This story starts at Max Speed Cycles in Kernersville, NC. The owner, Jim, has set up a lot of track bikes and is a suspension and tuning wizard. I asked him about front end conversions for my GPZ900r and he laughed. As a fellow dino-rocket enthusiast (his wife has a CB-1 and he has a VF1000 Interceptor along with a dozen other bikes) he said to install gold valve emulators and straight rate springs. He said KEEP THE BIKE STOCK (LOOKING). I was skeptical, but he promised with the right setup, the bike wouldn't be the limiting factor in the equation anymore lol.
The only problem with the equation is Kawasaki's AVDS (anti dive). To my surprise, the gold valve rendors that setup useless and installation was pretty straight forward when paired with new straight rate springs.
Since the GPZ is about 520lbs with fuel and 200lbs aboard, I opted for 0.95kg/mm Sonic Springs. Excellent quality for $97 shipped to my door. I asked Jim how to set up the gold valve and he said about 3 turns of preload on the gold valve (blue springs) and 15wt fork oil.
After all was said and done (cutting the preload spacers, 120mm fork oil level, fork seals, putting new o-rings throughout the anti dive unit and forks, drilling out the damper rods, etc.) the endeavor was close around $300. WORTH. EVERY. PENNY.
One test is to ride in the middle of the road and hit the reflectors. YOU NEVER FEEL THE REFLECTORS THROUGH THE BARS. The GPZ used to be so much rougher to ride than the 919, and now the GPZ is simply amazing. I can't get over how much of an improvement a properly tuned suspension is. Even with the 16" front wheel that is often cursed more than praised, the bike handles wonderfully. Now I'm researching how to get a better rear shock under the dino-rocket and really have a nice ride