I'm in the process of purchasing a shock from Wilbers. Here is the conudrum.Is the shock on the GPZ 500 the same? Was there a change in the shock when the bike was upgraded in 9X?

 

S'no problem compadre. According to the Parts Diagrams on http://www.buykawasaki.com/, the part number was the same from 1989-2005 with no changes. (45014-1365.)
Just to be on the safe side, what year is your GPZ and where are you located?
-Chris in C'bad

 

My GPZ is actually a Ninja. When dealing with Wilbers, www.wilbersusa.com they speak GPZ. I've got a 2006 that I want to upgrade the shock on. We're pretty sure they have a shock with a higher spring rate 85N/mm which I figured out to be somewhere about 450 lb/in, can't find the paperwork right now though. It has the ability to have a remote hydraulic preload adjuster installed and a ride height adjuster on the bottom +/- 5mm. They also claim to be able to make a shock that will, well let me see if I can just add their stuff to this post. They have an office in NJ.

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Your personal offer:

Dear David J Evans,

Thank you for your inquiry and your interest in Wilbers-Racing-Suspension products.

So, after some confusion about the right description of your 2006 Kawasaki GPZ 500

S (respectively the Ninja 500) we are glad to finally be able to send you your personal

offer for new shock absorbers for your motorcycle!

In addition to the requested rear shock absorbers we also would like to inform you

about other Wilbers products that are available for your Kawa so that when the time

comes to think about, for example, exchanging your fork springs, you know that can

be done at Wilbers!

Please note that all the information provided are totally without any

obligations!

For your 2006 Kawasaki GZP 500 S, we can offer you the following articles:

The picture is of a 2006 Kawasaki Ninja 500

Wilbers fork springs:

As normally the standard fork springs are not chosen referring to the rider’s data,

they sometimes are too soft ex-factory and dip in too deep. At Wilbers we always

chose the spring rates, oil viscosity and also the size of the air chamber referring to

their interaction between each other and to the riders’ data. In addition, the reaction

of our springs is better than the standard, their progression is higher and they clearly

possess more reserve on the brakes. For riders of normal weight, for your motorcycle

we recommend oil of viscosity 7.5 and an air chamber of 150 mm. Below the set of

progressive fork springs we can offer for your Kawasaki is some information about

the fork oil we can recommend for your motorcycle.

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Wilbers Racing Suspension

Progressive fork springs

Order-No: 600-015-00

For US $ 99

With progressive fork springs of Wilbers-Racing-

Suspension bottoming out forks and sulky reaction

are going to be history. Due to their construction they

manage to take small road damages as easy as deep

potholes or brutal braking manoeuvres. That is the

result of our critical testing- and development

procedures. We permanently test our bikes on

racetracks like the "Nürburgring" or on the German

autobahn. This provides us with the necessary

experience of creating the ideal progressive fork

spring.

If you want to exchange your fork springs, we always recommend an exchange of the

fork oil as well so that the ideal interaction between spring, air chamber and fork oil

can be achieved. During the installation, one litre of fork oil will be sufficient. For the

ideal interaction, we suggest the following fork oil:

Wilbers Racing Suspension

Wilbers fork oil viscosity 7.5 SAE

Article-number: 610-075-00

For US $ 14.90 per litre

The right choice of oil

The importance of the right choice of fork oil is often

underestimated. As for Wilbers-Racing-Suspension forks,

the ideal oil is delivered by the same provider. Our fork oil

leaves no open questions concerning its damping abilities,

gliding characteristics, constancy and sensitivity. Wilbers

fork oil provides a loss of wear and is available in seven

different SAE-classes. The higher the SAE-class, the

thicker the oil will be. Thus, the viscosity of the fork oil is

another way of influencing damping quality. A low-viscosity

oil (SAE 5 or 7.5) will reduce damping.

A high-viscosity oil (SAE 15 or 20) will increase damping.

So, always use Wilbers oil!

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Wilbers Racing suspension shock absorbers:

All our Wilbers-Racing-Suspension shock absorbers are available either in the

Sports-line, which is equipped with a blue spring, or in the Classic-line which is fitted

with a black spring and overall more classical in its looks.

They only vary in appearance and not in performance, flexibility or price.

We also would like to inform you about one of Wilbers specialities … At Wilbers you

have the possibility to raise and lower your motorcycles’ ride height by lengthening

and shortening our Wilbers shock absorbers. This way, even very large and very

small motorcyclists gain better control over their vehicles.

Those special

constructions at Wilbers are without extra charge!

For example, depending on your choice of the shock absorber, we would be able to

lower the seating height of your Kawasaki for as much as 50 mm (approx. 2.0

inches). Of course, less is also possible!

This; however is only advisable if your bike really is too big for you! If you are

satisfied with your seating height you should not think about lowering because you

would lose lean-angle capacity as well as handling!

For your rear suspension, you might decide between three different shock absorbers,

one is form our Wilbers Racing-Suspension line and the other two belong to our well

priced Eco-Line!

Please note that only with the Wilbers-Racing-Suspension line

shock it will be possible to mount the requested accessories, the hydraulic

preload adjuster and the ride height adjustment tool!!!

So, please take a look at the recommended shock:

Wilbers Racing Suspension

Type 630 Road

Ø 36 mm

Article-number: 630-197-00

For US $ 449

[font=verdana][size=1][left]Racing-Su

 

Sorry I couldn't post the pictures

To convert N/mm to lb/in I used this, see below, and came up with 485 lb/in
To Convert lbf/in to N/mm (Pounds-force per inch to Newtons per millimetre)

lbf/in x 0.175 = N/mm, Example: 100 lbf/in x 0.175 = 17.5 N/mm
To Convert N/mm to lbf/in
N/mm x 5.714 = lbf/in
OR
N/cm x 0.5714 = lbf/in

When I tried to go backwards with this though to look at my front fork spring rates it didn't make much sense. I'll have to look into it some more.