FZR600 Front End
Installing the FZR600 Forks
Now that the RZ forks are completely free and the old bearing races have been removed, the FZR600 fork can be installed. There are two main hurdles that need to happen: 1. The steering stops on the FZR lower triple are not the same as the RZ triple, and the steering lock will no longer function due to a much lower ignition switch location.
The first step is to mount the upper and lower tapered bearings which I bought through Spec II. I wish I had written down the model numbers but I installed them before doing this.
I found the easiest way to fit the lower race was to place it in the bottom of the frame steering tube and use the previous bearing race as a hammering surface to gently tap it in to place.
Both races should face so that the bearing diameter closest to the triple is larger. I tapped equally at 0, 90, 180 & 270 degrees of the old race so that it went in squarely. The same situation worked well for the top too.
Now that the races are in I installed the dust seal on the modified FZR triple with an RZ stem, followed by the lower tapered bearing.
At this point I installed the triple without any grease and followed it at the top with the upper tapered bearing, collar washer, and finally the stem nut just finger tight. I used the same ignition switch from the RZ which is a perfect fit and then installed the upper triple and tightened the upper stem bolt finger tight to see how the steering stops and steering lock would work.
Well - neither one worked. It turns out that my RZ frame stop was a little bent presumably from a crash from a previous owner. Even if it wasn't bent the stops would have been off. I found it turned to the right so much so that the upper triple touched the tank, and to the left so that the triple stopped about an inch from the tank. I actually temporarily fitted the fork tubes for this test to make sure the lower and upper triples worked together.
To resolve the steering stop I measured an inch from the tank when turning to the right which worked out to be about 1/4" of material that would need to be added to the left hand side of the frame stop. My welding isn't great but I figured this didn't have to look pretty. I used some scrap metal and got it down to the size I needed with a bench grinder then clamped it in place with Vise-Grips. In a perfect world I would remove the bearing races but I was using a MIG welder which goes from nothing to "hot" immediately. I did very small tack welds to hold the piece in place and cooled the metal with a sponge in between. As far as I can tell there is no damage to the new bearing race, and I was only welding to a tab off the steering stem, not the stem itself.
The next issue was making the steering lock work properly. The RZ's ignition key is mounted much higher on the upper triple than the FZR so even though the ignition switch fit well, when the lock pin was extended it didn't catch anything. I took some initial measurements, found some old 2x2x1/8" steel tube and cut one side off to make a tab. I then turned the upper triple to my one inch from the tank mark, moved it back a hair, and noted where I would need to weld the tab. I disassembled the forks and got to welding. I was able to use the existing tab and simply add to it as shown. Works like a charm.
Above is a finished shot at the modifications with the steering stop smoothed and ground down and both tabs painted black to match the frame. Again, not the prettiest work, but it will do its job and it really won't be seen once the headlight is in place.