I test piloted a set of YSS PD valves(cartridge emulator) in my CZ forks on Saturday;
Cartridge emulated CZ forks = GOOD!
Huge improvement noted when front braking hard into a corner with plenty of braking bumps leading in. Overall dramatic improvement in damping - the forks just feel right & now the backend feels harsh.
Stock CZ's are not the easiest of things to do this to, the stock fork legs have an area of heavy wall in the fork tube where it clamps to triple. My bike has new fork tubes from NWCZ&Maico that I've been running for a couple of years now, these tubes are smooth bore all the way inside - 29.0mm I.D. Also I have the CZ "trickit" dampers so had to cut adaptor cup/buckets for the emulator to match up to damper rod.
The valve as supplied was 29.0mm O.D, so I had to machine some clearance around the valve to get it floating free in the tube. I had been using CZ fork springs which are small at the outside diameter(see previous note about stock CZ fork tube). These could not be used with the new valve as they mask the oil flow thru valve, I found a set of Honda XL250/350 fork springs & installed these larger O.D springs instead. Changing the springs has also meant that I don't hear that annoying "spring scrape" that I used to hear when compressing the forks.
Anyway this has been a work in progress(slow - hey ya gotta have time for a beer too) for some time now & I'm happy to report these forks are sweet, next weekend they will get full battle field testing conditions at the NZ Vintage champs round 2.