Racetech emulators and shock question, Pointy.

This is Race Tech's diagram of pressure and flow during rebound. I was wrong about the emulators controlling rebound. Rebound damping is unchanged from original, and is altered, if needed, by oil viscosity changes. Then of course you will probably have to readjust the compression settings to compensate for the altered oil viscosity. It looks like if you weld up the rebound hole, their isn't much chance of oil getting out of chamber "B" during rebound, just leakage past the check valve?
I don't remember what viscosity RT recommended for my SV650 installation, it was I think 9 years ago that I installed them, and I can't find the paperwork. I really do need to dig it up, as I should change the fork oil. Hadn't realized it had been so long...
Damper rod forks existed long before the SV was created. It certainly wouldn't take much developmental testing to set emulators up for a "new" bike. Maybe they didn't do any. Nevertheless, installed as per the instructions, they work really well.
Found it! RT says 20 weight oil for my setup, 130mm oil level.

[yorkie_chris]

Yes just lots of leakage, it's a really baggy fit between check valve and o/d of rod.

So, how thin does the oil have to be in order to not make the rebound too slow?
And then, how tight do you have to wind down the emulator valve spring?
And, how is the final setup, when you reach it, better than just leaving the rebound hole open and using more viscous oil?

[yorkie_chris]

Well with 85 springs 37cSt is a bit bouncy. 47cSt works well. With hole closed, YMMV!

Advantage is thinner oils can have better VI.

Thanks. If I ever have a problem with my fork damping fading, perhaps I'll weld up the rebound holes, add thinner oil (with a better VI) and repeatedly remove and replace the emulators to adjust the settings until I get the compression damping right again.