Any experience with Race Tech?

Good thread. As it happens I have been looking into this as well for my Z1000A1 rebuild.
Davel: with the valve on top of the rod, how do you fasten the bolt on the bottom? Usually you need a special tool (I use some long piece of threaded steel with a 17mm bolt fixed to the end) to keep the rod from turning while fastening the bottom bolt. That wouldn't work here as far as I can see.
Dutchz: how much of an improvement are the 38mm versus the 36mm forks?

Zthou1977 wrote:

with the valve on top of the rod, how do you fasten the bolt on the bottom?

The gold valve just sits on top of the damper rod and is held in place with the fork spring. So, after the damper rod is installed, you drop the gold valve in, make sure it's sitting on the damper rod properly and install the spring.

You can remove the valve with the forks assembled. Just remove the spring, reach down the fork tube with a parts grabber and pull it out. This is necessary if you need to tune the valve.

Instructions attached
Note: these instructions say "Harley Showa 41mm". The KZ1000ST has 40mm fork tubes and use this model gold valve.

instructions part 2

Boy, i just looked them up and I think i am convinced. $170 is a lot of bucks but might be worth it to get rid of all this dive I have on the bike. You don't get much for the $170 but I guess it's worth it.

otakar wrote:

You don't get much for the $170 but I guess it's worth it.

Definitely worth it! The quality, results and service are all A+. This guy's been around a long time, knows his stuff and is very helpful.

Matthew Wiley
Race Tech Inc.
1501 Pomona Road
Corona, CA 92880
951-279-6655 ext# 108
951-279-7171 fax
mwiley@racetech.com
www.racetech.com

This from Kevin Cameron's Sportbike Performance Handbook. Gold Valves use the Spring Backed Rigid Washer system.

Kevin refers to fixed orifice forks as having "all the sophistication of a screen door closer"

otakar wrote:

$170 is a lot of bucks but might be worth it to get rid of all this dive I have on the bike.

If you're experiencing a lot of dive, pay close attention to and experiment with fork oil level. Changing the oil level effectively changes the amount of air at the top of the fork. Under heavy load (braking), this compressed air assists the spring to support the front of the bike.

More oil = less air = higher air pressure = more support = less dive.

I can do that anyway since I have air caps on mine. I have also installed helper springs on top of the stock fork springs.

not to beat a dead horse here guys but ive had good luck just running 30w synthetic motor oil to help take some of the dive out of stock frontends in place of that 10w crap,being the basically cheap bastard i am ive had no problems with it soaking up bumps and doesnt dive nearly as much when hitting the skids hard seems to help keep rear tire on road better when braking

Zthou1977 wrote:

Dutchz: how much of an improvement are the 38mm versus the 36mm forks?

I have not ridden the bike with the new front end yet, I'm in the middle of a rebuild. They should be a bit stiffer.

davel wrote:

otakar wrote:

$170 is a lot of bucks but might be worth it to get rid of all this dive I have on the bike.

If you're experiencing a lot of dive, pay close attention to and experiment with fork oil level. Changing the oil level effectively changes the amount of air at the top of the fork. Under heavy load (braking), this compressed air assists the spring to support the front of the bike.

More oil = less air = higher air pressure = more support = less dive.

True, and on top of that you can run stiffer springs because of the increased oil flow and better damping. The stock KZ springs are really soft. You can either buy a stiffer spring from Race Tech or cut down your stock springs to increase the spring rate (which you can compensate for with a spacer). The more coils you remove the higher the spring rate.

If you, like me, do not have a spring rate measuring device, there are online calculators that will help you approximate the stock spring rate. You need to measure wire diameter, spring OD and count the number of active coils. Punch in the numbers and the calculator will give you the spring rate.

Here's one of many online calculators:
www.proshocks.com/calcs/coilsprate.htm

You can then reduce the number of active coils to obtain the desired spring rate. Race tech has a calculator on their site that gives a spring rate recommendation. Mine was 0.95 lb/in.

The springs in the 38mm police front end turned out to be stiffer than the springs in my old 36mm front end - I assume because the police bikes were a lot heavier. I only had to cut down the springs about 1" to get the right spring rate (0.95), which was just about the thickness of the emulator and the spacer between rod and emulator - perfect.

PLUMMEN wrote:

not to beat a dead horse here guys but ive had good luck just running 30w synthetic motor oil to help take some of the dive out of stock frontends in place of that 10w crap,being the basically cheap bastard i am ive had no problems with it soaking up bumps and doesnt dive nearly as much when hitting the skids hard seems to help keep rear tire on road better when braking

I hear what you're saying and don't get me wrong, playing with spring and oil combinations can make a significant improvement. But...

I really concentrated on front fork performance after spending some time on a friends 04 GSXR600 with cartidge forks. The only thing about that bike that I thought was superior to my old KZ was the front forks. They soaked up bumps so well that the ride was actually plush but not spongy or springy. The KZ was always a compromise. Either too stiff, spongy, springy...until I installed the gold valves.

btw. that gsxr and my kz have about the same peak hp but the gsxr needs to be reving btwn 8 - 14K RPM to use it...It's got nothing below 8K. The kz's got nice meaty torque between 3 - 9K. Way more useful on the street.

As mentioned above by Dutch, getting the springs and oil height/viscosity set-up correctly will have a profoundly positive effect on ride quality and lessen brake dive. If the stock springs can be shortened, to effectively stiffen them, the investment will be minimal too. I know that on my 550 the stock springs are about half as stiff (numerically) as what is recommended.