Totally sounds like air in the cart, especially with the symptoms of no low speed compression. You're going to get dive dive dive until oil starts going through.
Avalanche boxxer upgrade kit out! Will fit majority of forks!
- Thread starter bullcrew
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Slipperysalmon have you managed to fix your problem? I have the same issue. When the forks are on the bike the noise happens when compress the forks fast only a couple a of inches. when take the forks off then its exactly the same as yours? Any experts on here got any ideas? I have 100% correct amount of oil. I will strip the forks and take cartridge out but when i do is there anything in particular that i should look for / check?
The lock ring is correct way round but as said the noise happens when on forks are on bike and only compressed one - two inches but fast so it cant be anything to do with bottom out cone as that wouldnt have engaged yet. Any help would be much appreciated.
The lock ring is correct way round but as said the noise happens when on forks are on bike and only compressed one - two inches but fast so it cant be anything to do with bottom out cone as that wouldnt have engaged yet. Any help would be much appreciated.
Bleed it. If you are still having problems with it, I want to buy it from you guys. 
T means air side and hes just trying to snag it from you lol
I get a little noise from mine on damper side its a swish noise but that's normal. Energy from friction does 2 things during the process as far as releasing energy it heats up and noise.
It means the internals are doing there thing, besides I don't hear mine while riding and my bike is literally almost silent so no biggie.
As far as the noise in the first 2+"s I have no idea if its not too low oil then it would have to be something loose or moving obviously. I'd be curious to see the cart out and apart to look for tell tale signs, I have 2 carts and no noise my 3rd is on a buddies bike in the 66 and no noise there either. Descent on here has a cart in his boxxer as well and its silent aside of the mild swoosh. Even my talas 180 goes swoosh.
Just thinking about it, check all the connections inside like the red one under the cap and make sure they are snug. Pull the cap compress fork and holtd the cart extended wiggle it back and forth to see if there's play. Cycle the cart up and down by the top cap the first couple inches while the fork is comprssed and see if you can get it to do it.
Just listened to the video and aside of it hitting the bottom out it sounds like suck back from too little oil like a void in damping.
Check the parts to make sure everything is tight though.
Just listened to the video and aside of it hitting the bottom out it sounds like suck back from too little oil like a void in damping.
Check the parts to make sure everything is tight though.
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just felt like checking in. i threw some fox SKF 32mm seals in my boxxer, and with a fresh dose of golden spectro it feels RIDICULOUS
Andy you got any 35mm skf seals in stock? Yeah just slapped a cart in my new wc so the oil is still FREESSSSSSSSSSH. Not that my 18 month old oil was bad last time lol. But yeah clean oil is nice and smooth.
Right i have done some more checking and i think its something to do with the high speed rebound. The reason is that when i remove the top cap i can still get the rod to make the sound when compress the rod slightly and pull quickly. When the fork is assembled the noise/knock occurs when the fork rebounds.
I over filled with oil and checked that and it still happens. (no air bubbles or anything).
I have now stripped the rebound assembley and everything looks fine. Nothing appears to be damaged, missing or the wrong way round. I am happy to reassemble and keep riding as have mentioned nothing seems wrong and damping all seems to work.
Anyone with any ideas? Could it just be something to do having mid valve or just the shim configs for my weight?
Thanks for all help. The fork works great but would be nice to solve this as you can feel it slightly through the bars plus i find it all really interesting and am learning a lot.
I over filled with oil and checked that and it still happens. (no air bubbles or anything).
I have now stripped the rebound assembley and everything looks fine. Nothing appears to be damaged, missing or the wrong way round. I am happy to reassemble and keep riding as have mentioned nothing seems wrong and damping all seems to work.
Anyone with any ideas? Could it just be something to do having mid valve or just the shim configs for my weight?
Thanks for all help. The fork works great but would be nice to solve this as you can feel it slightly through the bars plus i find it all really interesting and am learning a lot.
ive just had the tools arrive today so im going to have a look inside. might also re-shim it for less dive.
the knocking from my cart is on the rebound action so that elka thing isnt helping me.
oh also, i changed the 5wt oil i had in there (wrong stuff as it has no 85/150 on it anywhere) for some 10wt shell advance stuff just to see how it works. surprisingly it worked great though im still going to be looking for the right stuff over here. i found some that craig reckoned would be fine but it turned out to be ridiculously expensive cause of odd postage charges.
anyway, off to have a wee look
the knocking from my cart is on the rebound action so that elka thing isnt helping me.
oh also, i changed the 5wt oil i had in there (wrong stuff as it has no 85/150 on it anywhere) for some 10wt shell advance stuff just to see how it works. surprisingly it worked great though im still going to be looking for the right stuff over here. i found some that craig reckoned would be fine but it turned out to be ridiculously expensive cause of odd postage charges.
anyway, off to have a wee look
Mine is on the rebound action as well but i think its just the same as the Elka with the shims popping on the piston when the fork rebounds. I cant think what else it could be.
Are you in the UK as you can get the Spectro 85/150 over here from http://www.battistinis.co.uk/ as they are the importer and distributer for it.
Are you in the UK as you can get the Spectro 85/150 over here from http://www.battistinis.co.uk/ as they are the importer and distributer for it.
yeah im from the uk, thanks for the link.
If it is the shims, its quite a noise for such a small thing to make and why is it only a few seem to make the noise?
edit - ok so i agree it is most probably the shims, actually read the thread properly..
how much of a seal should there be between the bushing and the damper shaft?
If it is the shims, its quite a noise for such a small thing to make and why is it only a few seem to make the noise?
edit - ok so i agree it is most probably the shims, actually read the thread properly..
how much of a seal should there be between the bushing and the damper shaft?
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Another thought is if there is bushing room the shaft will self center under pressure and resistance from speed and oil moving past so if its at slow speed theres q possability that there would be a clunk in transition from compression to rebound.
Oil can only escape by where theres room so if you have 2 round surfaces inside one another when one compresses it will push the inner circle center for oil flow
Oil can only escape by where theres room so if you have 2 round surfaces inside one another when one compresses it will push the inner circle center for oil flow
right, had it appart, cleaned everything including each shim and changed the mid valve to the firmest tune and still got a clunk..
so everything internally is sound.
just asked about the bushing as i noticed bubbles coming from it when i was getting all the fluid out. its fine i think
so everything internally is sound.
just asked about the bushing as i noticed bubbles coming from it when i was getting all the fluid out. its fine i think
what oil are you using out of curiosity
atm, 10 wt shell advance. you dont need to tell me its the wrong oil. ive been trying to find the right stuff for a while. at first i used the 5wt i used to use in the boxxers. i tried the 10wt stuff just out of curiosity and it seems to work a load better so ill use that till ive got the right stuff
Hi,
my name is Hendrik and i´m a german rider.
I ordered a ava cartrigde for my boxxer and in gereral i am happy with this decision.
Only one thing confuses me and therefor i want to ask you for help:
When the terrain gets rough and fast (many fast bumps as rocky sektions and fields of roots) the cartridge looses it damping almost completely.
Then there ist no compression or rebound resistance.
After a while or after some slow compressions with my hand it begins to build up some damping resistance.
I set the oil to an higher level but the problem occurs again. The change to another oil type of 5wt makes it slightly better but the main problem of less damping characteristic still occurs.
What do you think is the problem? Bubbles? Any internal oil lost or dislocation?
What kind of oil do you use. Any german or european riders here who can give me a tip for a good oil available from germany.
Many thanx for your help
Hendrik
my name is Hendrik and i´m a german rider.
I ordered a ava cartrigde for my boxxer and in gereral i am happy with this decision.
Only one thing confuses me and therefor i want to ask you for help:
When the terrain gets rough and fast (many fast bumps as rocky sektions and fields of roots) the cartridge looses it damping almost completely.
Then there ist no compression or rebound resistance.
After a while or after some slow compressions with my hand it begins to build up some damping resistance.
I set the oil to an higher level but the problem occurs again. The change to another oil type of 5wt makes it slightly better but the main problem of less damping characteristic still occurs.
What do you think is the problem? Bubbles? Any internal oil lost or dislocation?
What kind of oil do you use. Any german or european riders here who can give me a tip for a good oil available from germany.
Many thanx for your help
Hendrik
First off make sure its fork cartridge oil with anti foaming properties or you can foam and lose damping.
Make sure oil height is correct to avoid top out suction won't effect mid or bottom stroke just the top out
I use golden spectro 85/150 5w but its designed for cartridges and has anti foaming agents in it. (I saw 007 swimming around in my bottle
)Somewhere in here is a list of available oils for it, possibly one or 2 is available there maxima' belray?
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Sounds like the oli is foaming. What type of oil are you using? And did you have the fork fully extended when closing the top cap of the damping leg to prevent underpressurizing the leg?
Hi,
first, thanks for your answers.
I used the 5wt Maxima fork oil and the effect of loosing the damping was enormous. After changing the oil type to a 5wt Wilbers fork fluid (available here in germany) the effect decreased, but was not away.
I think all of the fork oils have anti foaming properties.
Maybe i did not fully extend the fork before locking the top cap. I will try this. Oil level ist correct.
I will see to get another type of fork oil.
thank you
first, thanks for your answers.
I used the 5wt Maxima fork oil and the effect of loosing the damping was enormous. After changing the oil type to a 5wt Wilbers fork fluid (available here in germany) the effect decreased, but was not away.
I think all of the fork oils have anti foaming properties.
Maybe i did not fully extend the fork before locking the top cap. I will try this. Oil level ist correct.
I will see to get another type of fork oil.
thank you
i have this one in mine:
http://www.offroadzentrale.de/Maxima-RACING-FORK-FLUID-Racing-Gabeloel-1-Liter
golden spectro is not avaiable around here as far as i know
http://www.offroadzentrale.de/Maxima-RACING-FORK-FLUID-Racing-Gabeloel-1-Liter
golden spectro is not avaiable around here as far as i know
Just remember using the weight printed on the bottle is a bad way to compare different brands, have a look at this chart from PVD's website:
http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid
You can see that different manufacturers Weights are all over the place. You should be using the CST value @40C (Our forks' internal temperature shouldn't change that much) of the oil for comparison, if you can't find the CST for a particular oil then the manufacturer needs a clue, don't buy it.
I use a mixture of Motorex 7.5w and Motorex 2.5w (20%, 80% from memory) to reach the recommended Golden Spectro 16.9 CST in my 35mm Boxxer & Avalanche. Works perfectly.
http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid
You can see that different manufacturers Weights are all over the place. You should be using the CST value @40C (Our forks' internal temperature shouldn't change that much) of the oil for comparison, if you can't find the CST for a particular oil then the manufacturer needs a clue, don't buy it.
I use a mixture of Motorex 7.5w and Motorex 2.5w (20%, 80% from memory) to reach the recommended Golden Spectro 16.9 CST in my 35mm Boxxer & Avalanche. Works perfectly.
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thats interesting. i weight 161 lbs, i have the medium(red) spring in my boxxers which gives me 28% sag and im running shell advance fork 10 to get the level of damping im after..
golden spectro 85/150 - 16.9
shell advance 5 (the first i tried, nowhere near enough damping) - 33.05
shell advance 10 (the one im running) - 38.97
err???
could the higher viscosity result in more fluid being forced past the highspeed shims and so greater fluid flow -more dive?
golden spectro 85/150 - 16.9
shell advance 5 (the first i tried, nowhere near enough damping) - 33.05
shell advance 10 (the one im running) - 38.97
err???
could the higher viscosity result in more fluid being forced past the highspeed shims and so greater fluid flow -more dive?
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highspeed shims are a blow off valve. oil flows past them when there is too much oil flow for it all to go through the lowspeed needle valve/port/whatever.
it takes more force to push a thicker liquid through a small hole than it does to push a thin liquid through the hole. the shell oil is nearly twice as viscous as the golden spectro.
the shell oil is not thin enough for it to have enough flow through the low speed needle valve so its being forced past the high speed shims too soon resulting in greater fluid flow on low speed fork compressions.
im really struggling to type whats in my head. ill email avy
it takes more force to push a thicker liquid through a small hole than it does to push a thin liquid through the hole. the shell oil is nearly twice as viscous as the golden spectro.
the shell oil is not thin enough for it to have enough flow through the low speed needle valve so its being forced past the high speed shims too soon resulting in greater fluid flow on low speed fork compressions.
im really struggling to type whats in my head. ill email avy
Lol don't worry typing and talking is overated, just point to stuff grunt and or follow up with some hitting we'll understand.
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I think I understand what you are thinking, but it doesn't work that way. The damping force is not going to be reduced when the shims start to bend, the force is just not growing exponentially like it would if there were no shimmed blow-off port.
****in wooo, sorted my knocking i think! i was staring at the midvalve shim stack table and noticed the float in all of them is only 0.35mm to 0.6mm, pretty small. tore the forks appart again, and it looked far more than the 0.35mm i needed for the stack im using. so i put a couple more shims on the spring side of the check plate, think they were 0.1mm thick. ill need to measure the float properly at some point but anyways, knock is gone and the fork feels amazing.
Good going, glad it worked out these are amazing g units and totally tuneable. Super glad you figured it out I'd have never guessed that so good for future reference.
im thinking that might be why they dove quite a bit aswell. ill need to check the fix with avy obviously
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Slipperysalmon what shim stack config have you used? I might try and adjust the midvalve in mine as thats the only stack that i havent played around with. Let us know what Avy say when you have spoke to them. Also can you breifly explain what you mean by 'float' as i am confused although it is late at night.
this will explain it better than i can:
http://www.supercross-online.de/Z/valving basics.htm
i figured that having too much float meant the valve was closing harsh and making that knock. i didnt have calipers handy to check the distance but im sure it was at least bigger than 0.5mm. making the check plate thicker makes the float smaller without changing the shimstack. i only put a couple of 0.1mm shims in till i can check the distance for sure.
i have the least dive, firmer mid shim stack on avy's table which should have 0.35mm float. i suspect i still dont have that small a float but ill not know till ive measured it properly.
ill email craig tomorrow, ive been out all night..
http://www.supercross-online.de/Z/valving basics.htm
i figured that having too much float meant the valve was closing harsh and making that knock. i didnt have calipers handy to check the distance but im sure it was at least bigger than 0.5mm. making the check plate thicker makes the float smaller without changing the shimstack. i only put a couple of 0.1mm shims in till i can check the distance for sure.
i have the least dive, firmer mid shim stack on avy's table which should have 0.35mm float. i suspect i still dont have that small a float but ill not know till ive measured it properly.
ill email craig tomorrow, ive been out all night..
or give him a call. if you havent talked to him already, he definitely knows his sh!t.
Have you had a reply from him yet? I am keen to know his thoughts although I am still going to have a play with what you have suggested and also changing the midvalve stack just to see what effect it has out on the trails.
haha just sent the email sorry. if youre going to play with the float get some calipers you can use to measure it before you do. i tried changing the stack before the float and it had no effect unsurprisingly on the knock
he says hes not sure why changing the float had an effect on the noise as theyve used all sorts of gaps with no effect on the noise. if it wasnt changing the float that sorted mine then im clueless as to what i did