Another Fork Question

[evil_henchman]

The manual gives a spec but what oil brand and weight do all you suspension gurus use in your forks? Thanks!

 

[snikr]

The manual gives a spec but what oil brand and weight do all you suspension gurus use in your forks? Thanks!

I used Sikolene 7.5 WT oil when I put in my Wilbers front springs. I've also heard that Belray is good oil. Not sure about Yamaha fork oil.. Hope this helps.

Tom

 

[dobias]

evil,

You've just opened Pandora's box. If you use search you'll find this subject has been talked to death before.

IMHO you need to avoid SAE labels and look for the CentiStokes reading at 40 degrees Celsius (cSt@40C)

The second reading of cSt@100C is when the oil is hot. Unless you're a dirtbike rider ignore this reading.

https://www.peterverdonedesigns.com/lowspeed.htm

has a very good explanation of fork oil viscosity.

The factory fork oil is Yamaha #01 that is SAE labelled as 10w but is virtually the same viscosity as Silkolene's SAE label of 2 1/2w. That is the oil I selected after trying out Silkolene's 10w fork oil & finding it too stiff to have a full range of fork adjustments.

dobias :glare:

 

[Rogue]

I used Motul 7.5w synthetic when I put my Wilburs springs in.

 

[Bounce]

I used Sikolene 7.5 WT oil when I put in my Wilbers front springs.

+1

 

[Geezer]

I used the Silkolene 2.5 with the Wilbers springs. Works very well for me.

 

[afterburn]

I use Liqui Moly 15W, perfect for me.

 

[Toecutter]

I use Silkolene 10W myself, recommended by Gary Mc Coy for two-up riding.

 

[dobias]

By the way,

the original recommendation for "7 1/2w" fork oil was by Wilbers and assumed the use of their fork oil.

There is no record of the centistokes measurement for their oil. I asked Wilbers, himself, through a German fluent friend. I repeat Wilber's advice: "Try Wilbers fork oil and you will be happy".

Using another brand of 7 1/2w fork oil is just plain guessing as to matching the viscosity of Wilber's oil.

Your guess is as good as anyone's.

I prefer to use the definate viscosity recommended by the fork manufacturer, not a vague recommendation by a one-size-fits-all fork spring provider.

YMMV, etc.

dobias :glare:

 

[twowheelnut]

I used Motul 7.5w synthetic when I put my Wilburs springs in.

+1

 

[f1fan]

I don't want to hijack the thread for my question, but it is somewhat related and I didn't want to start another oil related thread.

Earlier in the thread dobias mentioned a website that compared the weight and the viscosity of different fork oils. After reading the article on that website I have to agree that the data makes a lot of sense and that you can not just go by the labeled weight that's on the bottle. Silkolene Pro RSF 10W does not compare to the Yamalube 10W at all, in terms of viscosity at temp. The Silkolene Pro RSF 2.5W comes actually closer to the OEM Yamalube. Interesting to say the least and not what I would have thought.

Now my question. Is there no other way to change the fork oil other than to take the whole fork leg out and turn it upside down to drain the old oil? Other bikes I've seen have fork oil drain holes. The FJR apparently doesn't, or I haven't discovered it yet.

Ingo

 

[dobias]

Ingo,

The consenus of opinion is that the forks should be removed to clean them properly. I gather that the adjustments at the bottom of the forks are removeable and allow drainage. While I don't yet have any experience doing that,and can't recommend it, I may try it the next time I change fork oil.

dobias :glare:

 

[ionbeam]

+1 with dobias

The oil can be drained by removing the damper rod bolt after the front wheel has been removed. There are at least 3 problems with this:

1. You can't really do a good flush; my forks really needed to be flushed. In fact, the first time I flushed them it didn't get the job done. I had to rinse them with kerosene, drain them over night then flush again.

2. You can't set the oil height. Wilbers and the FSM both said my oil level should be 100mm. Both my forks measured ~114mm before the flush so I couldn't use level I found for refill reference.

3. It will be very hard to purge air out of the tubes after draining. It is pretty much necessary to be able to collapse the fork tubes and leave them vertical to do the job right.

In the end, it turns out not to be such a hard job to remove the forks. Perhaps there is some first time task intimidation but after that it should be pretty simple.

 

[Groo]

+1 on Ionbeam's comments. Once you just get started, the job is easier than it might initially look. It's the getting started part for me that is always the hassle.

 

[radman]

Fleet Farm 75-90w. Talk about damping..................

 

[f1fan]

Thanks for the comments guys.

I see now that there is no other way that would get the job done properly. Ionbeam is right, it's the first time intimidation that's getting me.

But, I need to do it. It's an '04 and I have never changed it. I am fearing the old oil to be pretty nasty.

 

[ionbeam]

Check out Warchild's FJRTech site for a how-to on flushing and changing the fork oil. The procedure says, "the two side fairing pieces, the two front-end black inner panels, and horns" need to come off but I didn't find it necessary though it would give better access.

At the Micapeak site there is another how-to with pictures, click here. This page actually details how to fix a wimpy '03 front fork but the basic procedure to access and close up the forks remains the same. This web page will be more useful just to preview the parts you will be getting into.

Ya do have da FSM, right? (shop manual)

 

[Shadowfax]

I also used Sikolene 7.5 WT oil when I put in my Wilbers front springs but found the result to be "too plush" or maybe "too slow" and will be changing to a lighter Sikolene at the next fork service.

 

[Groo]

To add to Ionbeam's latest comment... I found I needed to take my Magnum Blaster horns off the attaching screws to get enough wrench room, and found at the same time that there were lot of little pieces of gravel inside them.... got them out by swirling the horns in a circular motion... just something odd i found when doing it... must have kicked up off the road as I was riding....