Rockshox SID RLT Dual Air Setup

Ive played around with various combinations on +psi & -psi but I’m struggling at the moment with high speed compression (I think) the type of fast constant little rocky hits (rough cobbles type of thing) the fork doesn’t seem to be damping, rather just shaking my hands and fingers. I’m getting some right pain in my fingers with the shake, which is lasting long after getting off the bike.

The forks are the Poploc version with the Floodgate adjuster (no compression adj) on the top of the leg. Any advice would be really appreciated as how to set the fork up correctly as I’m struggling to find a definitive guide other than sticking both air chambers at the same pressure as Rockshox suggest. This creates a little harsher ride than I’m after, hence putting a bit more negative pressure in there.

I weigh 72kgs and have the forks at +90 -105

Also some guides say to set the sag while kitted and seated, others say it needs to be done in the Attack Position….whats the correct position?

ps. the forks are pretty new and running smooth.

Same issue here with the same fork – equalise the pressure and add less rebound so the fork is more boingy – set sag in attack position (seated didn’t move the fork more than 2mm for me), back off the threshold so the fork moves easily when you lean on it up hills (rather than “only just” as other setup guides suggest)

FWIW 12.5st and 80psi in both chambers.

I’m convinced I have extra sticky seals or oil in the wrong place, its better but still not as smooth as my F120 FIT on t’other bike.

Thanks for your advice

back off the threshold so the fork oves easily when you lean on it up hills (rather than “only just” as other setup guides suggest)

Is that with the fork locked out on the remote?

Yep. The threshold (Floodgate) is there to overcome the lockout in extreme circumstances (rather than breaking the internals).

Well know advice is that it should only just start moving when you have all your weight pumping up a hill. I however find mine much better at a lower tolerance with a faster rebound.

I has the same issue as you before – a harsh fork which sometimes felt it wasn’t doing anything.

I think 15 PSI difference between the chambers is too much as you may lose some travel with that difference; it would be worth starting with them even.

Its funny because I had it initially set up just perfectly, but after some tweaks and not writing down what the perfect figures were it now seems illusive. I have a set of F-series RLC forks with the low speed compression which is a big plus really. Maybe its the Low speed rather than high speed that I’m after.

Its the tiny fast bumps that the fork doesn’t react too quick enough. The big hits are great, that’s if my fingers aren’t killing to much to hold on haha.

I think 15 PSI difference between the chambers is too much as you may lose some travel with that difference; it would be worth starting with them even.

Don’t mind losing a bit of travel at all (better for climbing) as long as its not effecting the internals.

ts the tiny fast bumps that the fork doesn’t react too quick enough. The big hits are great, that’s if my fingers aren’t killing to much to hold on haha.

Thats the High speed being altered by the Floodgate. Back off the Floogate that should help, again same issue for me, agony riding over roots….

I also wondered if the extra negative pressure was leading to the fork packing down TBH.

One guide says…..

“Negative air pressure influences how easily the fork begins to compress. More negative air pressure makes the fork “plusher” in its initial travel. Rockshox recommend matching the negative air pressure to the positive air pressure.”

So whats the point of 2 chambers then haha. Some people say that it is the best system ever for a versatile setup. Rockshox have gone back to a single chamber for their 2013 forks though.

Rockshox have gone back to a single chamber for their 2013 forks though.

Ahem. Don’t believe the hype. Although, I do know people who’ve followed the setup guides to much success.

Although you are the only one I know with the exact same fork as me (RLT). Maybe there’s a link…

Yeah maybe there is a link. I’m going to have another fiddle tonight and see what I can find out. Lowering the pressure I think maybe the first port of call.

Have a read of this:

http://forums.mtbr.com/shocks-suspension/floodgate-please-explain-157503.html

It seems to support my own theory that running the Floodgate “less” is better for smaller hits, but won’t allow the fork to lockout as much, which is how mine works now.

So you back off the Floodgate, but run 2/3 click of compression (your remote) – THAT coincidentally is how I run mine – I set my compression until I can hear / feel the resistance in the damper, then back it off one click.

but run 2/3 click of compression (your remote)

That’s where mine and yours differ. I don’t have the remote with the compression on the remote, just lock-out or open. I don’t have a compression adj at all separately. I think its all controlled with the neg pressure and the Floodgate adj.

Got it.

Its more so the Floogate that’s your issue then. Set Sag, back it off and you should be OK.

Yup I’ll have another go at getting it right. I’ll set the chambers equal to start with and then adjust the neg chamber if small bumps are not being soaked up.

Whilst not the same fork I have dual air revelations and find they only need 5 PSI extra in the negative chamber to be buttery smooth and apart from being on the road I leave the fully unlocked.

The 2013 forks with a single air input in my opinion lack feel and adjustability.

Just to add my experience

I have a 2011 Reba RLT and find that I need a little less pressure in the -ive chamber than the +ive. I run 110 and 100 PSI most of the time, maybe a little more +ive if I’m riding somewhere a bit rougher.

This set up gives me around 20% sag in the attack position and makes the fork nice and plush for bimbling along the trail.

Where I may differ from most though is that for a fast jumpy decent with a few drops and “features” I will lock the fork out but set the threshold to allow the fork to move when needed. This combined with a little less rebound damping seems to stops the fork getting bogged down too much with repeated hits.

Hey thanks for the experiences. I’ve lowered the pressures to 85/85, I’m going to ride in to work and take the shock pump so I can make some adjustments for the ride home, then repeat and repeat I guess.

2011 SID RLT 120mm here, non-remote lockout. I’m about 82kg on the bike, and currently run 70psi positive and 100psi negative pressures (gives me 20% sag). It’s still giving its full travel if pushed hard enough.

High speed compression set about 2/3rds of the way through its adjustment (up from nothing) which lets the fork lock out (unless you’re really honking) but still deals with the small hits ok.

Low speed compression usually 3 clicks up from nothing, rebound somewhere in the middle. HTH.

That’s a massive difference in air pressures. Is that 20% sag with you off the bike? More neg pressure will pull the the travel down. I’ll give it a go, open to any suggestions as I’m a bit if a novice when it comes to how forks work.

Sorry – nonsense on my part (knackered) just checked again with the gauge and it’s 80 psi pos and 70psi neg – apologies for any confusion (off to bed now!!).

The figures I quoted earlier will give about 30% sag (very plush initial feel – but it does blow through the middle of the stroke before ramping up again at the end) I’d tried it a while back to see what the geometry would feel like with a shorter fork. Again, apologies for the confusion.

Well tried the 85/85 and it wasn’t too bad, still not as supple in the initial stroke as I would like so I up’d the neg chamber to 95, this is noticeably better now but as the fork is being pulled down, I had to ram up the rebound to stop the fork it bogging down and being lifeless. In fact I ran out of rebound.

Did you back off the floodgate?

If it’s packing down just add 5 to both chambers, starting with the positive.

so 90/100.

As a rule, the negative chamber shouldnt be more than plus/minus 15 psi over the positive chamber.

edit * dubble *

Did you back off the floodgate?

Yeah backed it off and to be honest it didn’t seem to make a massive difference only to the blow-off effort not the ride quality.

If it’s packing down just add 5 to both chambers, starting with the positive.

If packing down is where it didn’t have enough spring to get me off the ground with any finesse then yes it was packing down.

plyphon – read the links / google. In a bizarre way the Floodgate also seems to act as a hsc damper. Having too much will = lack of response to small bumps – which is the OP’s issue. I had the same issue and with the FG on 1/2 to 2/3 my fork is so much more reactive.

Its a weird one for sure – its seems to affect some people / forks and not others, but its worth a go. It makes a difference on my SID with the LSC / lockout fully disengaged.

Stevo210 – when you say you rammed “up” the rebound – do you mean you made it less springy or more springy – try more springy!

I redacted that post as my forks are Rev RLT so ultimately it could all be different as you suggest.

Stevo210 – when you say you rammed “up” the rebound – do you mean you made it less springy or more springy – try more springy!

turned up the springiness to its max and still the forks was not as boingy as I would like.

By adding more to the negative chamber it forces the rebound to be increased to compensate, maybe this is where the Floodgate adjustment might help.

How are you stevo210
i have my settings wrote down at home, but also evertime i tinker i let pressure out of both chambers and fill one specific one first (can’t remember which one) i look tonight, also i’am running 90/100 at 78kg (ISH) give or take 10kg haha

Hey up buddy, these are driving me potty!! be good to compare. Let me know how many floodgate thingy clicks and rebound.

I do the same as you…both chambers completely empty before adding, depress the valve and compress the fork the full travel to get everything totally out.