Z4 Is it true??

[Gallain]

I heard that the Bomber Z4 -01 gets harder the faster it goes.
Is it true??


Thanks for all of your replies, I now know it’s because of lack of HSSV (High Speed Sensitive Valve) that the fork can feel harder during rides in high speed.

[FlipSide]

My guess is that it is true.

The damping force is proportionnal to the velocity (F=-Cv) which means that the faster the wheel moves upward, the stronger is the generated damping force that counteract this movement.

This should apply to forks that doesn't have a speed-sensitive damping (just like your Z4 I believe).

I know more about physics than about suspension technology, so please somebody correct me if I said something wrong. Thanks!

[Gallain]

It makes sense to me. I had forgot why it was supposed to get harder. But now you reminded me thanx!!!
:D

[Yossarian]

i think you are referring to a progressive spring rate, which your fork probably has. you can probably get a more linearly spring rated fork.

[FlipSide]

Originally posted by Yossarian
i think you are referring to a progressive spring rate, which your fork probably has. you can probably get a more linearly spring rated fork.

Oh yeah that's possible! The Z4 is an air fork right?

The question should have been: "the fork gets harder to compress as it progresses through the travel". If the Z4 is an air fork...then this is also true.

[Gallain]

No it's not air... It's the coil version i'm speaking about.

The faster the bike goes... the harder it gets.

[Yossarian]

Originally posted by Gallain
No it's not air... It's the coil version i'm speaking about.

The faster the bike goes... the harder it gets.

The harder what gets?

[Gallain]

Originally posted by Yossarian


The harder what gets?



The dampening in the fork...

[Yossarian]

Originally posted by Gallain




The dampening in the fork...

:confused: :confused: :confused:

do you mean the compression rate of the fork, or the speed of rebound after compression?

And what do you mean by speed/faster. the faster the bike is moving or the faster the fork is compressing & rebounding?

[Gallain]

Originally posted by Gallain
I heard that the Bomber Z4 -01 gets harder the faster it goes.
Is it true??


QUOTE]Originally posted by Gallain
The faster the bike goes... [/QUOTE]


Originally posted by Yossarian


:confused: :confused: :confused:

do you mean the compression rate of the fork, or the speed of rebound after compression?

And what do you mean by speed/faster. the faster the bike is moving or the faster the fork is compressing & rebounding?



The velocity of the bike.

If you read the at the top you will notice that I was wondering. Since all I heard was that that the faster a bike equipped with a Z4 travels the harder the fork feels. And I was wondering why, or if this statement was true. One person said that if you go fast enough the fork will feel like a rigid one.

Sorry but this is all I know.
But I have now got the answer in the first reply. The Z4 doesn’t have speed sensitive dampening.

[The Toninator]

I heard that the Bomber Z4 -01 gets harder the faster it goes.
Is it true??...
...And I was wondering why, or if this statement was true. One person said that if you go fast enough the fork will feel like a rigid one.
I'm going to say that's a false statement. It wouldnt be a suspension fork if it did kind of counterproductive. but then again i'm just saying....

[1speed]

ask the all knowing Angry Asian
http://www.angryasian.com/cgi-bin/Ultimate.cgi

[ChrisRobin]

If I understand what everyone's saying...the Z4 starts to feel for rigid in it's travel as you go faster. Well now, I guess I won't be getting a Z4 I was looking at for my little hard tail. Thanks for the heads up!

[Gallain]

I tried it as I went home from work this morning. The fork is very nice and plush until you reach above 35-40 Km/h. Then it wasn’t as plush any more but it didn’t feel rigid at all just a bit stiffer.

So much for listening to rumours… It’s much better to go out and try for yourself.

[schaefdog]

umm. SSV is to deal with the speed of the compression, not the speed of the bike. so no, that is a false statement. thi SSV is meant to slow down rebound and compression on big hits, and avoid bottoming. i probly said that all wrong cuz im tired, but it has nothing to do with the speed that the bike is going, cuz the bigger forks have SSV to, like the Jr. T, Super T, and the monster T. this year the monster and super have HSCV (high speed compression valving) which is just a refined version of the SSV (speed sensitive valving)

[Gallain]

They explained it to me that the Z4 valves didn’t have some holes in them.
So when the oil started to run through faster and harder. (which is what happens when you go at a higher speed)
Not enough oil can pass trough the valves thus making the fork stiffer...

Am I wrong?

[Brian Peterson]

Originally posted by Gallain
They explained it to me that the Z4 valves didn’t have some holes in them.
So when the oil started to run through faster and harder. (which is what happens when you go at a higher speed)
Not enough oil can pass trough the valves thus making the fork stiffer...

Am I wrong?

You pretty much have the right idea now.... There are holes in the pumping rod on your fork. As you said, the oil can only flow through it so fast. When the fork trys to compress faster than the oil can flow through the holes, the fork resists compression. This would be an increase in the compression damping, or the stiffening that some have mentioned. These simple physics allow the fork to be plush for smaller bumps without completely blowing through the travel. But note spring rate, oil height and oil weight are also contributing factors in how a fork rides.

Brian Peterson
Marzocchi USA

[Gutty]

What Gallian and BP (of course)said is true. This is generally known as spiking. I have a 00 Jr.T QR20 and at speed it is not the best. But i generally think the Jr is good value and makes quite a good hucker. Just don't try to race on it.

[way2jedi4u]

yeah its true..i tested....now wanna buy my z4?