Rebuilding a stock front end on a KZ900

Gents,

My fork seals are leaking so it's time for a rebuild. I've been eyeing Race Tech's cartridge emulator kit for quite some time now, I suppose it's time to bite the bullet and install one.

My question is what springs to use and should I use a preload spacer?

I'm leaning towards Race Tech's springs , because they're the same manufacturer of the emulator kit; but I also know Progressive makes some pretty nice springs which would match my Progressive Series-12 rear shocks nicely.

Any thoughts?

Go with the springs recommended by Race Tech.

Those Gold Valve emulators will transform your forks.

i found the progresive spings to be a waste. once u add the spacers u colaps the soft part of the spring.
get everything from raceteck. ask them what springs they recomend, before u buy anything. they may or maynot recomend a progressive type spring?

I'd stick with straight rate springs and tune the forks accordingly. I'm going with a stiffer spring when I install the emulators.

Thanks guys!

mark1122 wrote: i found the progresive spings to be a waste. once u add the spacers u colaps the soft part of the spring.
get everything from raceteck. ask them what springs they recomend, before u buy anything. they may or maynot recomend a progressive type spring?

Good point! Will share what they have to say.

Kidkawie wrote: I'd stick with straight rate springs and tune the forks accordingly. I'm going with a stiffer spring when I install the emulators.

Yeah, I'm going with a stiffer spring as I weight more than average.

I will inquire about this, but their spring rate calculator is a bit funky.

When I pick my bike, a Z1/KZ900, I only have the option to input my weight as a rider and their spring rate calculator says I should go with a 0.951 kg/mm, so I can choose between .90 kg and the 1.0 kg springs. However, when I pick a 77-80 KZ1000, I have 2 more options, riding type (street or race), the semi-wet bike weight (I'm using 525 pounds), as well as the rider weight. With my inputs entered correctly (my weight is 230 pounds), the suggested spring rate is 1.1 kg/mm and the stoutest spring rate they sell is 1.0 kg/mm so it looks like that'll be my best bet. I'll confirm with them.

Thanks again!

Talked to Race Tech, they recommend the 1.0 kg/mm springs paired with the 15 wt fork oil. Bada bing, bada boom

You will also need to set-up the preload to give the correct static sag. I have mine set to 35mm front and rear. Doing ths will give you the best stability, ground clearance and agilty.

893cv wrote: You will also need to set-up the preload to give the correct static sag. I have mine set to 35mm front and rear. Doing ths will give you the best stability, ground clearance and agilty.

X2
then u measure your max fork compression during braking (by using zip ties)and adjust accordingly. u want to use all but the last 10 t0 15mm of travel under max breaking.

For sure! I got Race Tech's Suspension Bible and will get some reading done before I start any work.

893cv wrote: You will also need to set-up the preload to give the correct static sag. I have mine set to 35mm front and rear. Doing ths will give you the best stability, ground clearance and agilty.

What bike and what rear suspension? I don't think my Z1 rear suspension compresses 12mm under it's own weight (static).