Hey Woo, not sure if you've gone through this thread over at MTBR, but there's ALOT of info to be had:
http://forums.mtbr.com/showthread.php?t=241645
http://forums.mtbr.com/showthread.php?t=241645
sl-ata
- Thread starter vitox
- Start date
Good lord...........gonna have to sit down with a beer in hand tonight for that one.
Thanks man!
The 66 is different due to the smaller air chamber. More progressive or something, u cant really base the two off of each other.
Or so I'm told.
If you bought that air 888, make it a 12 pack.
You may even need a funnel.
Well......to be honest.......I usually have to down a few oxycontin before paying attention to mtbr anyway.....but yeah.........whiskey it is then.
ELTORO...noted
I just submitted a request to marzocchi for some detailed literature on this thing. We'll see what I get.
Kidwoo, the reason that you and other folk are bottoming the fork when it is set up for lower travel is this: When you mechanically change the length of the cartridge by winding down the ata adjuster, you are changing the length of the cartridge from the top; changing the length of a portion of the rod that doesn't enter the cartridge, what that means is, when you are set up for 170mm of travel, the piston inside the air cartridge that compresses the positive air comes no where near close to the bottom of the cartridge, so it comes no where near close to compressing the air found in the PAR chamber; the air meant to prevent bottom out. So your fork is very linear when set at a lower travel setting. This is the same system found in the 66SL ATA, which is the fork I have, and this is the same dilema 66SL owners are in.
Yeah, sorry man! Hopefully you can pull some useful info out of it. I've got my 6.6 on order and I've been doing research for the build. I was really thinking about going with the 66 SL 1 ATA, but after the three days it took to go through the 15 or so pages of issues and franken-fixes, I've decided to pass on it.
Well there ya go........
I'm having a hard time envisioning that bottom out chamber being 'farther' from bottom when the fork is lowered.......but I'm going to read your post continually until it either clicks or I need to go pee.
Thanks man.
edit: what's with the sticky? That's actually bothering me worse
I'm taking this beyotch apart tonight and inflicting some science.
Kidwoo, I'm going to post two pics of the 66sl ata catridge, then try to talk you through it.
The top of the cartridge is to the left. At full travel setting, that portion of the cartridge rod that is outside of the cartridge is longer. It has a longer stroke. As the fork compresses, it will send the positive piston closer to the PAR piston, compressing the PAR chamber air [seen in yellow], which is the bottom out protection. When you mechanically reduce the travel of the fork via the ata adjuster, you shorten the cartridge rod, so as the fork compresses, it doesn't come as close to the PAR piston or it's chamber, so the bottom out protection is never really engaged.
I usually run my 66 at 140 to 150mm, so I'm in the same boat as you.
The top of the cartridge is to the left. At full travel setting, that portion of the cartridge rod that is outside of the cartridge is longer. It has a longer stroke. As the fork compresses, it will send the positive piston closer to the PAR piston, compressing the PAR chamber air [seen in yellow], which is the bottom out protection. When you mechanically reduce the travel of the fork via the ata adjuster, you shorten the cartridge rod, so as the fork compresses, it doesn't come as close to the PAR piston or it's chamber, so the bottom out protection is never really engaged.
I usually run my 66 at 140 to 150mm, so I'm in the same boat as you.
Your stiction problem could be a couple things. It could be as simple as your positive piston needing to have it's seal greased. Allthough my fork is a 66 and yours is a triple 8, the cartridges should be similar. Here are some disassembly/assembly instructions that I posted at mtbr, along with instructions for removing the PAR piston, which you can ignore at this time:
http://forums.mtbr.com/showpost.php?p=3195344&postcount=350
http://forums.mtbr.com/showpost.php?p=3195344&postcount=350
You're the man renny.
Thanks.
I assumed this travel adjust worked like a talas.....apparently not at all. Kind of stupid they change the travel without changing what goes on in the air chambers.....just the top of the rod.
I wonder if I can dump some oil into the bottom out chamber to reduce the volume and make it start acting more progressive sooner into the travel.
Thanks.
I assumed this travel adjust worked like a talas.....apparently not at all. Kind of stupid they change the travel without changing what goes on in the air chambers.....just the top of the rod.
I wonder if I can dump some oil into the bottom out chamber to reduce the volume and make it start acting more progressive sooner into the travel.
f this fork
Believe me, I have endured much frustration, and much education, from owning my SL ATA. I like the way the fork feels, but I really don't need a second job figuring out marzocchi's design flaws. Yes, they focked up quite a few things. I'd forgive them if they'd admit it...
If you've read any of my other postst in that 16 page long set up post at mtbr, you'd see that I've monkeyed around with this fork a bunch. For a while, I took out the PAR piston, and used the remaining positive chamber in the cartridge to set the bottom out for whatever travel set up I wanted to. Now, I've re-inserted the PAR piston, but I shortened the tether string to reduce the size of the PAR chamber to about half of what it was originally. I like this set up; it gives me good firk behavoir in the 140 to about 160mm travel range.
I don't think adding oil to the PAR chamber will make your bottom out protection kick in sooner; it doesn't change the position of the PAR piston.
Might give that a go. The reason I mentioned the oil is because I was assuming the chamber was engaged at shorter travel, just not as much. Apparently not.
Let me do some homework on what you've got on mtbr.......
I may request your phone number at some point
way to go renny!
woo, oil will work for what you want just remember if you should ever stretch it back to 200mm that you wont get more than 170 out of it.
try with little oil and little pressure diff between the two chambers, that should get you the smoothest ramp up. i would actually forego the par piston and just play with oil level since youll be opening it up anyway. makes for two less moving seals.
woo, oil will work for what you want just remember if you should ever stretch it back to 200mm that you wont get more than 170 out of it.
try with little oil and little pressure diff between the two chambers, that should get you the smoothest ramp up. i would actually forego the par piston and just play with oil level since youll be opening it up anyway. makes for two less moving seals.
Before I tightened up the travel adjust on my 888, I would routinely have to unwind the fork at the bottom of the run to put it back where it started. Sometimes it wound all the way down to 170mm. I never had any issues w/ bottoming out though. I'm 185 running 115/85.
My experience with the internals are just removing the top caps and changing the oil.
My experience with the internals are just removing the top caps and changing the oil.
Any option for removing the travel adjustment feature completely leaving it at 8"?
toby
toby
its not really necessary at least i havent had any problem effectively locking the ATA out, you just need to tighten the grub screws a lot and then you will effectively remove the adjust feature.
Got the cartridge out........it's definitely the source of the friction. Feels like a very defined two stage stroke with one of the pistons sticking like crazy until it's forced to move. Need to get a good clamp before opening it up though.
Kidwoo, when you compress the cartridge, doe you feel a pop; like something breaks free once enough pressure is built up. If so, that is the PAR piston moving. It has a very tight o'ring seal to the inside of the cartridge wall.
As far as a clamp goes, what I did was to wipe down the outside of the cartridge to remove the oil, then I wrapped a tire tube around the cartridge to get a good grip. Then I took a wrench to the top cap of the catridge.
As far as a clamp goes, what I did was to wipe down the outside of the cartridge to remove the oil, then I wrapped a tire tube around the cartridge to get a good grip. Then I took a wrench to the top cap of the catridge.
Im with you.
Yeah there's no question that's what it is. What sucks is I've got two full weekends of lift riding on it and it's only gotten worse. Considering the PAR doesn't do diddly squat for the fork I need (170mm) I'm thinking getting rid of that thing would be fine. I don't see any reason I can't make it a two chamber piston and then just screw with some oil in there to give it some ramp up. That's what I did with my 150mm maverick fork. 20mm more isn't that much different... That's what you're saying anyway right vitox?
How are the other long travel air forks like boxxers, totems (single step) or even the white brothers fork setup?......anyone?
Just with your hands? I'll give that a go.
All i have gained from this thread is that this fork is brutal.
Is the 08 any better? At least, in e-theory?
Is the 08 any better? At least, in e-theory?
Yeah in theory.....
My only problems seem to stem from trying to run it in its low travel setting.
Considering that next years will still be a first year design, who knows....I got the 07 because it fits my go-ride crowns and the bigger stanchions/lowers next year will have to be thinner to keep the wieght the same. If I can get this sticky thing under control, I'll be a happy camper.
yep, id try with around 20 to 30ml for starters.
the 08 cartridge has been lengthened is what i know, will likely cure the travel problem perfectly for those who run it at 200mm, but im not sure about if for people lilke you it will be better.
Kidwoo, just your hand clamping pressure added by the traction of the inner tube should be enough. The cap you are removing has very fine threads; there is hardly any torque on it.
FYI, the set up I ran on my 66 for a while that was with the PAR piston removed; you end up having one large positive chamber that is set-up with just enough PSI to provide the bottom out protection you need, and supplemental spring pressure is achieved by adding air to the other leg. I believe Vitox used this set up for the 888's he worked on.
FYI, the set up I ran on my 66 for a while that was with the PAR piston removed; you end up having one large positive chamber that is set-up with just enough PSI to provide the bottom out protection you need, and supplemental spring pressure is achieved by adding air to the other leg. I believe Vitox used this set up for the 888's he worked on.
There's no way to put air in the other leg on this fork though.
Either way, there's no reason an air fork needs a regular AND a bottom out chamber if the volume of one chamber can be fine tuned (oil in my case)
I'll be trying this tonight when I get done riding.
We're gonna need some more polish!
Haha...But it's def. not a poooh stick fork.
I've hit 50-60 foot dubs and 30+ step downs on this fork when fully lowered and it makes them disappear. I may get a harsh bottom out if I land wrong but never in rocks. It's just a total hit and miss fork.
I messed up Woo I totally forgot to ck what I'm running.
I've hit 50-60 foot dubs and 30+ step downs on this fork when fully lowered and it makes them disappear. I may get a harsh bottom out if I land wrong but never in rocks. It's just a total hit and miss fork.
I messed up Woo I totally forgot to ck what I'm running.
Yeah kind of wierd that this is the only fork in the history of ever that might experience improvement with some tweaking.
:biggrin:
If I can get a 6.5lb fork that doesn't say boxxer on the side of it, I'll be stoked.
Okay.
It works. Getting rid of that annoying, PAR piston engagement is like heaven.
The piston setup looks exactly like what renegade posted from his 66.
Right now at 100 psi, it feels like a good fox air fork with plenty of ramp up......maybe too much, we'll see.
I dumped 30ml of oil into it at first and with no pressure in the cartridge, couldn't get 'full travel'. So I pressed on the schrader valve at the bottom (normally the PAR valve) and pressed on the stanchion till enough oil spilled out that it would bottom. Probably lost about a third of what I put in.
It's immediately an improvement just getting rid of that sticky point in the stroke.
We'll see if I'm getting the full travel this weekend.
It works. Getting rid of that annoying, PAR piston engagement is like heaven.
The piston setup looks exactly like what renegade posted from his 66.
Right now at 100 psi, it feels like a good fox air fork with plenty of ramp up......maybe too much, we'll see.
I dumped 30ml of oil into it at first and with no pressure in the cartridge, couldn't get 'full travel'. So I pressed on the schrader valve at the bottom (normally the PAR valve) and pressed on the stanchion till enough oil spilled out that it would bottom. Probably lost about a third of what I put in.
It's immediately an improvement just getting rid of that sticky point in the stroke.
We'll see if I'm getting the full travel this weekend.
SO...just got off the phone with Gideon at Marzocchi (he's worked on my stuff before, he knows his stuff). He said the "pop" thing from that O-ring will break in with time and to ride the **** out of it and to wait about as long as the normal bushing break in or maybe a little longer. As for the bottom out/not getting full travel thing he said to back the high speed compression off at the bottom of the right leg (I always thought this knob was lo-speed on this fork and on my previous '06 RC2X, but I confirmed with him that it was the high speed) and to possibly just let out some of the oil from that leg. Stock is 210cc and I remember having my '06 888 dialed in at 185cc for that leg of 5w and having a pretty much perfect feel (I weigh 170).
I mentioned the piston removing thing and was told first off it obviously wasn't recommended, and that it would just create one large positive air chambers. Also the bottom air chamber on the left leg (of the 888) isn't a PAR piston but a second positive air according to them.
If it really isn't the high speed compression and oil level I would like to find out a way to make that lower air chamber a little smaller at least so it doesn't ramp up hard at the 3/4 travel mark. Maybe that way I'd be able to keep some kind of warranty on the fork as well...having parts completely removed from the internals probably wouldn't sit real well with the Marzocchi techs if I were to bring it to them in a few months.
I mentioned the piston removing thing and was told first off it obviously wasn't recommended, and that it would just create one large positive air chambers. Also the bottom air chamber on the left leg (of the 888) isn't a PAR piston but a second positive air according to them.
If it really isn't the high speed compression and oil level I would like to find out a way to make that lower air chamber a little smaller at least so it doesn't ramp up hard at the 3/4 travel mark. Maybe that way I'd be able to keep some kind of warranty on the fork as well...having parts completely removed from the internals probably wouldn't sit real well with the Marzocchi techs if I were to bring it to them in a few months.
Yeah it does create one large air chamber........which is why it's better
There's no reason an air fork needs a second pressurized bottom out chamber. Air cartridges are progressive enough on their own.
As far as it not being a 'PAR' piston, I don't even know what that stands for......I got it off their website in describing the lower piston on this fork.
http://marzocchi.com/System/30832/Bomber07-ENG.pdf
Look at page 69.
My friends with this thing stock still don't get full travel with that damping knob backed all the way out.
It sounds like you should shorten the strings on your fork if you don't want to remove it completely. That would engage that piston further down in the travel.
I wish you could feel my fork right now though
I bet that's not all of yours you wish I could feel right nowYeah it does create one large air chamber........which is why it's better
There's no reason an air fork needs a second pressurized bottom out chamber. Air cartridges are progressive enough on their own.
As far as it not being a 'PAR' piston, I don't even know what that stands for......I got it off their website in describing the lower piston on this fork.
http://marzocchi.com/System/30832/Bomber07-ENG.pdf
Look at page 69.
My friends with this thing stock still don't get full travel with that damping knob backed all the way out.
It sounds like you should shorten the strings on your fork if you don't want to remove it completely. That would engage that piston further down in the travel.
I wish you could feel my fork right now though
a little lonely eh?WTF is up with having a string holding pistons in place in the fork? I'm sure it works but it just seems a little cheesy. How would you go about shortening those anyways?
And yes, bringing the air pressure in the top chamber down a little and backing off that knob didn't do anything for that 3/4 travel point so I'm going to try letting some of the oil out tonight, although the ramp up feel is far different than that of my RC2X when I briefly had the oil too high so it wasn't getting full travel - this is much more immediate. I would like to have that ramp up kick in maybe in the last inch of the travel or at least kick in a lot less suddenly and fine tune that with the oil height in the damper leg. I gotta admit the air spring on it feels REALLY nice when you get the preload settings on it though. The Marz tech confirmed the suggested values are quite a bit high and recommended around 100 psi for my weight and I'm still running between 50-55 psi top and 80-85 bottom to get it to feel anywhere near right.
I do like the idea of just removing the bottom out air chamber and using the oil heights in the damper side to control the bottom out and pneumatic lock. I don't really understand how the oil amount in the air cart side would control the travel limit though?
By putting oil into the cartridge, you reduce the volume and hence expedite the point at which it reaches whatever max pressure is required to stop your weight on it.
Something I noticed with mine is that pretty much ANY oil in the air cart makes it ramp up too much.
You can screw with the oil in the damper side to get the good old fashioned marzocchi hydraulic lock but from what my fork feels like right now, I don't think you need to........besides......that just cuts off the last end of the travel which is what most people are having problems with already with this fork.
check your pms........
It wouldn't be hard to shorten the string. All you need is something with two loops on the ends to affix to the cotter pins on the piston. Look at renegade's pics.......it's a pretty simple setup.
Something I noticed with mine is that pretty much ANY oil in the air cart makes it ramp up too much.
You can screw with the oil in the damper side to get the good old fashioned marzocchi hydraulic lock but from what my fork feels like right now, I don't think you need to........besides......that just cuts off the last end of the travel which is what most people are having problems with already with this fork.
check your pms........
It wouldn't be hard to shorten the string. All you need is something with two loops on the ends to affix to the cotter pins on the piston. Look at renegade's pics.......it's a pretty simple setup.
mmm got an rc2x today. suspension movement is great
Hacktastic, that pop sound has been coming from my fork for 8 months now, and has not gone away. Marz. told me the same thing way back when, but it hasn't come to fruition. Also, lack of full travel has nothing to do with the compression setting, or the oil level. You are getting the standard marzocchi tech spiel,. Those guys do NOT understand the SL ATA forks IMO. And of course they don't recommend you modify their forks! That would be heresy.
PAR stands for progressive air resistance. A positive chamber does the same function. The reason the PAR piston is tethered is so it provides a fixed volume and position in the cartridge, so the pressure can be varied with rider weight. You can change the position of this piston. I visited a hardware store and bought some very thin and strong nylon cord, removed my PAR piston, replaced the stock tether with one half as long, to create a PAR chamber half the size of the stock one. I like it.
If you shortened your tether, Marz. would probably claim you voided your warrenty anyway. Any excuse to get out of doing free work. Thing is, you can remove the piston, change your tether length, without doing any irreversable changes to the fork. You can put the PAR piston and the stock tether back in before sending your fork to marz.
Is that deception? That's your call. I have no moral dilema with it; the way I see it, they produced two models of forks that don't do what they are supposed to do, and they bury their heads in the sand about it.
Edit: For a little insight as to what 66 SL ATA owners have had to deal with, check out this thread at mtbr. Skip the first ten pages:
http://forums.mtbr.com/showthread.php?t=241645
so youre all set then?
i always thought for anyone not wanting to run the sl ata at 200mm, it would make a sick fork, full travel attainable, tuneable bottom out, 888 strong and very light.