Kawi2strokes.com Forum

PK: right on the money
Most emulators I come across have spring loaded high speed, and and needle-adjustable lowspeed damping.
Such upgrade is most important during high speed cornering when rippled surface is encountered. For sensible streetuse on an old dynosaur it just looks cool.

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Speed is what’s life about.

Leo & PK thanks for weighing in on this. All this talk of little holes, big holes, too many holes, not enough holes, brazed, bonded or stretched holes kind of reminds me of…….ahhh never mind.

So what is the consensus….would you guys or would you not modify the bottom holes in this fashion. We now move from to the next subject, Fluid dynamics….

If you have steel damper rods, which were fitted from 1974 onwards, closing two of the four compression damping holes and resizing the remaining two to 6.3 mm (1/4") plus the modification Leo describes to the rebound damping holes is an inexpensive and effective upgrade, tested by Leo on the racetrack if I remember correctly.

I was lucky enough to find an S&W damper rod kit for the Z-1 which is a drop-in upgrade for H1 and H2 as well. Unfortunately these kits are no longer being made as S&W is out of business if I'm not mistaken, and are as rare as hen's teeth.

thanks Gerrit, so to be clear resizing the two holes is the way to go, we are not really going for total area of the holes as much as two small and two larger holes serving a particular purpose?

Not trying to beat a horse here just trying to understand the task at hand, this is how i tend to work best.

There are four holes at the bottom of the damper rod; these are the compression holes and two of these have to be shut and the other two drilled to 6.3 mm. Further up the rod you will find two smaller holes, these control rebound damping. Close one, resize the other to 1.5 mm. No further mods needed, reassemble and have fun!

These instructions originated from "Cycle World" who tested several forks assemblies in 1976 (from memory their July and August 1976 issues) and recommended alterations to improve the ride. In this case the instructions were for the Z1, but they also work on S3, H1 and H2 damper rods.

Just one question docrick.
Are you installing gold valves or are you modifying the your forks without gold valves?

PK

Installing gold valves PK

In that case follow their instructions, the instructions Leo and I posted are for damper rods without the cartridge emulators.

I second that, and the layout of the holes are not important as long as you get enough area and doesn't compromise the strength of the rod. I like the oval holes that jcsnook did, and I would have done the same if I had access to a mill when I did mine.

Gerrit and me, we are Dutch so we prefer to take the low cost route: upgrade available standard parts as described.
By adding another piece of (modern) technology (goldvalve) the function of the restrictive holes in the stock damper unit should be made ineffective, thus enlarged.

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Speed is what’s life about.