Fork Lower Spacer

Hi all.
Hoping a couple of the learned can help me out.
I have just brought a 2011 1200SE.
I tried to set the sag on the forks, but with no preload (adjustment fully out) I got 20mm static sag and rider 30mm sag. I weigh just under 100kg kitted up.

The forks have been worked with what I believe is Wilbers fork springs of unknown tension. I was given what was supposed to be the stock springs. So having forks that feel like steel rods, I decided I would go back to the stock spring until I could get the cash to get it looked at professionally.

So with a wet crappy weekend to spend in the shed I pulled them apart. This is what I found.

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The spring on the right is the Wilbers (left is stock). I really wish they stamped these things so I know what I had. The Stock spring was 295mm and the Wilbers is 262mm long. Difference 32mm.

The Wilbers spring had two washers and the following spacer. (approx 50 mm I didn't measure it)

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I assumed that this spacer and washer was the bottom spacer they show in the service manual and the parts catalog. Although it was on top of the wilbers spring not the bottom. But I assumed this was a decision by the guys who installed the Wilbers springs.  

But here is my confusion. In all the posts on the forum that showed striped down forks there is no mention of this bottom spacer. Does it exist on some models and not others?
I have reassembled the forks with the stock spring and the spacer in as the service manual showed. They are now super hard when bouncing. Sag is worse. I am now thinking i will need to pull them apart and take out the spacer.

I would love to hear from someone who can tell me if the bottom or lower spacer exists. And if so, How long is it?


cheers

I think you fucked it up ...................................

What have you done with regard to;
1. oil weight
2. oil height or amount
3. compression adjuster setting
4. rebound adjuster setting

All these things will have a huge bearing on the operation and "FEEL" of your front end.

At 100kg the stock spring/spacer/pre-load adjuster will be way too soft.

Take all the Wilbers bits with you to a suspension guru who can set your bike up properly and advise on how each adjuster impacts on the results you seek.

North side of Brisbane I recommend Scotty - Edge competition - 0431 109 675
South side of Brisbane I recommend Steve - Suspension Improvements - 3208 0082

Damping is the key to a compliant ride!

RobR,

Last weekend I was re-assembling my forks with new valves & springs. At the time I thought I should be taking pictures but with oil everywhere it wasn't going to happen. It could have been useful now.

The replacement springs were 270mm long. The instructions that came with the new springs
'Cut 50mm off the OEM preload spacer then add in the new 'stepped' collar, 10mm, and the new 70mm spacer.'

To be clear about our measurements, Jake, my suspension guy & I laid out the parts on the bench & checked that this would all add up to the space in the forks. Working from memory we ended up with a 10 or 15 mm preload.

The new spacer we mounted above the oem preload spacer.

My situation was I believe different to yours in that cos the new springs had a smaller OD there was a conical spacer to keep the spring centered. We initially installed this lower down on the spring /spacer assembly but found, because the forks became very hard to compress that the spacer was hitting the cartridge. So it was moved to above the preload spacer.

It seems you have only a spacer so there shouldn't be a binding issue.

I would take the forks apart & measure what the length of the set up was with the wilbers springs in. That is what you need to replicate, with different lengths of new spacer if needed.

If the forks were assembled with the 50mm spacer at the top, put it together like that again, try it and see.

My new springs came from Traxxion Dynamics & when talking to the sales guy he commented that 0.95 kg/mm springs were the OEM spring rate. For me at 90 Kg, with gear, he recommended a 1.05 Kg/mm spring. We will see when Spring arrives if that is too stiff.

What is the spring rate on the Wilbers? It's often engraved on the end of the spring.

Let us know what you find.

Ghezzi is right though, if you have a suspension guy available, go see him. It's an education just to see what the subtleties of the way the suspension behaves can speak volumes to a professional

Looking at the parts manual ...
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Are you saying you have #7 but not #6 with the wilbers?  Or with the Wilbers #7 and #6 are on top of the spring?  And sorry, I never measured #7 (or #6).

As for the spring rate, was the guy you bought it from about your same weight?

For the preload setting, 30mm rider sag is pretty much right.  But sounds like your thinking "these wilbers are stiffer springs for sure, fork is too stiff, let put in the stock springs with will be less stiff", that correct?

Seems like the GRiSO, for a 100kg rider, stock, has springs that are too light, and valving that is too firm.  So the fix is to put in proper springs and revalve for lighter valving.  

Problem is, you don't know if yours also got a revalve at some point.  

If you want to do this yourself, I just checked, spacer #7 is ~$6 US and is listed as an Aprilia part.  

So one cheap "make it better, maybe" option:
1. carefully look over your wilber springs, look for any makings that might help identify the spring rate. (maybe contact the previous owner??)
2. put the wilbers springs back in (if they are not way over what is right for you)
3. put the lightest wt fork oil in it you can find
4. check the service manual for fork oil height (I can't remember, somewhere like 100mm-110mm, but can't remember is that is springs in/out, anyway, manual has it)
5. set your preload for around 25mm-30mm rider sag
6. lighten your compression all the way out
7. set rebound to Dave Moss method (youtube search)

The quickest way to get it sorted is to carry it all to a suspension expert!     But that also lightens up your wallet.  

If you want to get into valving yourself, check out my thread on it ... I went a very cheap route and got great results.  
I did a self revalve (changing shims).
Nobleswood went with a kit (Racetech I think) and sounds like he'll have some feedback soon.

Thanks  for the reply's guys. I'll try and address your questions in order.

Firstly Ghezzi... yes I did. right royally.
Clearly the spacer I have was cut for the Wilbers spring so I decided to go back to the Wilbers set up.

1. Pentrite 5W (recommended for bikes that use 7.5W). I cannot be certain what oil come out.
2. I got 460ml out of them but I spilt a bit so I am putting 480ml back in. I know it is below what is recommended (520ml) but working on the "More would make it harder" theory.
3. Pretty much had Comp and rebound wound out. With virtually no compression, rebound or preload,  a trip up and down Mt Glorious would get me just over half available travel up and down the fork. (cable tie around the fork tube)

Nobleswood

I found your post very interesting. I hope I read this right in that your total length was 655mm. 270(spring) +10(collar) +  70(spacer) + 355(preload tube) -50 (cut off tube)

My Wilbers setup pic below. In order as it was pulled apart bottom left to top right.


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The measurements are as follows bottom to top.
Spring 260mm.
washer 3mm.
spacer 50mm
washer 3mm
preload tube 355mm

total 671mm

That is 16mm difference of extra preload. mmmmm.

For the record I have gone over those springs with a magnifying glass and I could find nothing etched on them. I have no idea what the rate is. I have spoken to two of the previous 3 owners and of course it was the third one that did the work. So I am really flying blind here.

Usedtobefast

I think the above post may have answered your questions. It was #7 that was causing the confusion. Neither yours or Uzidzit's posts show the spacer in any of the photos. It only exists in the parts and service manuals. The service manual pic looks like about 50mm which made me think it was OEM. But clearly not.

I'm thinking I will take the spring to a suspension guy and get them to measure it and hopefully give me the good oil, so to speak.

RobR,

You understood me correctly; basically measuring what your combined set up is & measuring what is inside the fork itself. I was wondering if with an incorrectly sized spacer you had too much preload, in effect, if that makes sense.

In re-assembling the forks I couldn't remember a lower spacer, but wasn't sure if that was just my recollection.

Because you can not be sure of how much oil is still left in the cartridge etc the best practice is to not measure how much oil goes in the fork but the air gap.

In my case the spring maker, Traxxion, recommended 7 wt oil & 125 mm air gap. Racetech who supplied the valves & shims wanted 5wt & 120mm air gap. We went with Racetech on the basis that they designed the valves for the flow characteristics of a certain weight of oil & used Showa brand 5 wt oil.

The air gap is measured before the springs & spacers go in.

Another suspicion I had was that you might have had too much oil in the forks making them harder.

I was pleased to find a suspension guy around me, so you're lucky to have two and didn't find him to be very expensive considering what I was getting from him. Mind you I was judging it against going to the doctor, or dentist or the kids braces, the upcoming cost of two kids in college /University yada yada....

My guy spent 2 hours setting up the bike for $50. Well worth it I felt.

Good luck. Tell us what you find.

Fortune favors the brave, they say ...................... but death awaits the Darwiniens.
I trusted myself altering ride heights, reducing rake & trail, wheelbase etc. These are just numbers on paper applied to mathematical equations.

I trusted the internal mods to the experts, then I played with the clickers etc.

I also couldn't find a lower spacer in my forks (stock setup) -drove me crazy looking at the parts catalog.
But it works ok for me.

I've been putting Wilbers springs in other bikes and I think I remember they've been the same size as the stock, just different windings.
Funny thing is, Wilbers hp doesn't mention fork springs for your bike...

Thanks for the info guys.  I'm at a point now where I need to get help from the professionals.
On the surface it would seem that the spacer is to long and adding to much preload. So the spring could in fact be fine for my weight. The only way I am going to know is to get it to someone who has the means to measure it.

I will also take advice on air gaps and oil weights. It's not a super hard task to get the forks off and apart but I don't really want to be doing it to many times playing with trial and error.

I have a few bikes so i'm trying to keep spending to a min. I will  look at getting the spring right so the sag is where it should be and drop the oil weight to hopefully take the harshness out of the dampening.

Looks like the spacer is none existent on the OEM setup. Maybe an older model or something.

Thanks again.

My GRiSO is a 2017, and I don't think I had a lower spacer. Not 100% sure as I was after the compression shim stack, but I don't think it just hung around at the bottom of the fork.

I took a look at a 2006 GSXR 600 parts diagram (Suzuki's version of the same Showa fork) and it does not show that lower spacer. Also, the top spacer/pre-load tube ... for the GRiSO that shows as not available (using AF1's website) but for the GSXR that tube is available for $15, just in case you need one in the future.

Also, oil height/air gap supposedly only affects the last 1/3 or so of the travel. But you can't lower it to make up for bad compression valving. So let's say your compression valving is too restrictive and does not flow enough oil with a big hit ... so you hit something big/hard, then look at the zip tie you have around the fork tube and see you did not use full travel. A person might think they need less oil in the fork ... but in this scenario it will not help, you take out some oil, go hit the same lump/hole again, and see no difference if the amount the fork traveled ... because (in this somewhat made up case) the compression valving is so restrictive and that is the issue vs. oil height/air gap.

I believe the reason for setting the oil level, or air gap, is to let the trapped air become an "air spring". Remember when early '80s bikes came with air fittings on the fork caps? If you have zero pressure at rest, you will have rapidly rising support when compressed.

On my older Jap bikes, I often overfill by as much as double to achieve a fill level of about 6 1/2" from full, with the spring removed and tube collapsed.

interesting thread guys. the dark art of suspension. I recently sent my forks off to the " experts" ( Melbourne) and had Wilburs springs fitted and " custom" damping mods . Well the springs were as soft if not worse than standard. Bottomed out even solo. The forks went back for another go. This time they tried 20w oil and a longer preload spacer ? now its feels wooden and still bottoms out. They have stopped answering my emails so I guess its going to be long road ahead. I also paid the big bucks for a custom built Wilburs rear shock. Also bottoms out - yet skittish on any kind of surface irregularity - the bike is now really hard to ride safely and I'd rather go back to soft n stock than continue to be a test pilot for so called experts whilst they try this n that meanwhile I put myself and dearest on back at risk.
tread carefully whatever decision you make and my best suggestion is to use someone very local that has direct experience with your model .

20w oil? Faarrk! You must feel like a bobble-head riding that.

Who were these twits?

guzzitragic wrote:

interesting thread guys. the dark art of suspension. I recently sent my forks off to the " experts" ( Melbourne) and had  Wilburs springs fitted and " custom" damping mods . Well the springs were as soft if not worse than standard. Bottomed out even solo. The forks went  back for another go. This time they tried 20w oil and a longer preload spacer ? now its feels wooden and still bottoms out. They have stopped answering my emails so I guess its going to be  long road ahead. I also paid the big bucks for a custom built Wilburs rear shock. Also bottoms out - yet skittish on any kind of surface irregularity - the bike is now really hard to ride safely and I'd rather go back to soft n stock than continue to be a test pilot for so called experts whilst they try this n that meanwhile I  put myself and dearest on back at risk.
tread carefully whatever decision you make and my best suggestion is to use someone very local that has direct experience with your model .

I also ordered Wilbers custom built to my weight shock. From the guys in Melbourne.
The spring was heavier than stock but still had to go up 2 spring weights to get the rider sag correct.
With the spring supplied , we had over 30mm of compression on the spring just to get the static sag adjustment.
We didn’t even try to adjust it to the rider sag.

Wilbers are the go for the BMW 9RT according to blog sites but don’t seem translate in Correct spring rate for the GRiSO.

I got my forks back from the suspension shop today. I fitted them and went for a ride. Basically as they gave them to me. (No preload and mid range dampening.) My disclaimer is I didn't have my little helper handy to take measurements to help set the sag.

Initial impression. Difference is huge. They actually feel like suspension. I need to have a play with the setting and will post my verdict.



When they pulled the forks apart this is what they found. Basically there was nothing "stock" about them.

The spring in them was unknown brand 1.0-1.4kg/mm progressive spring. The suspension guy believes it might have been out of a GSX but could not be sure.

Gold Valves. Which was a pleasant surprise.

Shim stacks listed in order by Quantity Diameter and Thickness

Compression stack
2  8.5  .15 The fist three shims allow for the .5mm recess on the valve so the first 17mm shim sit flat.
1  8.5  .1
9  17  .15
1  15  .1
1  13  .1
1  12  .15
1  11  .1
1  10  .1
1  9  .1

Rebound Stack
3  17  .15
3  17  .1
1  14  .15
1  12  .1
1  10  .2
1  9  .1

We discussed the spacer adding extra pre-load which probably would have taken a lot of the softer end of the progressive spring out of the equation but we never took it any further.

So what we took from this is that
a. the owner who had this work done was either a very big bloke,
b. was setting the bike up for the track, or
c. the person who did the work had no idea what they were doing.

So what he did.

Turns out the springs I thought were stock might not have been. They measured out at 0.95kg/mm linear which happens to right for my weight (after a good meal) and saved me $200.
Kept the valves obviously.

And lightened up the shims with the following.

Compression

2  9  .15
2  9  .1
3  17  .15
1  15  .1
1  13  .1
1  12  .15
1  11  .1
1  10  .1
1  9  .1

Rebound

5  17  .15
1  9  .2

And to top it off 520ml of 5W oil.

Like I said the first impression is a huge improvement.looking forward to doing a bit better set up and seeing what it will be like.

Good news. Sounds like you're on the right path now.

Im glad someone is getting there !
mind you I'm finding the ACCC website very informative !
Regards
Bobble head 20w Dave
not to mention the synchronised butt kicks

Hey RobR,

After riding some more what can you tell us

Hi Nobleswood.
Unfortunately the side effect of fixing up the front end highlighted the problem with the rear end. It's hard to assess the front when your kidneys are getting bashed.

The rear shock is a Wilbers (model without separate compression and rebound adjustment). It came with a 130Nm spring which is now a 110Nm and also required a reshim to make the oil flow a bit quicker. Recently found out the previous owner who set the bike up was 130kg. (I'm 95).

Now it is sorted. Ride is much better, not as harsh although the quickest i have been at the moment is 80kmph where is really seems to smooth out. Suspension is still a bit on the firm side for my weight but that is my preference and gives me a bit of fudge if I load up for touring. At the moment adjustment on both front and rear is set closer to fully open compression. But that is likely to change with more miles and a bit of fine tuning.