Fox van rc problem

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Fox van rc problem
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flag mudmurph
O+ FL
Posted: Apr 11, 2012 at 14:24 Quote
I run the shock on a trek session 8 2011, with a 400lb spring.
Is there supposed to be a small clunk noise almost a bump feel to when the shock goes past the 5-10% stroke mark? Im not to sure if its suppost to do it. You can push the shock up and down much easier, then when it goes past the ''bump'' it shock feels normal (more stiff)
flag vwcabrio82
O+
Posted: Apr 18, 2012 at 16:34 Quote
is it a 2011 shock?

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flag Liamcrook
Posted: Apr 19, 2012 at 3:34 Quote
No, it should definitely not do that!

Check you have some preload on the coil.

Check all your frame pivots and shock bushes to ascertain that the problem is definitely the shock itself.

If it is a problem with the shock then either strip it yourself if you are confident or send it to tf tuned.
flag mudmurph
O+ FL
Posted: Apr 19, 2012 at 11:08 Quote
yer its 2011, the preload is about half way down the thread, the shock feels fine when i am riding. i just notice it when going slower etc
flag vwcabrio82
O+
Posted: Apr 21, 2012 at 15:07 Quote
Liamcrook wrote:
No, it should definitely not do that!

Check you have some preload on the coil.

Check all your frame pivots and shock bushes to ascertain that the problem is definitely the shock itself.

If it is a problem with the shock then either strip it yourself if you are confident or send it to tf tuned.

best advise really... could be something unrelated... or perhaps some stiction.

also try to relax the preload on the coil... see if the stiction is still present. could need to be lubed inside.
flag freeridermx
Posted: May 29, 2013 at 8:30 Quote
I have the same shock, but mine just feels too stiff. I`ve already tried adjusting the compression and rebound and just can`t have a smooth ride. I`m ridding a 2012 Intense Uzzi.
Any suggetions ?
flag mudmurph
O+ FL
Posted: Aug 29, 2013 at 3:47 Quote
sent it off to mojo to get a service and i told them about the problem. They dyno tested it and replaced some bits and they said its working fine, replaced all the pivot bearings and bushings and its still doing it?
flag vwcabrio82
O+
Posted: Aug 31, 2013 at 18:24 Quote
wow this is such a lingering problem.

perhaps there is a bend in one of the frame linkages? something there has to be binding up.
flag mwilliams
Posted: Sep 1, 2013 at 7:21 Quote
What about running a different air pressure in the resivoir?
flag BryanBobo
Posted: Apr 16, 2014 at 6:01 Quote
Ever figure out what the issue was here? I am having an issue with my Van Rc as well (not sure if its the same). But when I step off my bike and press down on my seat I get a small hitch before the bike moves through its travel.
flag madmax650
Posted: Apr 16, 2014 at 8:48 Quote
You may have lost the nitrogen charge in your shock and the oil has possibly emulsified?..
flag BryanBobo
Posted: Apr 17, 2014 at 4:29 Quote
madmax650 wrote:
You may have lost the nitrogen charge in your shock and the oil has possibly emulsified?..

I would think the oil emulsification might take a while? (Not sure). The shock is only a little over a year old and has relatively limited use, but the nitrogen charge is an interesting idea, any idea if there is a way to check that? I would rather not spend $100 on a rebuild if I don't have to
flag jonbikes
Posted: Apr 17, 2014 at 9:22 Quote
Look at the leverage ratio curve of the frame. Some designs have a curve which alters greatly through the stroke causing sudden stiffenening feelings, giant glory's are a premium example of this. They do this to try and gove you a supple stroke off the top but maintain some bottom out controll later in the stroke.

Emulsification is not really the proper term for what happens when a shock has no pressure behind the ifp, aka nitrogen charge. The charge is there to keep a positive pressure on the oil during the rebound stroke to prevent a problem called cavitation. Cavitation is when a fluid is put under a vacuum stronger than the fluids vapour limit and the gasses disolved begin to come out of solution and form vapour pockets (much different than an air bubble introduced from an atmospheric source which is what we call an emulsion of air and water, also oil and water is a good example of an emulsion where as salt goes into solution with water and is dissolved. ). When a positive pressure is re applied to the vapour pocket it colapses and causes a shock wave in the fluid which effectively sand blasts away the internal parts of whatever the fluid is housed in; in this case your soon to be cooked rear shock.

http://en.m.wikipedia.org/wiki/Cavitation
flag madmax650
Posted: Apr 17, 2014 at 10:42 Quote
Cavitation. Thank you..haha emulsify ..smh
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