It’s done! After over a year our frame is rolling on it’s own wheels again. I finished the new suspension strut in the rear and rolled out the garage. For all of you, who are interested in such a swingarm swap/conversion i summarized the whole thing again. Beware, i assume NO warranty for your modifications! I just want to point out what is possible and how it could be done.
Comparison of the two swingarms
FZR 600 (already the pentagonal arm, Deltabox) and the R6 swingarm of the last year of manufacture with model code RJ15. It’s hard to believe, but the aluminium swingarm is not heavier, but due to the tremendous size of course much more torsionally stiff. The R6 swingarm is slightly wider, precisely wide enaugh, that it does NOT fit into the frame.
Bearing shells turned out of steel
The recesses in the middle are purely to save weight, here are the drawings: You MUST NOT forget the M32 fine pitch thread inside! The tangential cut was milled out by hand. They prove to be very useful later, when the swingarm will be assembled/disassembled. Here are the drawings and dimensions of the bearing bushes. (Sorry for quite bad drawing)
You need to work very precisely, to get the new bushings really centered. I installed the old axle and built together a small tool for scribing (on all four sides). The dimensions of course depend on the diameter of the new bushings, you can see this in the assembly drawing below.
Before milling out the old seating, the center has to be measured, since any reference point is gone then. Therefore i stretched a wire from the top down (rasp a small wetch into the frame, where the wire fits in on it’s own), exactly the same distance to the bearing bushing on each side. Afterwards measure the assembly dimensions of the new bushings.
Then, with the angle grinder (and after that by hand) mill out the old seating to the dimensions of your mark.
Caution is advised when inserting the swingarm, so that it is centered in the frame.
I spent a day measuring the FZR 600 frame and YZF R6 swingarm to determine the mounting dimensions, and to ensure the correct tire alignment in the front and rear. Now here we are going to use our artificial midplane (the steel wire in the middle) by measuring the distance to the sockets.
The sockets have the following distance:
- Right socket (clutch side): 127.5 mm from the center.
- Left socket (chain exit): 124.5 mm from the center.
ATTENTION! The drawing view is from front to rear. So you look from the steering head to the rear tire. In addition, you can also see the diameter of the sockets which are needed for the cutouts. After fitting the sockets only tack-weld them. Before welding screw/fix the swingarm with all distances. This way, the welding distortion can be minimized.