Is anyone out there familiar with the anti-dive suspension units found on older gpz and zx models?
They are actuated by brake line pressure to stiffen the suspension under braking, however, one of mine is
malfuctioning causing one fork leg to be overley dampened all of the time. These units cannot be serviced and new ones are too expensive. I would like to eliminate this system altogether, but I'm a bit unsure about how to go about it. I can't figure out if these things restrict oil flow when actuated, or if they resrtict oil flow
normaly then let it flow when actuated. If the later is true, simple blockoff plates would do the trick. If the former is true, the solution could get complicated. Any advice or info. would be greatly appreciated.

 

My older zx's do not have that! Are you sure that you have stock forks?

Welcome to KF

 

Yes it has stock forks!!! All early ninjas have these anti-dive units. ZX600A1toA3, ZX900A1toA3,ZX1000A1toA2. they all use them. I've even seen them on some of the later KZ's.

 

Right on, my 7's or the 10 do not have those. So no, I am not familiar with that setup obviously. lol

 

thanks for your help.

 

Man, I know what you are talking about, but I have never tore into one. I have the b series, just after the change. I am not real sure how they work either. I would think they would use a hydraulic pressured cylinder inside the forks. But I am just guessing. I'll see if I can find some info somewhere on it for ya....

I always thought they were series'ed together, so one fork leg would not do that. But shows what I know! lol

 

What year is your bike? Is it a 600 or a 900? Mine is an '87 600R. Do you have the RX model?

 

Mines a 1990 ZX10 .....B3 series.

 

The forks don't seem to have any kind of pressure cylinder inside. It's realy weird, they aren't any different inside than any other damper rod style fork. The only difference seems to be that these things are just bolted to the fork lowers with two holes for oil flow. My original theory was that there must be some kind of baffle between the upper and lower holes, diverting oil thruogh the units, controling how much oil is allowed to return through the damper rod under fork compression. But upon inspection I found no such baffle. Now I'm baffled!

 

I see what you mean. I was looking at the schematic on bike bandit.

http://houseofmotorcycles.bikebandit...600A3%29US.asp

$133.00 for each anti-dive valve. Might be cheaper to just replace them instead of bypass them. I really don't know how it works. It is probably simple, and we are just making it harder than it seems! lol

I wonder....They sell a plunger for the anti dive valve. I am curious if the plunger is made of rubber and could possibly have a hole in it???