AFR Shock Air Sleeve Service
Seen a lot of great information on fork service but none on the shock for my SL. Is the air service the same as it was on the Fox line? Let air out, unscrew canister, clean, grease orings, etc.? Is the Slick Honey Grease the best to use for this service? Is this a good idea to do right away even thought the bike is new?
the air sleeve service is very easy and simple.
remove the shock from the chassis.
( measure the eye to eye length of the shock and record it ----this can be very importaint for later)
remove the air pressure from the sleeve.
unscrew the sleve --( i use a rubber strap wrench -----if you do not have arthritis in your hands you can just screw it off with your hands )
----note that the sleeve will move down and will have resistance ( negitive air or a vacuum in the sleeve and you have to kinda pull hard to get it to come off the shock body.
when it comes off you will also see an o ring left on the shock under the seal head or it may stay in the sleeve , --this is the top out bumper --do not forget it or loose it .
take and clean it all up nicely , ---and put slick honey on the shock sealhead ring, and pack the seal in the sleeve with honey also ------i add aliltte extra honey on the shock shaft --------check out the bottom out o ring inbetween the shims at the top of the shock and make sure it is ok .
no here is where fox does not tell you how to assemble the sleeve back on the body without causing a negitive pressure and actually making the shock shorter after reassembled .
i take a 4" long .004 tho feeler guage and lay it on the shock across both seals areas at the same time,
then now slide the sleeve on the shock right over the feeler guage, and while you are sliding the sleeve on you are causing a leak at the feeler guage and the sleeve will go all the way on and not have any back pressure pulling the shock shorter,-
then pull the feeler guage out , ------air your shock up to your running pressure, --and then measure the eye to eye length of your shock and make sure it is at your running length ,
and you are ready to go !!
it is really simple.
most of all the fox stuff i get is assembled wrong and the shock does not have full travel like it is supposed to because they do not correctly bleed the sleeve on assembly.
there other ways to assemble and bleed the sleeve on these air shocks.
but in the feild , the .004 feeler guage works very well
Thanks for the help. Are there concerns with cutting the oring in the process above. Should the same be followed on fox shocks. I have seen what you are talking about but it seems like the fox shock was only shorter until air was pumped into it. Would installing the sleeve while depressing the valve stem have the same impact.
Thanks again for the detailed writeup.
Just to be clear on this bleed process. You lay the feeler gauge on the shock shaft, along the shaft and slide the shock air sleeve up over the feeler gauge right? On my fox shock I had a couple questions that I assume would apply here. The seal for the air chamber is between the large o-ring and the inner surface of the sleeve. When I had my shock serviced last, I told them it seemed to loose a little air over time. They replaced the shaft also (pretty cheap at $20) and had circled a tiny scratch on it stating this may be my leak problem. Realizing that the seal is above this, that story doesn't make sense. Also, the seal you are bleeding the air from is only a dust seal, right? Does air normally move past this seal during operation? When the shock compresses, it would seem this would form a vacuum if it was air tight.
the bottom chamber is air tight , that is why you can trap negitive or positive pressure here and really affect the shock length and how it function )
Originally Posted by jason8265
when the o-ring on the seal head leaks and lets pressure into the bottom chamber it will cause your shock to stick down ,-----this can be caused by several things ,------but generally when a shock leaks , ( wheather it be from inbetween the two chambers on the air sleve , or when the nitrogen charged seal in the head leaks and dumps in both chambers on the sleve )
it is because the shock has not been taken care of and just ran to deth .
i really can not believe that mountain bikers will go a year or more whithout servicing their forks and shock .
( these componets get beat all to hell )
and really need to be taken care of alot to keep them from wearing out and performing badly.
generally when a shock leaks the air sleeve "ride height" air , ---it is because the shock has ran so long that all of the slickhoney has worn off of the two seal areas in the sleeve and the air can go from the upper chamber and weep right out into the lower chamber and right out the lower seal .
small nicks in the shock body are not good but generally generally do not pose a huge problem.
( the big thing is to not let your shock dry out and ruin the air sleeve seals, the seal head seal, --and or score the shock body with a dry air sleeve seal .)
on bleeding the air sleeve, i like to lay the feeler guage along both the seal head o-ring and install the air sleeve on and let the bottom seal in the air sleeve also run right on this feeler guage and push it all the way up to the threads and i will spin the shaft by the upper shock eye and screw it all together and then slide the feeler guage out the bottom , ---and now you have bleed both chambers of the sleeve and you done .
any ideas on how to do bleed the lower air chamber on a Swinger 4 way without a total dis-assembly? I can't slip a slim feeler gauge under the seal due to the additional oil chamber being in the way.
i do like that old manitue swinger 4 way shock , they do work very well !
Originally Posted by PB Matrix
i was able to slip a 35mm film negitive up in the bottom seal while it was still on the body and shove honey in the bottom by the negitive and then i used the negitive as a guide for my feeler guage in the bottom and it bleed good while i slid it up into place ,--
i was going to slide another feeler guage in through the top of the air sleeve , but i did not need to .
Thanks for all the help. kelstr, if you do this in the near future can we coax you into posting a pic. For some reason the feeler gauge make me nervous for scratching or cutting the seal/shaft but I think I am picturing this wrong as I am in no way doubting the expertise I am getting. Could this also be done with a flattened straw as the plastic would help on any scratching concerns?
a straw, ---you know that is a good idea, i have never tried one , but it would be worth a try .
i have use a 35mm film negitive , -if you cut the negative down to a 6mm wide strip
it will work generally .
ill have to get some straws and have them here and try them !!
?! I've serviced a lot of Fox shocks and never had the stated problem. What I find happen is that when you initially pump the shock up some of that volume will bleed into the negative chamber until the pressure is equalized. While not criticizing Kelstr's technique I find it unnecessary unless you don't want to wait for the air pressure to equalize. Just my 2 cents.
the one big difference on the AFR and most of the newer fox shocks, is that there is a rebound bump stop o-ring that will fit perfactly in the lower section of the air sleeve that is fixed to the botton of the seal head and when the shock is exspanded , the bump stop 0ring totaly seals off the area and the shock will stay 3/8" shorter forever.
some of the fox shocks that do not have a bump stop will still stay shorter for ever also.
i can not tell you the shocks that i get in the shop that are partially stuck down because they were assemblied with to much negitive air .
also this is one problem that sticks a shock down, ------the pumped in "ride height air" will get blown into the lower negitive side when the seal gets worn and totally stick the shock compleatly down , ----and they never equilize or come back up.
this is why you always want to check the installed height (eye to eye ) of any shock you are servicing, ----and make sure when you are done the shock is the same height you started with
All right, I did this service today and had some trouble. I used the straw which worked pretty good to bleed. The first couple times I slid the sleeve up I didn't have it all situated and so I tried a third time and that when the problem started. The sleeve would not slide over the main seal in the top of the shock. I lined it up carefully and it seemed that the main seal between the two white bushings would push up and the upper bushing would expand and not allow the sleeve to slid over. After about an hour I finally got lucky but not until I had removed the bushing pieces and the seal to try and figure it out. Once I did that it still took several times to get it. Has anyone had this problem? Its all together and seems good to go but it was a true pain in the butt.
generally this is not an issue on a shock with a seal set that has been already installed ,
you can help the sleeve slide into place by gently rocking the sleeve side to side if you have troubble getting the sleeve to slide over the seal,
there is also an assembly tool for automatic transmissions ( a lip seal tool , --its a .004 tho feeler guage ) that you can use it like a shoe horn to het a seal not roll and jam on assembly,
you can also put the seal in the freezer and get it cold if you are having troubble,
but like i say , generally these things will slide right on with enough slick honey and some carefull determanation !!
I know this is an old thread, but I just performed this shock service on my bike today and wanted to share my experience.
It all went smoothly except for one part: the bleeding of the air sleeve when putting it back on. I tried a drinking straw, a thin zip tie, a shifter cable, and a feeler gauge, but couldn't for the life of me pull any of the aforementioned items out after getting the desired "bleed effect." The air escaping was audible, but the seals were so tight that whatever I put in there for the bleed just stayed wedged in there. I'm actually pretty lucky that I didn't do any damage to the seals, because I was struggling with this procedure for at least 2 hours.
I ultimately gave up and threaded the air sleeve back on without making an attempt to bleed it, figuring that my shock would be too short from the negative air pressure, but I would at least be able to go for a ride. Surprisingly, my shock was not too short at all. My eye-to-eye measurements weren't necessarily the most precise, but as far as I can tell, my shock is maybe 1mm shorter than it's supposed to be, but it runs a million times more smoothly than before. No initial stiction, and really smooth throughout the entire stroke. Needed to up the air pressure in the shock about 5 psi to compensate for the new-found lack of friction.
Just got back from a 3 hour ride on the newly serviced shock, and it's like I'm riding a brand new bike. It actually feels like I have a full 6 inches of travel in the back now, and it's much more supple than before.
I'm "bad" different
i just got my bike back together with everything slick honey'd and it's almost too active! unless i really have the compression damping turned up, standing and cranking causes more suspension movement than before. i might try some green loctite on the dust wipers to compensate.
One thing i did notice when putting the bike back together was if I torqued the shock bolts to spec, the plastic spacers on either side of the shock eye got clamped to the point that the shock did not want to pivot smoothly. This was especially noticeable on the bottom mount with the two tabs welded to the frame. I figured the reducer sleeve would get clamped solid before any significant pressure was applied to these spacers, but they were definately squeezing the shock and causing rotational drag. I cleaned the bolt threads, applied new loctite, and tightened the bottom bolt while pivoting the shock (not attached at the rocker) until there was zero side to side play and minimal rotational drag. I then installed the upper bolt to about the same torque. I figured what's the point of getting my shock moving real slick if it's just going to stick at the eyes?
Glad to hear your service went well. This is why we recommend the service intervals. Suspension is a very dynamic component that sees a lot of hard use. A basic air sleeve service on your shock and a lower leg maintenance on your fork @ regular intervals will keep the suspension working at its peak performance until a full service is needed.
For future reference; the bleeding of the air sleeve is not a required step in a basic air sleeve maintenance.
Haha yeah... After my absurdly frustrating experience today, I'm gonna be skipping that step in the future.
Originally Posted by Speci- Suspension Tech
it is amazing how well the shock and fork work when they are kept serviced .
the shock is so easy that once you get used to it , you can do it very quickly-----and you can very the amount of trapped negitive pressure in the shock for a different feel ----.
i have been trying a different amount of negitive pressure , and a slightly different length shock untill i finnally got the feel i wanted for me.
i even left the "o" ring off from under the air sleeve so i could trap more negitive pressure and slick honey and still have the stock length.
7"15/16's is the fairly normal length ------( thats right at 5cm and 6mm of shock shaft sticking out the bottom of the shock)
if you do not bleed the shock at all , and you use alot of honey and you have the "O" ring in the shock-----you can be 6 to 7 mm shorter .
so you end up with 5cm of shock shaft sticking out ----and this will slaken out the ht angle more and you lose travel.
so its good to really measure and know just where you are at.
the other feature about trapping some negitive pressure that i like is, ---the shock breaks into the travel easier from fully extended ,
this gives it a better small bump absorbtion .
the other thing i noticed ,----is with negitive pressure pulling the shock down , you must use alot more positive pressure to get your ride height -----( i will go from 123 with a stock shock , to 140 with negitive pressure in the shock)---
and this really helps the bottoming resistance big time ---------but yet the shock stills breaks into the initial begining part of movement easier and is smoother
i will weld up alittle schradder valve assembly of somekind to the lower portion of the air sleeve so i can add and subtract the negitive pressure at will and be able to use it as a tunning tool easier .
the AFR of the future should have this tunning option !!
"i will weld up alittle schradder valve assembly of somekind to the lower portion of the air sleeve so i can add and subtract the negitive pressure at will and be able to use it as a tunning tool easier .
the AFR of the future should have this tunning option !!"
I disagree. You know KISS right? "Keep it simple, for stupid" there are already to many adjustments on the shock as it is. Adding a negative chamber adjustment is going to further confuse the layman and if they add to much - air pressure it will counter act the spike valve's function. My shock works as designed with zero negative pressure and stays locked till I need it, Lower tire pressure takes care of the small bumps on a rear tire.
Anyone take any pictures while doing this AFR sleeve service? Would love to see some pics before I give it a go.
you are correct PB ----i do see alot of guys that have the negitive and positive pressure adjustements on their suspensions and they do get it all confused.
Originally Posted by PB Matrix
this is really only for a guy that needs and wants the option , --.( i am kinda queer and like to see what i can and can not achive )
most guys will really like the shock with the negitive side all bled out like it was stock,---
the AFR does work very well and is a great design !
you gotta admit ---this AFR on the enduro works very well and the pedaling platform that is in all the compression ranges does work very well .
there was an article in Mountain Bike Action magazine done up real nice with pics and a good write up .
Originally Posted by solara
it was april edition i believe ( of course i can't remember time very well so it may not be april )
and i think that Fox on their web site has some kinda ok drawings and instructions on doing this air sleeve service on air shocks also !!
Come on Bro...post some pics!!!
I've been following your post on several forums and you seem like the most knowledgable tech/mech out there. Thanks for you time and attention! Please...please...please, can you post some pics so mechanical idiots like me can do this service with confidence (including the negative air bleeding steps)!!!
Thanks in advance,
PS, I ride an XL 2007 Enduro SL Expert and I am 230lbs with gear, do you have any tuning tips for guys my size?
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