[failure line]

HI,
i was servicing my shock('cuse im from iran and i have no access to servicing center) and accidently i droped my shim stack when i was opening it from the end of the piston rod so,
dose anybody know the shim stack setup for rc4 8.75*2.75 also its 2010 model?
thanks.

 

[Udi]

There are many different tunes each year so it is hard to know exactly which configuration you have.

The picture below might help get you started, the left side shows compression shims, right side rebound. The piston is shown compression side up (so the compression shims sit on that side). The piston bolt enters through the opposite side of the piston, and the rebound shims are generally thicker than the compression shims if you are stuck deciding whether a shim belongs in the rebound or compression stack.

Hope that is of some help, it should get you going again.

 

[kidwoo]

Hey udi, while you're digging through pics, how bout that boost valve removal?

 

[TrumbullHucker]

Hey udi, while you're digging through pics, how bout that boost valve removal?

oh lawdy me, this

 

[failure line]

There are many different tunes each year so it is hard to know exactly which configuration you have.

The picture below might help get you started, the left side shows compression shims, right side rebound. The piston is shown compression side up (so the compression shims sit on that side). The piston bolt enters through the opposite side of the piston, and the rebound shims are generally thicker than the compression shims if you are stuck deciding whether a shim belongs in the rebound or compression stack.

Hope that is of some help, it should get you going again.

hi and thanks for reply,
also can you recommend me a substitute oil rather than the fox 10w red?
one of my friends which been servicing a coupla rc4's said that i can use total lhm+ plus with no problem so what did you think?
thanks.

 

[Udi]

It's not ideal, LHM+ is a mineral oil (i.e. non-synthetic) whereas Fox Red 10wt is a fully synthetic oil, and its benefits are to do with shear stability - i.e. a better ability to maintain its permanent viscosity after being subject to high temperatures and forces. A low volume damper like a shock is pretty hard on oil.

Aside from that, the viscosity of Red is 47cSt@40C and LHM+ is significantly lower at around 18cSt - so you're going to have reduced damping. The temperature stability of LHM+ seems adequate so in that sense it will work, but I really would not recommend it.

Fox Red is the same as Silkolene "Pro RSF" 10wt so have a look around and see if you can get that. I doubt you will find many other alternatives that fit the factory specification.

 

[Kanye West]

The BelRay closest equivalent of their HVI oil works fine. I think it's the 10w.

 

[Udi]

Bel-Ray HVI 15w, "48-51cSt" looks like it'd be the closest match. The 10w is "32-35cSt", would probably work okay too.

 

[failure line]

what about sram pit.stop 10w?

 

[Steve M]

what about sram pit.stop 10w?

It's just relabeled Maxima RFF 10wt. Not suitable for use in your rear shock, the viscosity index is too low. What other brands do you have access to? We can help you find something from those brands.

 

[jstuhlman]

 

[failure line]

thanks for all the replys.
i have access to motorex fork oil but in 5w,total,mobil,shell,castrol,motul and....but the problem is that the import company's here dont have all the versions available, for instance we have the fuchs but they dont have Silkolene "Pro RSF".

 

[big-ted]

I can't believe no-one has suggested moar of them yet...

 

[TrumbullHucker]

I can't believe no-one has suggested moar of them yet...

 

[Steve M]

thanks for all the replys.
i have access to motorex fork oil but in 5w,total,mobil,shell,castrol,motul and....but the problem is that the import company's here dont have all the versions available, for instance we have the fuchs but they dont have Silkolene "Pro RSF".

Check this list of oil viscosity and viscosity index (VI) for a whole lot of suspension fluids. Pick one that's available to you that has a high VI (over 250, preferably over 300) that has a viscosity (in cSt at 40C) between 35cSt and 50cSt.
http://www.peterverdone.com/wiki/index.php?title=File:PVD-ISO-Viscosity-Data.gif

 

[failure line]

hi
thanks for the list
i changed the shock oil and felt it with air(150psi) butt the probelm is that is looses air and every time that i attach the pump it shows the zero psi also dose moving the piston rod before putting any air into it causes the shock to get air?

 

[Udi]

After pressurising the shock to 150psi, leave the valve cap off and drop it in a tub of water and watch to see if any air bubbles are escaping. If there is an external leak you should see it. If the valve core is leaking, you can replace it with a standard schrader valve core. It's also possible that it is leaking past the IFP o-ring internally, in which case you should replace that, however that's not common.

After assembling/filling the shock and setting the IFP depth, you should not move the shaft before pressurising it. This can definitely cause the oil to aerate, particularly if you move the shaft in the extension direction (as you draw a vacuum internally).

 

[failure line]

i just filled the shock and set the ifp at 36mm because the shock is 8.75*2.75 and i was put the shims according to this thread:
http://www.ridemonkey.com/threads/anyone-have-stock-shim-stacks-for-a-fox-rc4.265673/(shims seems to be the same size in diameter and quantity)
and then pressurised it with the pump and after compressing the shaft the adjusments seems to work ok but then i attached it to the bike and after any adjustment i do shock just feels the same way,so soft that i can move the shaft just by pressing the saddle with my finger?

 

[TrumbullHucker]

i just filled the shock and set the ifp at 36mm because the shock is 8.75*2.75 and i was put the shims according to this thread:
http://www.ridemonkey.com/threads/anyone-have-stock-shim-stacks-for-a-fox-rc4.265673/ shims seems to be the same size in diameter and quantity)
and then pressurised it with the pump and after compressing the shaft the adjusments seems to work ok but then i attached it to the bike and after any adjustment i do shock just feels the same way,so soft that i can move the shaft just by pressing the saddle with my finger?

link no work?

 

[failure line]

sorry thats the right one:
http://www.ridemonkey.com/threads/anyone-have-stock-shim-stacks-for-a-fox-rc4.265673/

 

[failure line]

After pressurising the shock to 150psi, leave the valve cap off and drop it in a tub of water and watch to see if any air bubbles are escaping. If there is an external leak you should see it. If the valve core is leaking, you can replace it with a standard schrader valve core. It's also possible that it is leaking past the IFP o-ring internally, in which case you should replace that, however that's not common.

After assembling/filling the shock and setting the IFP depth, you should not move the shaft before pressurising it. This can definitely cause the oil to aerate, particularly if you move the shaft in the extension direction (as you draw a vacuum internally).

i just filled the shock and set the ifp at 36mm because the shock is 8.75*2.75 and i was put the shims according to this thread:
http://www.ridemonkey.com/threads/anyone-have-stock-shim-stacks-for-a-fox-rc4.265673/ shims seems to be the same size in diameter and quantity)
and then pressurised it with the pump and after compressing the shaft the adjusments seems to work ok but then i attached it to the bike and after any adjustment i do shock just feels the same way,so soft that i can move the shaft just by pressing the saddle with my finger?