Anyone had problems with setting up the sag on the SID XX forks? Unless I have less pressure in the lower leg (60psi) than the upper (100psi), my forks seem to drop 20mm. Am I being stupid? I always thought that the pressures in the top and bottom legs should be the same?

I set one of these up for a mate a couple of weeks ago. Exactly the same problem.

Ignore what is supposed to be, just put the correct positive pressure in (with nothing in the negative to start), then add a bit of negative. Think we ended up with 100-105psi in the positive, and less than 60psi in the negative, yet they were still ultra plush and returned as good as all 100mm of travel.

Completely at odds with all Rockshox Dual Air forks I’ve messed with before, where you set the negative up at equal pressure like you say!

Similar thing. The neg in mine is only acted lower but I was suprised to find I only need 70 psi in mine – compared to 115 in the rebas that they replaced. Nice forks when they are set up though – although I’m checking the oil levels in mine ( well the lbs is! ) later tuis week.

In order to get sensible sag, I have significantly more positive than negative in my sid team. Difference much more than my same year reba team fork. I imagined it was to do with the inside of the left leg/air spring being much shorter on the sid.

I believe you should always set the sag with no -ve pressure, it’s all down to the +ve pressure. Then add air to the -ve. I usually add just enough to make the travel pull down a millimetre or so.

I’ve always setup/run SID’s, Reba’s & Rev’s with 85-90% of the recommended pressure in the +ve side and then 75-80% of that in the -ve side.
Tend to run my forks on the softer side to keep them active, but the don’t move too much climbing once rebound is tweeked, sometimes a bit of Magic Gate helps.

Same problem Here

Thanks chaps – glad to know I’m not going mad or they’re not knackered. Gave them a bit of a tweak tonight and looking forward to first ride at the weekend!