Thanks yeah I was more wondering if there are any rules of thumb people will follow for this. Just hoping to find any short cuts I can.Since you're already rebuilding your own shock you've got nothing to lose by experimenting.
Go too low and the damper will ingest air at a fast rate and foam up the oil. Go too high and you get more seal friction.
The ISX6 was a victim of the dark days of Manitou where some stuff had SPV internals, some stuff had shim stack internals and the stickers and tuning guides didn't differentiate.You could use the ifp pressure as a tuning tool on the old manitou isx6.
I'm sure Dougal will correct me if I'm wrong.
I think stock pressure was 100-150, but allegedly you could go as low as 50.
This is only relevant as I got to try a ton of pressures.
It is very obvious if the pressure is too low.
The damping pretty much disappeared.
So try a few pressures, you'll know if it's too low pretty quickly!
this depends far too much on the amount of compression damping on the main piston (and on the basevalve) or overall compression damping forces. So no general tips here.Thanks yeah I was more wondering if there are any rules of thumb people will follow for this
The best thing to do is get a Vorsprung Tractive tune as the base valve gets altered specifically to create enough back pressure for a lower IFP. At 200psi in an air shock I would be a little concerned about sucking air in, especially if you run the LSC adjuster quite open.I have a super deluxe ultimate 2020 that I always found too firm. I finished revalving the compression stack to the lowest setting as per rockshox suspension manual someone else posted here. Stock IFP is supposed to be set at 250 psi. I am wondering how low I can reasonably go if I have my air can set at around 100 to 110 psi for 30-35% sag. I want to make the end stroke a little more plush as it is still slightly too firm after the revalve. I am thinking 190ish should be no problem at my weight. Can I go down even further? Any suspension gurus care to chime in? Thanks!!
Thanks for your response I appreciate it. I changed the compression tune from "L" to "LC" which is the lightest one in that rockshox manual. I also changed the standard M rebound tune to a linear digressive M tune also in that manual. Reason for this being the standard M tune supposedly has a preloaded shim which prevents the HSR from opening under normal pressures making it moot.The best thing to do is get a Vorsprung Tractive tune as the base valve gets altered specifically to create enough back pressure for a lower IFP. At 200psi in an air shock I would be a little concerned about sucking air in, especially if you run the LSC adjuster quite open.
A few other points -
IFP pressure isn't really supposed to control end stroke force, you are better off removing volume spacers or changing to a coil shock.
The closest "rule of thumb" I have is most piggyback shocks operate OK at 200psi if I'm ever not sure, but don't go below that without some extensive testing. An air shock has even less room for error as the air spring pressure is also trying to force its way in.
Did you change the rebound too? In my experience, more often than not people diagnose their own rebound problem as compression damping or compression problems as rebound damping. With such a low pressure the shock will easily ratchet down in to its stroke where the spring force is higher.
