Is this normal,

I have 110mm of travel when the preload is at the maximum and roughly for each mm I reduce it I loose 1mm of travel??

Hope you can tell me if this is the same with other VFR400's

Thanks

adding preload does not affect, in real terms, the travel you have.

You are compressing the spring which affects the initial rate of it.

How are you measuring it? zip tie?

When you are winding off the preload the bike is settling on the springs some more. Also remember that you need for the bike to be sat at the correct sag - approx 25mm so that the fork can extend over bumps as well as take hits from them.

Preload is your fine tuning tool when the spring rate is correct so that you can achieve the right sag.

Reducing preload will reduce compression travel, does not alter spring rate. This is how you set static sag (bike only but if dynamic sag (rider+bike) is too great then you need to increase the spring rate.

No no no. I must have not been clear. I will try again.

I see a fundamental flaw in the vfr400 forks. Well with the fork caps. The problem I see is ybT the damping rod connects to the pre load adjuster and there is a spring seat that sits below the lock nut. As you increase pre load you are compressing the spring between this seat and the top of the cartridge. But because the damping rod also is moved the same amount down this reduces the available travel. Trust me. I pulled both springs and mrasured the fork trabel available wuth zero to 17mm of preload position and at 17 mm preload i have 110mm of travel and at 0mm i have 93mm. This is bad. On modern forks the pre load adjusted compreses the spring independently of and without moving the damping rod.

Ahh...get you.

I thought the swept travel on the legs was 100mm - as surely the damping rod is not going to be the limiting fator, more the bushes for extension and the lower bump stop for compression?

Travel is determined by distance between hydraulic anti-bottoming cone and top-out collar on damper rod. Stroke of damper rod should have no effect and thus preload/damping adjuster postition should also have no effect on travel.

Yes increasing pre-load will lengthen the fork so you will have to rise them through the triple clamps to keep the geometry the same.

EDIT: the overall travel will also be affected by the amount of oil you run in your forks. This will only affect the last 20mm of travel or less (once the spring in fully compressed/bottomed out) depending how much of an air gap you run. If you have more air gap you get a little more travel as the air will compress.