no variation in rebound (Shiver 45)

Klausen

New member
I have a 2006 GG 250 Marzocchi fork
my weight 85 kg without gear
my Fork specs:

130mm air
4,5N/mm spring
6mm preload
SAE 5 oil

Rebound stack:
21 x 0,1
21 x 0,1
19 x 0,1
19 x 0,1
18 x 0,1
17 x 0,1
15 x 0,1

when I open or close the rebound screw full I don't feel a difference
What is the reason?
Is the thin oil bleed to much beside the first shims.
Is a 22x0.1 Shim better - I want continue to use the SAE5 oil.

Another problem is the fork feels a little bit uptight on the first 3cm.
But the forks are parallel and the srews have right torque.
Why?
 
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It's very easy to over tighten the triple clamps, i think the spec in the manual is to tight? I made this mistake at first.

I think your have to go heavier with your shim stack with the 5w oil.
I tried 5w, but changed it straight back because I couldn't get any rebound.

1, 22x1.0
2, 21x1.0
3, 19x1.0
4, 19x1.0
5, 18x1.0
6, 17x1.0
7, 15x1.0

This is my rebound stack with 7.5w oil, I run the same spring as you.
And yes, you will need a 22x10 at the top, maybe two with the 5w oil.

I'd be interested to see where you get to with it, keep us informed please.:)
 
OK I will try the 22 Shim.

It's very easy to over tighten the triple clamps, i think the spec in the manual is to tight? I made this mistake at first.

When I maintained my fork I notice a different resistance when I push the inner tube in the outer tube.
Have anyone of you experience with "fine" honing of the outer tubes?
 
My fork has also a too soft low speed damping.

Just I read an nice article about suspension.
This sentence I found very interesting.
"Oil is such a critical suspension tuning decision that is the first priority to get worked out after spring/sag choice."

Which oil recommends Marzocchi exactly?
Because the SAE weight system has a very broad and vague viscosity range and does not even cover the viscosity range that most quality motorcycle suspension systems require.

Is there any basevalve with a parabolic shape on the market for Shiver 45?
 
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I agree with Nick, I think the 5wt oil is too light. I tried it but swapped back to 7.5wt after one ride. It felt terrible.
I have been shuffling shims in both rebound and compression stacks for the last 12 months and now have something I am happy with. I can post those if you like but mine is an '07, and I believe the size of the bleed holes in the pistons are different than the '06, and the shims you have listed are somewhat different to what I have.
Can someone can confirm there is a difference between '07 and '06 ??
 
I check the part list 2006 and 2007 there are the same compression (BE250514247) and rebound (BE250514119) pistons.

Which oil recommends Marzocchi?

How can a get more low speed damping?
 
I'm told the Marzocchi oil is about a 7w. But the closest you can get off the shelf is 7.5w.

You may have a bleed shim, if there is drop that out.
 
I check the part list 2006 and 2007 there are the same compression (BE250514247) and rebound (BE250514119) pistons.

Which oil recommends Marzocchi?

How can a get more low speed damping?

Gasgas may list the same part number, but that doesn't mean it will have the same shim stack or bleed holes drilled, they change things from year to year without much notice, or anything being recorded. Just the Spanish way I guess:rolleyes: .

Does your compression stack still look like this?

11x0.20 < I would remove this.
22x0.10 < maybe double this.
11x0.20
19x0.10
17x0.10
11x0.10
16x0.10
16x0.10
15x0.15
14x0.15
14x0.15
13x0.20
12x0.20

It looks to me that this may be quite heavy on the high speed side, you could change allot of things, but you need to decide what oil weight your going to run, and what area you want to change first.

This is the compression shim stack I run with 7.5w oil, 140mm air gap, 4.5N/mm spring with 0-1mm pre-load.

1, 22x1.0
2, 12x1.0
3, 20x1.0
4, 12x1.0
5, 17x1.0
6, 16x1.0
7, 14x1.0
8, 13x1.0
9, 12x1.0

I am 95kg kitted up, and i'm an average/fast clubman standard rider.

Hope this helps. I'm no expert in this, still learning really.
 
I'm told the Marzocchi oil is about a 7w. But the closest you can get off the shelf is 7.5w.

You may have a bleed shim, if there is drop that out.

I use Motorex. Mix in equal amounts 5wt and 10wt. When I get home from work I will post my shim stacks for you.
 
I agree with Nick, I think the 5wt oil is too light. I tried it but swapped back to 7.5wt after one ride. It felt terrible.
I have been shuffling shims in both rebound and compression stacks for the last 12 months and now have something I am happy with. I can post those if you like but mine is an '07, and I believe the size of the bleed holes in the pistons are different than the '06, and the shims you have listed are somewhat different to what I have.
Can someone can confirm there is a difference between '07 and '06 ??

i think you should post them up, remember, information is power!!!;)
 
i made a mistake i posted my mid valve stack this is my rebound stack 17x.15-19x.10-12x.10-22x.10-22x.10 sorry for the screwup
 
OK, here goes...........


’07 ZOKE

stock 1st and 2nd changes current @ 15.03.10


REBOUND/MID STACK

15 x .30 15 x .30 15 x .30
15 x .20 15 x .20 15 x .20
15 x .25 15 x .25 15 x .25
22 x .30 22 x .30 22 x .30
11 x .20 11 x .20 11 x .10*
PISTON PISTON PISTON
21 x .10 21 x .10 21 x .10
19 x .10 19 x .10 19 x .10
17 x .10 17 x .10 17 x .10
15 x .10 16 x .15* 17 x .10*
xxxxxxxx 15 x .10 16 x .15
xxxxxxxx xxxxxxxx 15 x .10




BASE STACK

stock 1st and 2nd changes current @ 15.03.10

22 x .30 22 x .30 22 x .30
PISTON PISTON PISTON
11 x .20 22 x .10 *(no bleed) 22 x .10
22 x .10 11 x .20 11 x .20
11 x .20 20 x .10 20 x .10
20 x .10 19 x .10 19 x .10
19 x .10 11 x .10 11 x .20*
11 x .10 18 x .10 18 x .10
18 x .10 17 x .10 14 x .20
17 x .10 14 x .20 12 x .20
16 x .15 12 x .20 11 x .20
14 x .20 11 x .20*
12 x .20

Each time, I have left the oil the same wt and level :
7.5wt Motorex@ 105mm = 540ml

I will try to explain what I did and why :rolleyes:
* shows a change - all I have done is move around what shims are there - I haven't bought any at all.

I bought this bike new about 15 months ago, a runout deal, so it was totally stock.
First off, the front felt mushy and blew through the stroke without any feeling. I couldn't get much improvement with the clickers. At this stage I pulled the bleed shim on the comp stack, and positioned it under the stack.
This gave a noticeable improvement but the comp clicker was all the way soft and the rebound was about 5 from full hard. The ride over roots and rocks etc was OK but there was a harsh feel when the forks were compressed - especially when riding at speed downhill and hitting a bump.
The next thing I did was take the 16x1.5 out of the comp and put it in the rebound, to try and soften the deep stroke comp and stiffen the rebound.
Now this was starting to get somewhere! I felt I was heading in the right direction!
Next I took a 17x.10 out of the comp and put that in the rebound. I also swapped the 11x.20 bleed on the midvalve with the 11x.10 pivot in the comp stack. My idea here was that I wanted soft and compliant over rocks, roots etc. but still wanted a firm enough ride on the open faster trails. I still wanted to increase "big hit rebound control" with the shims because I was discovering that too much rebound clicker would start to cause a reduction in front wheel traction when cornering etc. and multiple smallish bumps started to cause the forks to pack down and become harsh - it's a real struggle to decipher comp from rebound issues, but I'm pretty sure the lack of rebound control is the issue.
I'm still confused about that bleed shim in the midvalve - I think it is there to make sure enough oil gets past the piston and thus is available for rebound control, but...?

Anyway, now I have a setup I'm finally happy with. The current stacks as listed above are a big improvement - so much so that I think I'll leave the bloody things alone now!! The rebound clicker in particular is now very sensitive, with 1 click being noticeable - I'm about nine clicks out from full hard.
The comp clickers are around 3 - 6 out from full soft, depending on my mood!

Some other info that should be considered - It's really important to get the front and rear action to match.
The fork springs are standard, but I have fitted a 4.8 spring in the rear, the standard is 5.2. I have done this to achieve static sag of 25-30mm with race sag of 105-110mm.
This is less than is often quoted on this forum, but I find the softer rear spring absolutely brilliant. When riding, the front feels lighter than it did, and the traction up slow bumpy hills is improved, the whole bike feels more "alive".

By the way I'm quite small, about 70kg, and 167 tall.

Hope this is of some help, cheers Barry
 
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Hey, the gaps between the columns disappeared! Sorry about that! I hope you can still understand - there are 3 columns, stock, 1st/2nd change, current.
Thanks, Barry
 
I'm told the Marzocchi oil is about a 7w. But the closest you can get off the shelf is 7.5w.

Yes you told me that, but I'm told that the the SAE weight system has a very broad and vague viscosity range and does not even cover the viscosity range that most quality motorcycle suspension systems require.

look this table
PVD-ISO-Viscosity-Data.gif


Thanks for your stack , but I think the stack have only an effect to mid and high speed damping.
I need more low speed damping - I read (don't know :D ) the oil and the comp. adjuster have the greatest effect.What else?

But the influence of the cone type orifice valve in the compression assembly isn't so great.

First I will change the oil. But which kind of oil - see table.
 
I ordered Motul factory line 7,5.
With 5W oil will the fork work not pretty, I think.
my stacks

Rebound

spring
15x0,2
15x0,3
15x0,3
22x0,3
11x0,2
piston
21 x 0,1
21 x 0,1
19 x 0,1
19 x 0,1
18 x 0,1
17 x 0,1
15 x 0,1

Base

22x0,3
Piston
22 x 0,1
11 x 0,2
19 x 0,1
17 x 0,1
16 x 0,1
15 x 0,15
14 x 0,15
14 x 0,15
13 x 0,20
12 x 0,20

130mm air
6mm preload
4,5N/mm spring

It looks to me that this may be quite heavy on the high speed side,

Yes Nick the high speed dumping is to heavy I will go softer

REBOUND/MID STACK

15 x .30 15 x .30 15 x .30
15 x .20 15 x .20 15 x .20
15 x .25 15 x .25 15 x .25
22 x .30 22 x .30 22 x .30
11 x .20 11 x .20 11 x .10*
PISTON PISTON PISTON
21 x .10 21 x .10 21 x .10
19 x .10 19 x .10 19 x .10
17 x .10 17 x .10 17 x .10
15 x .10 16 x .15* 17 x .10*
xxxxxxxx 15 x .10 16 x .15
xxxxxxxx xxxxxxxx 15 x .10

Hi bchatt,

Which effect has the change 11x20 to 11x10 in the checkplate.




I also need more low speed damping.

I heard that I double up the base face shim for examble.
Do this also influence the mid/high speed damping?

I can also strenghten the checkplate.
what means this.
A harder spring or more shims?

bye
 
Hi Klausen

All looks ok to me, I think it will work fine although you wont know until you ride it, we're all looking for different things.

I think the change in bchatt's mid valve will just give slightly less bleed to it, but i think the change would be very slight.

Read this for information on mid valves, I was thinking of making changes to mine, but after reading I think I will leave it alone, as I haven't got the time to do all the testing to get it right.

http://www.gasgasrider.org/forum/showthread.php?t=4180

You could try doubling up you face shim for you low speed damping, but I think it's mostly affected but the adjuster setting, you want a nice balance between you comp stack and your comp adjuster, this is what I'm trying to achieve at the moment, as the further out your adjuster is set the less difference it makes to your damping.

Hope it helps ;) .
 
Hi Klausen
As Nick suggestes, the effect of reducing the checkplate bleed may be a bit hard to detect, but I do think forks are now riding slightly higher in their stroke, if you know what I mean. I remember thinking (the first time I rode after making these changes) that the handle bars felt higher.
The rebound stack you posted looks to me like it will be a bit stiff over the smaller or low speed bumps. I have tried for something more progressive with mine.
I think you will find that with the 7.5 wt oil you may be able to take out those "doubling up" face shims.
I also agree with Nick that we are often individual in our requirements, and the best way is to experiment in small steps and try to feel and understand what is happening each time you make a change. So, go ahead, it's easy, have fun!
Barry
 
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