Elementary questions

[jossbuk]

Sorry everybody but I am trying to keep up but there are some terminology that I can not fathom.

1) Somebody on this forun mentioned that the KTM 2002 front fork standard shim float was 1.5mm. Somebody please explain what that means. (UK english ha ha)

2) Mid valve float. What is that.

one more

3) Increase midvalve float/decrease midvalve stiffness. What would be the affect and what would you alter in the shim stack.

OK last one

4) Why do some forks have 4 0.1mm shims for a check valve when there is a spring behind them anyway? I can quess but would like to know properly.

I am OK on crossover shims. HIGH speed and LOW speed areas etc. (I think)

Look forward to your replies

Joss

 

[JTT]

I'll give it a try in Cnd english anyways :)
Float is simply the amount that the shims lift off the seat of the valve before beginning to bend (and meter fluid).
If you increased float you are effectively bringing the midvalve metering into effect at a later stage. Decreasing the stiffness will make it softer.
I am assuming you are referring to the midvalve with the spring? The spring simply allows the ports in the piston to be shut off when the fork is in rebound mode forcing fluid to pass by the rebound shims instead of "sneaking out" the compression ports.

Help any?

 

[jossbuk]

Thanks for your help JTT. This is now running on the same topic as my other thread so I only have one more question.

I realy need to make a sketch of the internals of the WP fork so that I can visualize what is happening as the forks go up and down(Has anyone done One?). I presume that the compression stack must open at the same time as the mid-valve. One can't open without the other. Is that right. If this is so, where would the 1.5 float and 4 off 0.1 shims in the midvale come into play? As I have said before I can visualize the workings of the compression stack... I am happy with that. Look forward to your replies

Joss

 

[Daveyyz250]

Joss, I don't know if this will help any. Ohlins have a web site displaying the function of their damper systems. If you link onto www.ohlins.com and follow the drop down index to motorcycle. There is a section you may find interesting. All the best, Dave

 

[jossbuk]

Thanks Dave, It helps

 

[JTT]

Joss, the base valve opens from the fluid displaced by the damper rod as the fork is compressed. THis is important to keep in mind, as many think that it is fluid pushed through by the piston, when in fact the piston has little to do with it. The base valve could theoretically operate without the piston even being there. The midvalve provides supplementary damping.