I had an extra pair of rear struts that I told him I'd modify for him to fit Koni inserts. So, here's some photos of the sectioning procedure to install Koni damper inserts 8641-1212 Sport into ST184 strut tubes:

(click photos for large size)


Make a small divot in the middle of the strut base with an awl or nail. Carefully drill through the base with a 3mm (or 1/8") drill bit.


CAUTION: If struts are in good shape, gas/oil may vent. I suggest making a spray shield out of spray spray can lid.

Clean the base with rubbing alcohol, Windex, brake cleaner, etcetera, and affix a piece of tape to the base to prevent the oil from leaking out.


Turn over and mount in vice an angle to keep oil from pouring out after the new cut is made.


For the 8641-1212 Sport, make a mark on the strut housing 50mm down from the securing flange.



Using your favorite cutting implement (I prefer a high quality pipe cutter for a clean flat cut), section the tube on the mark made earlier. PROBLEM: If using a pipe cutter, the spring perch does not allow the pipe cutter to be set low enough to cut on the mark. Make the cut at a location as close to the perch as possible. This ends up being approximately 10mm higher than the mark (i.e. 40mm from the top instead of 50mm). This shouldn't be an issue based on how the strut inserts are installed.



Complete the cut. Remove the inner tube, piston, and piston rod assembly. Drain the strut tube. The shock oil can be recycled with your motor oil.



Turn the strut tube over and enlarge the hole in the base with a 14mm (or 9/16") drill bit as shown.

You're done!



For extra style points at your next road race, scuff the paint with a brillo pad or sand paper, clean thouroughly using a quality degreaser, and paint. I chose Rustoleum Appliance Epoxy paint for it's scratch resistance qualities.