there (mine too, but a new 2007 model)! Hearsay has it that anything new in there - beer, catpiss, water or why - will be an improvement, so also 5W.... so this may be why some report "good" with 5W, quite likely actually.
But you're only going to change the oil, no mods, so that's a quicky sortof - fill with 2.5W first? No fortune by any means, and my guess is you'll like it - but if not chuck it and fill with 5W, or mix your own viscosity (say 50/50 2.5&5W for a 3.75W).
You've heard that some forks have rust in them with the std oil? When you get in there better check for this! If you've got it you'll need to take it apart fully, and clean with a microscope, and then you may well consider doing that mod maybe??
Cheers!

Yeah spot on Burp, only wanting to pull apart and clean and fill with fresh fluid, probably be 5w as anything will be better than whats in there....snot or nowt lol.
Just waiting for the right stuff to pop up on ebay then I will buy it and do the job, not desperate hurry more a project, coolant changed. Getting a new clutch perch soon so will change brake fluid as well....DOT4 so no big choice nothing wrong with mine but friends going to send me 1 with the brake switch complete and a new stock hose...not bothered about going braided I don't do any heavy braking, I only go max 50mph on the tarmac.

If I need to go faster I climb on the ZX12R
https://www.youtube.com/watch?v=VbdF3BzOPwA&feature=related

Ordered the oil today went for this stuff, should be here within the next day or so...time to start pulling the wheel and seeing what's what .

Silkolene Pro RSF 5wt Racing Fork Oil
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=370452106033&ssPageName=STRK:MEWNX:IT

Little update pulled both forks and have drained them down and flushed 99% of the muck out of them.
Some local rust on the inner tube...as mentioned a common finding.
I have taken some pictures but cannot be bothered to upload tonight.
Small question stock springs free length are supposed to be 506 mine are 509 & 510 long without the spring guide washer, strange how they are slightly longer than stock....service life is 496.
Any thoughts guys ?.

Yeah I do: they're too long so you're too light!
You don't eat enough Mauser, so do the right thing, start looking at yourself: go frequent McDonalds, Kentucky Fried Chicken, slurp some carbohydrate-shakes and fill yerself to the brim with greasy matter. Oodles of mushy peas perhaps? Well, anything rich, this instead of burning cals as a result of tiring riding!
LOL
No idea why yours measure longer, but I'd regard such as 'good', the forks can't have been abused too much I'd say. That is, if they're the standard springs???? Find out by setting the sag, or at least measuring them? At the very least you'll find out if you've got the roundabout correct springs in them.
Dunno (yet, have to mount my new springs still) about the setting/adjusting of the pre-tension but I know sometimes bushes (cut to required length, spacers) are used.

hi fellas,i did this mod(drilling the valve and re-filling with 2.5wt oil)after being advised by hew on another forum.at least i believe it was hew.the forks are much more supple than stock and make life a little easier at the sort of trail speeds i travel at.mostly technical stuff and the odd moor.







last pic shows the difference in hole diameter,still have to drill the hole at two o'clock.worth doing if you have to replace an oil seal and the forks have to come apart.my right seal started leaking two rides after the mod and had to be stripped again.

great site,glad to be aboard.

Nice One

I have found front tyre pressure to play a part as well.
Soft pressure -- 10PSI is good in mud/ soft going
Hard pressure --- 15 PSI is better on dry rock.

Ponty,

why did you drill all 4 holes? I remember that only 2 (opposite) holes were to be drilled, I seem to remember that they were for the compression damping only or something like that.
Pls tell, and welcome aboard indeed.

BuRP wrote:Ponty,

why did you drill all 4 holes? I remember that only 2 (opposite) holes were to be drilled, I seem to remember that they were for the compression damping only or something like that.
Pls tell, and welcome aboard indeed.

All 4 holes need to be drilled. The photo in the instruction page shows two drilled and 2 standard just to show the difference in size.
Suspension tuning on other makes is a real secret. Its a great resource to have

http://xr650r.borynack.com/

BuRP wrote:Ponty,

why did you drill all 4 holes? I remember that only 2 (opposite) holes were to be drilled, I seem to remember that they were for the compression damping only or something like that.
Pls tell, and welcome aboard indeed.

thank you.