So I got my Decoy SN29 a few months ago (put about 50 miles on it) but out of the box, the fork was compressed with a velcro strap. Removed that immediately.
I built up the bike, setting sag was my last thing to do after all bolts were checked and bike felt comfortable to start. Immediately noticed the Fox 36 Performance 160mm (29) which had about 65psi in it visually looked like a 140mm fork. Gave it some compressions and heard the sound. You know the sound. Still the fork stayed compressed. I released all air before adding. The fork shrunk itsself when I did that. Began Foxs recommended setup procedure and it seemed to fix the issue… only to a certain extent.
TLDR: New fork, air pressure 82psi, unweighted has about 10mm of “free sag” as i’ve been calling it. Tried adding 3 volume spacers (4total) thinking that would change anything… nada.
What else to try? (SUSPENSION HELP)
byu/everydayaudiophile inMTB
by everydayaudiophile
7 Comments
Try Rockshox
Did you try cycling the suspension periodically as you added air to the fork?
Add 20-30 psi, remove the pump, cycle the fork 5-10 times, add another 20-30 psi, remove the pump, cycle again 5-10 times, repeat until you reach target air spring pressure, cycle again, and top up if necessary. Air tokens won’t change the sag.
Did you try contacting the manufacturer?
Negative pressure. Try emptying all the air, pump it back up high as fack then ease air out till sagging at 10ish% then ride the piss out of it for a couple laps. Slowly ease air out. Saw lots of this at bike park this season. Some are just cooked and look into warranty. As you do this make sure you open and close the compression and rebound dampers as well, don’t do that with pump attached. You are gonna have to plant and unplug your pump a bunch of times but it should work. If not contact fox and they are usually really good about warranty stuff. reset them both to a solid middle before riding.
That small amount is absolutely normal. Your suspension will always sag a little bit under its own weight. (and from the negative airchamber) Also this looks like a few mm, not 160 down to 140mm.
The velcro strap is there to make it fit into the box and shouldn’t hurt the fork at all.
If you are not convinced, take the lower legs off and inspect them or get a small service done at your local bike shop.
If all else fails, and as some people already suggested, try contacting YT, although that might be diffucult right now :/
Edit: Also try to use the bleeder valves on the back of both lower legs to equalize pressure
Fox shocks come from the factory with a lot of grease in them, like way too much. It plugs the ducts and causes a negative pressure build, so your fork loses travel. It’s called fork suck. The best fix is a lower leg build to clean out all of the extra grease. Mine did this too after about 50 hours as well, but way worse because I did a bunch of big hits that bottomed it out. I’ll be doing the lower leg rebuild this weekend.
https://youtu.be/MQBsrTpwoCo?si=-u5eoRlUfSsRSjbo
This is normal. You’re probably just compressing the top out bumper when you forcibly extend it like that. Having a little extra negative travel like that is actually a good thing. It’s indicative of very low or zero preload on the air spring. It makes the fork more sensitive off the top.